ú Newsgroup: sci.med ú Message-ID: <1993Mar09.122423.11198@omen.UUCP> ú Subject: My New Diet --> IT WORKS GREAT !!!! The book is "Dr. Atkins NEW Diet Revolution", M. Evans & Co New York, ISBN 0-87131-679-X The book is $20 hardcover. Atkins recommends a high level of vitamin/mineral supplementation as described in his book. I didn't find any mention of a "Water Diet" in either his 1972 book or his current book. He does mention on page 102 that uric acid may be elevated, but can be controlled by slowing weight loss. Citric acid causes problems with a ketogenic low carbohydrate diet in about 40% of individuals. Even the small amount in lemon slices has been reported to cause a problem. Most diet sodas have citric acid, so check the label. If you are one of the 40% that is sensitive to citric acid while on a ketogenic diet, Diet Pepsi will definitely knock you out of the Pepsi Generation. ============================================================================== ú Subject: Adiposity 101 1/4 Here's the latest "Adiposity 101" as promised. Not necessarily everything one needs to know about adiposity but more than some know. Some subjects have been left out to save space. I will announce an ftp location for the troff/nroff source and postscript output shortly. New or revised items are marked with @ characters. X X Adiposity 101 X X Chuck Forsberg X X Portland Oregon X X 1. FOREWORD X This paper is a summary of recent progress in obesity research. It identifies topics and issues concerning obesity. The reader should study the references given below if questions or doubts remain. X The purpose of this paper is to set out the case for new weight loss technology and thereby give hope to the millions of fat Americans for whom conventional weight loss technology has been ineffective at best. X Formatted 3-9-93. X X 2. ROSETTA STONE X Anorectic: appetite suppression X Anorexiant: substance that suppresses appetite X Adipocyte Hyperplasia: Excessive number of fat cells, as much as ten times normal. X Endomorph: a person with a heavy body build, in contrast to mesomorph (muscular) and ectomorph (skinny). X Hyperphagia: overeating X In vivo: in the body In vitro: in a test tube X Lipogenesis: Storing of energy in fat tissue X Lipolysis: Draining energy from fat tissue X Panniculus adiposus: overhanging belly X Weight rebound: a net adiposity increase in a diet-regain cycle, sometimes confounded by a net loss of lean tissue. X Adipose Cell: There are two types of adipose (fat) cells, White Adipose Tissue (WAT) and Brown Adipose Tissue (BAT). The body uses WAT to store energy for use in famines; BAT burns energy to maintain body temperature. Severe obesity is caused by too many White Adipose Cells. X Human adipose tissue in vivo does not have the simple metabolic pattern that might be expected from studies of X X X X X X X X X X X Adiposity 101 2 3-9-93 X X X adipocytes in vitro. It is engaged in a variety of metabolic exchanges. TAG, glucose, oxygen, acetoacetate, and 3-hydroxybutyrate and acetate are all extracted from from the blood. NEFA, glycerol, lactate, and carbon dioxide are released. (Proceedings of the Nutrition Society 1992: 51, 409-418) X Glucose: (dextrose) found in fruits and other foods, is the end product of carbohydrate metabolism. Blood glucose is the primary source of energy in animals. Glucose is converted to glycogen and stored in the liver, muscles, and fat tissues. Blood glucose levels are of great interest in adiposity and diabetes. Low blood glucose from fasting or other dietary restriction can induce headaches, low spirits, and compulsion to restore normal glucose levels by eating more. To convert from the mmol/L SI units found in research papers to the familiar mg/dl used by American physicians, multiply by 18. X Metabolic needs of the body are provided by the degradation of glucose and free fatty acids [FFA]. Most tissues can use both glucose and FFA for their energy needs, but the brain and nervous system can only use glucose. When dietary intake does not permit sufficient production of glucose, body protein is sacrificed to make it. X Fat Free Mass (FFM) is everything that is not fat. Water constitutes about 73 per cent of FFM. Glycogen, another constituent of FFM, is stored in the liver and muscle as a reservoir of glucose for metabolic energy. Many papers do not distinguish between FFM and muscle tissue. To complicate the issue, obesity tissue contains significant protein and other substances in addition to fat. FFM measurements must be used with caution as controversy remains about its definition and measurement techniques. X Body Mass Index (BMI) is a measure of the percentage of fat to total body mass. BMI is weight in kilograms divided by height in meters, squared. (Multiply by 704 if using inches and pounds.) BMI is a relatively height and bone-density independent measure of adiposity (fatness). BMI is more highly correlated with body fat than other indices of height and weight. BMI should not be used in individual cases unless confirmed by unretouched photographs or other indications as it does not distinguish between mesomorphs and somewhat overweight men. X Morbid obesity: Obesity severe enough to directly limit the victim's health or quality of life. X Refactory: Adjective indicating the condition reasserts X X X X X X X X X X X Adiposity 101 3 3-9-93 X X X itself, precluding long term relief. X Two major enzymes involved in the regulation of uptake and egress of fatty acids from fat cells are LipoProtein Lipase (LPL) (stores fat) and Hormone Sensitive Lipase (HSL) (mobilizes fat). X @ Insulin promotes fat deposition, differentiation of white fat cells, glucose uptake by muscle tissue, inhibits growth hormone release, inhibits the fat releasing action of catecholamines, and lowers glucose production in the liver. Abnormally high levels of insulin (hyperinsulinaemia) precedes obesity and hypertension. In hyperinsulinaemia, the liver and muscles become resistant to insulin, shunting dietary energy to fat stores. Abnormally low levels of insulin caused by untreated type I diabetes can lead to lipoatrophy (loss of fat tissue). Serum insulin concentration varies directly with the carbohydrate content of the diet. X @Proinsulin is one of many metabolically defective insulin- like substances produced by the pancreas in addition to insulin. The ability to distinguish insulin from the other substances is new and not widespread. It is now thought that most Type II diabetics are in fact absolutely insulin deficient. (The Lancet, Feb 11 1989, 293--5) X The pituitary gland releases Human Growth Hormone (HGH) in bursts, mostly during the early hours of sleep. Human Growth Hormone promotes muscle growth and fat loss. Also called somatropin. X DHEA is a hormone that reduces fat tissue size and serum cholesterol. X Kilo Joule: some papers use kilo Joules (kJ) to measure food energy instead of kilocalories (kcal), or "calories" as used by the lay press and food labels. To convert from kJ to kcal ("calories"), multiply by 0.24. X Programming: A permanent or long-term change in the structure or function of an organism resulting from a stimulus or insult acting at a critical period of early life. X X X X X X X X X X X X X X X X X X Adiposity 101 4 3-9-93 X X X 3. ENERGY BASICS X @ X Interesting Parameters for Dietary Macronutrients X ______________________________________________________________________ |Parameter | Protein | Fat | Carbohydrate | Ethanol | |________________________|_________|_________|______________|_________| |Gross energy kcal/g | 5.5 | 9.2 | 3.9 | 7.1 | |Digestibility % | 92 | 95 | 99 | 100 | |Metabolic energy kcal/g | 4 | 9 | 4 | | |Cost of storage kcal/g | 6 | 1.4 | 3.4 | | |Weight change g/kcal | ? | .21-.12 | .30 | NIL | |________________________|_________|_________|______________|_________| X Gross energy is the heat of combustion, possibly useful information when investigating spontaneous combustion of humans. X For the body to use these nutrients, they must be digested (an imperfect process). Some energy is required to convert carbohydrate to triglycerides in fat storage. Energy is also required to store dietary fat in adipose cells, and to store protein in lean tissue. (Obesity and Leanness - Basic Aspects) X In the human body, dietary macronutrients affect fat stores (body weight) in individual ways. On a high-fat diet, 4703 to 8471 excess calories were required for each kilogram of added weight. (Department of HEW Pub NIH 75-708 Government Printing Office, 165-86) On a low carbohydrate VLCD, replacing fat calories with 8 g/day of equivalent carbohydrate calories reduced weight loss by 1.68 kg, corresponding to 3300 calories of carbohydrate/kilogram, possibly 2500 calories per kilogram for carbohydrate alone. (Am J of Clin Nutr 1992;56:217S-23S) The action of insulin and other hormones may account for the contradiction between the energy content of fat and carbohydrate compared with their dietary effects on human weight control. X @Ethanol is another energy-providing substrate, at least in so far as energy is released when it is burnt in a bomb calorimeter. Some dietary studies show that increased ethanol consumption is not accompanied by the expected change in body weight. Pathways have been suggested by which ethanol may be oxidized without generation of useful energy. From a biochemical point of view, ethanol demonstrates the inapplicability of linking the "energy value" of a nutrient (kilocalories) with storage of lipids in fat tissue. After an overnight fast, there was no tendency for fat storage after a 1400 kJ ethanol load, in X X X X X X X X X X X Adiposity 101 5 3-9-93 X X X marked contrast to fat storage from a 1160 kJ monohydrate load. (Proc of the Nut Soc 1992 51, 409-18) X X 4. THE BIOLOGY OF ADIPOSITY X 4.1 SET POINT X One cannot understand current obesity research without some essential knowledge of human energy metabolism and how it is regulated. The body gets its energy from dietary protein, carbohydrate and fat. The body stores energy as glycerol, lean tissue and fat. The partitioning of available energy sources between energy output (work), muscle and fat storage vary greatly between individuals. These differences are primarily genetic in origin, but are also caused by metabolic and nutritional abnormalities during gestation and infancy. X Muscle tissues burn carbohydrate and fat for energy. When energy expenditure exceeds dietary input, stored glycogen, fat stored in adipose cells, and lean tissue are cannibalized to make good the energy shortfall. X Animals regulate their body fat stores within fairly narrow limits. This regulation is automatic, not requiring conscious intervention. Changes in energy balance are compensated for by changes in appetite and metabolism. A bout of flu reduces energy intake at the same time the body's fever increases energy expenditure; the lost weight is regained afterwards. Likewise a large Thanksgiving meal raises metabolism (that's why one feels warmer) and depresses appetite for a while. The usual body weight that a person maintains automatically is called the SET POINT weight. X The SET POINT THEORY of body weight regulation postulates that a biological servo system affects energy expenditure, hormones, fat cell receptors, appetite, and other metabolic parameters to maintain a constant body weight (set point) resistant to changes in energy input or exertion. X For many obese individuals, their set point is the stable weight to which they repeatedly return to after dieting. Set point theory explains why the calorie loss of moderate exercise provokes an increase in appetite and/or slowing of metabolism, preventing major weight loss. X Healthy male subjects who have no history of dieting or weight concerns have a strong caloric compensation. (American Journal of Clinical Research subjects reduced X X X X X X X X X X X Adiposity 101 6 3-9-93 X X X intake of other foods after required eating of food containing 22%-52% of their baseline energy intake. Subjects compensated for the covert caloric dilution of one third of the available items by increasing intake of non diluted items. Nutrition 1992;55;331-42) X The LPL study mentioned below supports the much-debated "set point" theory, which holds that inner mechanisms set a person's weight at a predetermined level and if anything is done to change the weight, the body will adjust to restore fat content to the set point. X "I regard body temperature, which stays around 98.6 degrees F, to be a set point. Weight doesn't have a set point in that sense," says Xavier Pi-Sunyer, M.D., director of the Obesity Research Center at St. Luke's-Roosevelt Hospital Center in New York. If there is a set point for weight, it generally seems to move in one direction--that is, the body will not make adjustments to counteract a large weight gain but will fight efforts to lose the weight. "When a person gains weight and stays at that weight a while, the body will defend that weight. It becomes the new 'set point'," explains Pi-Sunyer. X Aside from the action of LPL, the body uses other adaptive mechanisms when food intake is reduced. To cite just two of them: Dieting depresses the metabolic rate so that calories are burned more slowly, and as fat cells shrink, they become more responsive to the action of insulin and do not release their contents as readily. (FDA CONSUMER) X The set point theory of body weight regulation is based on a large body of empiric evidence. (Weigle DS; Human obesity - Exploding the myths. Western Journal of Medicine 1990 Oct; 153;421-428) X 4.2 Rats, Pigs and Blimps X Mice, rats and pigs are commonly used in adiposity research because their metabolisms resemble those of humans. X Wild rats never exceed 10% body fat, even when fed high fat diets. Some strains have been bred to mimic the metabolism of obese humans. The best known strains are the obese ob/ob mouse and the fatty fa/fa Zucker rat. These strains become obese even when restricted by pair-feeding to the caloric intake of lean littermates. X The ob/ob mouse fails to survive in the cold because it cannot generate sufficient heat by burning fat. X X X X X X X X X X X X Adiposity 101 7 3-9-93 X X X @Nitrogen balance studies have shown that the obese Zucker rat tends to deposit amino acid carbon skeletons in the form of fat, rather than muscle protein. Their muscles are smaller and contain less protein than those of lean counterparts. The obese rat also has less lean body mass, a reduced rate of protein deposition, and a reduced rate of protein synthesis in skeletal muscle; the decreased rate of protein synthesis is already present in the obese rat before weaning. (Int J of Obes 1992,16: 213-8) X Obesity in Zucker fa/fa rats is thought to result from the combination of two recessive genes (fa/fa). Zucker rats can survive in the cold, yet they attain the obese state with normal diet and exercise. "The obesity of the Zucker rat ... is inherited as an autosomal recessive mutation. It is thought to be the initiated by a single gene defect (fa) the nature of which remains totally unknown. These rats develop a syndrome that closely resembles human obesity. Hyperphagia, hyperinsulinemia and normoglycemia, hypertriglyceridemia, hypertrophy and hyperplasia of fat cells as well as the development of type II diabetes and renal complications are common features to both [rat and human] species." p. 679, Journal of Lipid Research, 1992. A 25-fold increase in the amounts of the enzyme adipose tissue Fatty Acid Synthetase (FAS) apparently causes this obesity. X High protein requirements could provide a partial explanation for the hyperphagia of genetically-obese Zucker rats. These mutants oxidize amino acids in preference to fats and therefore growth of lean body mass is limited. In order to obtain sufficient protein for normal growth the Zucker overeats, and the excess energy ends up as fat. It is claimed that the hyperphagia is almost completely abolished when these animals are fed very high protein diets, and weight gain is then diminished. (p. 33, Obesity and Leanness - Basic Aspects) "FAS overactivity will act as a metabolic drive, channeling dietary substrates [food energy] into adipose tissue fat stores; this would happen whatever the food intake level of the rats, in good keeping with the well-established observation that hyperphagia [overeating] is not a necessary precondition for the development of Zucker rat obesity. The shunting of nutrients into adipose tissue would entail two physiological consequences, a compensatory hyperphagia and a secondary hyperinsulinemia." @Human FAS activity was higher in obese subjects than in lean controls. (Metabolism 1991;40;3:280- 5) X @ The sand rat (Psammoys obesus) becomes obese, hyperinsulinaemic, and insulin resistant when shifted to a high energy diet, a syndrome which also affects Aboriginal X X X X X X X X X X X Adiposity 101 8 3-9-93 X X X Australians and Pima Indians. X The choice of animal strain is important to obesity experiments. Results obtained with obese rats are more relevant to obese humans than results obtained with Wistar or Sprague-Dawley (genetically thin) rats. X 4.3 Brown Adipose Tissue (BAT) X Brown Adipose Tissue (BAT) generates heat with Non Shivering Thermogenesis (NST) by burning calories without physical motion. X 4.4 White Adipose Tissue (WAT) X Obesity results from an excess of white adipose tissue (WAT). X WAT cells are not simple storage tanks. They are active, living cells. They destroy DHEA and Growth Hormone. They convert steroids that promote muscle development to estrogen. White Fat cells compete with lean tissue for nutrients, impeding muscle development. X Reduction of fat cell numbers (see below) causes permanent fat loss while weight loss techniques that do not reduce the number of fat cells are temporary. This suggests that fat cells themselves enforce the elevated "set point" in many individuals. "The evidence is strong that the defense of body weight against a reduction in diet palatability is much stronger in animals and humans with normal size or small fat cells than in individuals with enlarged fat cells. This seems to be the case regardless of fat cell number. One wonders, therefore, whether reduction in fat cell size might be the event that normally gives rise to the food hoarding response in food-deprived rats." (Clinical Neuropharmacology Vol 11 Suppl 1 p. S1-S7) X 4.5 Preadipocytes > Fat Cells X White fat cells begin life as PREADIPOCTYES. X Human adipose tissue contains a pool of tiny precursor cells (preadipocytes) which can be converted to adipocytes (fat cells) in the presence of glucocorticoids and insulin. (Journal of Clinical Endocrinology and Metabolism, 1987). X The role of insulin in fat cell proliferation, reported in many papers, explains the effect of dietary sugar and carbohydrate on the development of obesity. This would also explain why excessive insulin levels in the gestating human X X X X X X X X X X X Adiposity 101 9 3-9-93 X X X baby induce obesity that appears after several years. X The future adiposity of suckling pigs can be predicted by measuring the ability of the suckling's blood to differentiate preadipocytes into full size fat cells in a test tube. The preobese sucklings had low levels of growth hormone. X Epidermal Growth Factor (EGF) dramatically inhibits differentiation of preadipocytes into fat cells. Obese mice have EGF levels as much as 80% less than their lean littermates. Fat pads of EGF treated rats weighed only half as much as untreated rats, contained only 25 percent as many mature adipocytes, and accumulated only 20 per cent as much lipid. X Preadipocytes isolated from fat deposits in different parts of the anatomy appear to be different. This could explain the strong heritability of body fat distribution. Preadipocytes isolated from obese rat strains change into fat cells more easily than normal. X 4.5.1 Size and Number of Fat Cells Is obesity caused by an excess number of fat cells or by gross enlargement of a normal number of fat cells? The answer to this question has heavy implications for the possible success of various weight loss strategies. X Lean individuals have 20 to 40 billion fat cells. Fat cells can expand to no more than twice normal size. Some obese subjects have ten times as many fat cells as normal. Bjorntorp and Sjostrom (METABOLISM V20;7;703) have observed an association between high fat cell numbers (hyperplasia), more severe obesity, and childhood onset obesity. A number of studies have found that subjects with childhood onset obesity have more difficulty losing weight and are more likely to gain more weight than they lose dieting, putting them at risk of hyperobesity from diet cycling. X A study published in the Proceedings of the 5th International Congress on Obesity showed that obese subjects who had lost weight had fat cells 25 per cent smaller than those of marathon runners who had half the total body fat. The dieters had twice as many fat cells as the athletes. X @The defense of body weight against a reduction in diet palatability is much stronger in animals and humans with normal size or small fat cells than in individuals with enlarged fat cells. (Clinical Neuropharmacology Vol 11 Suppl 1 S1-7) This would explain why it is much more difficult for obese individuals to reach and maintain ideal X X X X X X X X X X X Adiposity 101 10 3-9-93 X X X weight. X 4.6 Fat Cell Receptors X Fat cells gain and lose weight by passing lipids through receptors. One type of receptor removes lipids from the blood stream and another type allows the body to access the energy stored in the fat cells with a resulting loss of weight. Geographic distribution of fat, including "love handles" that do not respond to extreme dieting, is believed to result from local variations in these receptors. X The numbers and efficiencies of fat cell receptor types change with repeated dieting, slowing weight loss on successive diets and promoting weight gain. X 4.7 Fat and Carbohydrate Oxidation X A low metabolic rate is a risk factor for subsequent weight gain. A low ratio of fat to carbohydrate oxidation independent of energy expenditure is also a risk factor for weight gain. In response to weight gain, both the metabolic rate and fuel mix oxidation become "normal" for the new body weight. (Progress in Obesity Research 1990, p. 180) X The lower thermic effect of food in the obese is uncorrected by weight loss, and thus it is a contributor to obesity rather than a consequence of obesity. (Am J of Clin Nutr 1992;55:924-33) X 4.8 Muscle Fibre Type X The April 19 1990 Lancet reports that skeletal muscle fibre type is directly correlated with body fatness. Lean subjects have more "slow fibres" well endowed with mitochondria that use fatty acids as energy source. Corpulent subjects have fewer "slow fibres" but more "fast fibres" that only burn glucose; they cannot burn fat for energy. (See EXERCISE, below.) The proportion of fibre types is a nearly linear function of BMI. All of the subjects were sedentary, ruling out any effect from endurance training. (1D-5) (1D-7) X A low ratio of fat to carbohydrate oxidation independent of energy expenditure is a risk factor for weight gain. (p. 180, Progress in Obesity Research 1990) X It is now recognized that obese trauma patients require special dietary intervention because their bodies cannot use the energy stored in fat for healing the way thin people do. (Journal of Clinical Investigations, Jan 1991) X X X X X X X X X X X Adiposity 101 11 3-9-93 X X X 5. FORTUNE OF BIRTH X 5.1 Types of Adiposity X Research over the last decade has shown that most fat people did not get fat because they ate too much, ate the wrong things, or exercised too little. Rather, they became fat because their bodies put too great a fraction of their food energy into fat. This research is discussed in later chapters. X Experiments with controlled overfeeding of lean subjects demonstrate an increase in body metabolism that restores normal weight when overfeeding ceases. In a 1986 Dutch study, men who experienced many life events in a short period showed a gain in body mass. A year later this weight gain had disappeared in almost all subgroups of these men. The exception was the subgroup that tried to lose weight by dieting; those who dieted gained yet more weight. (International Journal of Obesity (1988), 12, 29-39.) X Lean individuals' self-recovery from overeating is exploited in ads from Jennie Craig and other diet providers that claim long term weight loss. None of the well known "before/after" diet celebrities such as Art McMahon had childhood onset obesity. X @Much remains to be learned about human genetics, but it has already been learned that individuals with the HLA Aw30 allele have a 2.61 relative risk for obesity. (Human Heredity 1989;39(3):156-64) X X Experiments by Meier, Cincotta and Lovell suggest obesity and associated type II diabetes are the result of defective circadian [daily cycle] neuroendocrine rhythms. X X 5.2 GENETICS X The conclusion of current research is that individual differences in Body Mass Index (BMI) are mostly the result of genetic factors. Obesity is now thought to be the result of a pairing of normally recessive genes (fa/fa). X "Previously, researchers at the University of Iowa found evidence of a recessive obesity gene (the child needs one copy of the gene from each parent to have the tendency towards overweight). A study of 277 school children and their families showed a pattern of obesity that followed the classic model for recessive inheritance. X X X X X X X X X X X Adiposity 101 12 3-9-93 X X X However, it is likely that a number of genetic mechanisms exert influence on weight, among them genes that dictate metabolism and appetite. One that is being investigated actively is the gene that codes for lipoprotein lipase (LPL), an enzyme produced by fat cells to help store calories as fat. If too much LPL is produced, the body will be especially efficient at storing calories [as fat]. X LPL is partly controlled by reproductive hormones (estrogen in women, testosterone in men), so gender-based differences in the activity of the enzyme also factor into obesity. In women, fat cells in the hips, thighs and breasts secrete LPL, while in men the enzyme is produced by fat cells in the midriff region. Fat cells in the abdominal area release their contents for quick energy, while fat in the thighs and buttocks are used for long-term energy storage. Thus, a man can often pare his paunch more readily than a woman can shed her saddlebags. X LPL also makes it easier to regain lost weight, according to a study conducted at Cedars-Sinai Medical Center in Los Angeles and reported in the April 12, 1990, issue of the New England Journal of Medicine. Nine people who lost an average of 90 pounds had their LPL levels measured before dieting and after maintaining their new weights for three months. The researchers found that levels of the enzyme rose after weight loss, and that the fatter the person was to start with, the higher the LPL levels were--as though the body was fighting to regain the weight. They believe that weight loss activated the gene producing the enzyme. This may be one reason why it is easier for a dieter to regain lost weight than for someone who has never been obese to put weight on." (FDA CONSUMER) X Two studies published in the New England Journal of Medicine illustrate the point. X In "The body-mass index of twins who have been reared apart", the rearing environment was shown to have no effect on BMI. Adoptees of fat parents were no fatter then adoptees of skinny parents. In other words, if you're fat, it wasn't because your mother fed you too many cookies and it wasn't because your father didn't make you exercise. X In a followup paper given at the 6th International Congress of Obesity, p. 670, the heritability estimate for obesity at age 45 comes to 0.84. Compare this to some other commonly accepted heritability estimates: Coronary, .49, Schizophrenia, .68, Hypertension, .57, Alcoholism, .57, Cirrhosis, .53, Epilepsy, 0.50. X X X X X X X X X X X X Adiposity 101 13 3-9-93 X X X The plots of parent/offspring weights in the above study bear close inspection. The plot of biological parents and adoptees shows the (by now) well known nearly straight line relationship between parents' adiposity and that of their children. The plot of adoptive parent weight and adoptee weight shows a slight negative trend for females, and no trend for males. So much for fat mothers passing bad habits on to their children. X "the genetic relationship fully accounts for the familial resemblance in body mass index among adults." X A study of lean and overweight male Army personnel was designed to prove that the overweight valued good health less than normalweights, and practiced less healthy lifestyles. To the researchers' surprise, there were no significant differences between overweight and normalweights on these attitudes. X "environmental effects shared among family members are irrelevant in the determination of weight and obesity." (International Journal of Obesity 1992 16 657-666) X In "The response to long-term overfeeding in identical twins", 12 pairs of identical male twins were overfed and kept sedentary under close supervision. There was a 3 to 1 ratio in weight gain between the easiest gainer and the slowest gainer. Those who gained the most fat gained less muscle than those who gained the least fat. Ten of the 12 pairs of identical twins gained almost identical amounts of weight. X The overfeeding study is interesting because of its sample selection. None of the subjects had any history of obesity whatsoever, not even in their families. One can but imagine what that 3 to 1 difference in weight gain and 16 to 1 difference of lean/fat gain would have been if overweight subjects had been included. X The appearance of these papers in the May 24 1990 New England Journal of Medicine prompted several submissions questioning the papers' findings. These letters and the authors' rebuttals were printed in the Oct 11 1990 edition. X The Sep 1990 Science News reported a very wide difference in the amounts and types of tissues added in response to overfeeding. In this study, thin people actually added more weight than fat people did, but the thin people added weight mainly as lean tissue instead of fat. Data from "lean hungry" types that gained little weight were excluded! X X X X X X X X X X X X Adiposity 101 14 3-9-93 X X X The obese (and pre-obese) differ from lean persons in other ways. Their muscle cells do not burn fat well. DHEA and growth hormone levels are low. Their fat cells spontaneously multiply under conditions when those of of lean persons do not. Metabolic differences are evident even before birth. These factors are described elsewhere in this document. X Obese and lean persons do not share the same genetic heritage. X 5.3 SYNDROME X X Syndrome X loosely refers to a genetic predisposition to glucose intolerance, hyperinsulinaemia, obesity, hypertension, and type II diabetes. X A study by teams in Australia and the United States confirms a genetic defect in certain populations with a high risk of developing obesity-linked disease such as diabetes. The research defined the defect in a critical metabolic step in the body's capacity to metabolise sugar. "However, this discovery is classed as a major breakthrough in that it has identified a genetic tendency which causes the disorder." Professor Paul Zimmet, director of the International Diabetes Institute (Reuter, July 2 1992) X Some types of Type II diabetes in human were linked to gene locations in 1992. X @ A connection between a gene and one type of diabetes with implications for hundreds of thousands of Americans was reported in February, 1993. "This is the first clear definition of a genetic cause of Type II diabetes," said Dr. Simon Pilkis, chairman of the Department of Physiology and Biophysics at the Stony Brook Health Sciences Center in New York. "Moreover, it may be one of the largest single-gene disorders described to date." "Tools are now available to screen for gene mutations, and it is only a matter of time before other genes implicated in Type II diabetes are identified," Pilkis said. "We will be able to screen different diabetic populations or the general population for these mutations, which will tell us whether someone has a predisposition to diabetes and what category they fall into." (UPI 02/28/1993) X @ Research has been accumulating on the fattening effect of high levels of insulin during gestation and infancy. High insulin levels are sometimes caused by excessive serum glucose in the mother's blood and leakage of a insulin- antibody pairs across the placenta. Obese individuals X X X X X X X X X X X Adiposity 101 15 3-9-93 X X X almost always exhibit high insulin levels. X @ Impairment of insulin sensitivity precedes both the development of overt hypertension and gain or redistribution of body fat. The concept that insulin sensitivity is low as a result of altered fat distribution has to be reconsidered. (Lancet 1993; 341: 327-31) X X 5.4 Maternal Environment X What one's mother does or eats during or immediately before pregnancy affects one's BMI. X @ Too much carbohydrate during gestation is Not Good. Gestating infants whose blood was highest in insulin 1 (caused by elevated glucose in the mother's blood) were markedly obese by 6 years of age, independent of the mother's weight. This syndrome is thought to be a cause of Pima Indians' high incidence of obesity. (Archives of Disease in Childhood 1990; 65; 1050-2) Offspring of Diabetic Mothers exhibited an unusual pattern of fat growth; the baby is unusually fat at birth (macrosoma), but assumes normal weight at 1 year. Fat growth creeps in over the next several years, and accelerates at year 5 (girls) or 6 (boys). By age 8 both male and female offspring of diabetic mothers are markedly obese and getting fatter, correlating with insulin levels during gestation. (Diabetes, Vol 40, Suppl2, Dec 1991, 121-5) X Mother's insulin is not thought to cross the placenta. However insulin injected into IDDM mothers raises antibodies, and these insulin-antibody pairs do cross the placenta. Once in the fetus, the insulin increases fat deposition, resulting in macrosoma. (NEJM Aug 2 1990 323:5 309-15) X The May 1990 METABOLISM reported that changes in the rat sow's diet during early pregnancy had a permanent effect on pups' lipid metabolism. X "Thus we propose that poor nutrition of the fetus and infant leads to permanent changes of the structure and function of certain organs and tissues. The timing and precise nature of the deficiencies determine the pattern of metabolic and X X __________ X X 1. Measured indirectly by sampling the amniotic fluid. X X X X X X X X X X X X Adiposity 101 16 3-9-93 X X X functional abnormalities seen in later life, including diabetes and hypertension and possibly including some hyperlipidaemias and even insulin resistance. We suggest that poor early development of islets of Langerhans and Beta cells is a major factor in the aetiology of Type 2 diabetes." (Diabetologia 1992 35; 595-601) In some diabetic subjects defective insulin-like molecules constitute up to two thirds of the total concentration of insulin-like molecules in plasma that are measured as "insulin" by normal tests. Measuring the defective molecules as "insulin" can lead to misdiagnosis that a patient is insulin resistant when in fact he is insulin deficient. X @Pigs undernourished from 10 days to 1 year eventually became extremely fat. They had plenty of fat cells at 10 days of age, but these cells were completely empty and did not register by conventional cell counting at 1 year. However, as soon as plentiful food was supplied, the pigs became extremely fat; the longer the period of deprivation the fatter they tended to become. This finding was directly opposed to the view that an excessive number of adipocytes are formed only when overfeeding takes place in infancy. (Proceedings of the Nutrition Society 1992: 51, 353-65) X Mothers who experienced caloric deprivation in a critical portion of pregnancy during the 1944 Netherlands Hungriwinter bore sons 2-3 per cent of which were obese at age 19, more than twice the normal incidence of obesity. X Infant undernutrition caused by smoking may produce similar results. X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Adiposity 101 17 3-9-93 X X X 5.5 Baby's Diet X A Case Western Reserve University study (4P-17) compared rat pups fed a milk-substitute formula (56% of calories from carbohydrates) with mother-fed controls (only 8% of calories from carbohydrates). The formula fed rats became fat. "The results show that alterations in the source of calories rather than the total caloric intake during the suckling period can have specific long-lasting effects on lipid metabolism in adulthood, leading to the development of obesity." X ___________________________________________________________________ |Diet Change | Result in adult | |________________________|_________________________________________| |PW to High Carbohydrate | More prone to hypercholesterolemia | |PW to High Fat | Prevents hypercholesterolemia | |Overnutrition* | Elevated plasma cholesterol and insulin | |Undernutrition* | Obesity | |________________________|_________________________________________| X PW = prematurely weaned *3-10 days after birth (FASEB Journal, June 1990, p. 2606) X @The fattening effect of a high carbohydrate diet at weaning is explained in a review of the influence of diet on the development of adiposity appearing in the 1992 Proceedings of the Nutrition Society. X @ Laboratory reared rat pups fed a high carbohydrate formula have higher serum insulin and increased liver fat synthesis capacity compared with pups fed a high fat formula or reared naturally. Early exposure to a high carbohydrate diet predisposes an increased fat creation capacity in liver and adipose tissues and to the development of obesity later in life. (J Nutr. 123: 373-7, 1993) X Kramer found that breast feeding and delayed introduction of solid food protected against subsequent obesity. @ 95% of the obese had not been breast fed. (J Pediatr 1981 98: 883-7). X Breast-fed infants are leaner than formula-fed infants at 1 year. The formula-fed infants were fatter because energy intake on high carbohydrate formula is higher. (Am J oc Clin Nutr 1993;57:140-5) X These results support the assertion of a Reader's Digest article that breast feeding can "Fat Proof" one's baby (compared to formula feeding). Left unanswered is the question: at what age should the suckling's low carbohydrate X X X X X X X X X X X Adiposity 101 18 3-9-93 X X X diet evolve to the high carbohydrate diet currently favored by diet evangelists? Insulin is the primary drive for the major increase in hepatic and adipose tissue lipogenesis that occurs during the early dynamic phase of obesity; dietary carbohydrates increase insulin levels. X (Please refer to the discussion of adipose cell reversion and replication elsewhere in this document.) X Breast milk contains human Epidermal Growth Factor (EGF) (discussed above), a potent inhibitor of obesity not present in infant formula and cow's milk. X Children need dietary fat to insulate their nerve cells, prevent nerve crosstalk and brain damage. Nw There is concern that infant formula does not provide certain long- chain lipids necessary for good cerebral and retinal development. (Acta Paediatr Scand Suppl 365: 58-67, 1990) X Early exposure to cow's milk and solid foods in infancy increases the risk of diabetes in genetically predisposed babies. (DIABETES Feb 1993: 42: 288-95) X X 6. EFFECTS OF OBESITY X 6.1 Personality Problems X As the causes of obesity become known, obesity is increasingly recognized as a cause of mental health problems rather than the result of mental problems. X Obesity has been historically linked to emotional factors by clinicians and the lay public alike. Early psychiatric studies reinforced the popular perception that psychpathology is common among the overweight and plays an important role in the development of obesity. This notion has been challenged by recent investigations which suggest that psychological disturbances are more likely to be the consequences than the causes of obesity. Emotional difficulties faced by the obese may be largely attributable to an entrenched cultural contempt for the obese and a pervasive preoccupation with thinness. (Annals, New York Academy of Sciences, 1987) X "There appear to be no global personality traits or profiles that are associated with obesity." (Am J of Clinical Nutrition July 1992) X X X X X X X X X X X X X X Adiposity 101 19 3-9-93 X X X 6.2 Health Problems X The correlation between obesity and certain health problems has been widely documented. Joint problems and sleep apnea are generally recognized direct effects of obesity. X The effect of obesity on cardiovascular disease and diabetes is not well understood; both may be markers of basic underlying metabolic derangements. Controversy remains about the true cause and effect. There is no agreement in the scientific community that dieting provides a long term health improvement. X "... even though we like to believe that weight loss in the obese is accompanied by a reduction in the mortality rate, it is important to keep in mind that no intervention study has yet dealt with this issue." (Letter to JAMA from Bouchard, Despres, and Tremblay) X An Aug 5 1990 BBC broadcast reported that the size of a baby relative to the size of the placenta had a greater correlation on adult blood pressure than the combined effects of weight or alcohol consumption. X Some of the correlation between obesity and health problems may be caused by common factors. For instance, DHEA and HGH help the healing process, help the immune system, block autoimmune disease, hyperglycemia, and neoplasia, promote muscle buildup and fat loss. The obese have much lower levels (order of magnitude) of Human Growth Hormone (HGH) and DHEA than normal subjects. Men with abdominal obesity have low testosterone values. Mice obesity genotypes are thought to promote various diseases. If both the obesity and poorer health result from common factors, only correction of the common factors will improve the patient's health outlook. X Even is there is no great health risk from moderate corpulence, endomorphs would still wish for normal body composition simply because being fat in this society is an unmitigated bitch. X Some of the health problems associated with obesity result not from the obesity itself but from the effects of dieting.2 As reported in the 1990 House hearings on the diet X X __________ X X 2. This does not refer to gall bladder and other acute X problems some subjects have with specific diets. Gall X X X X X X X X X X X Adiposity 101 20 3-9-93 X X X industry, studies consistently show an increase in mortality with weight cycling. None have shown an improvement in long term health outcomes from dieting. X Some obesity related health problems are the result of discrimination against obese patients by the medical establishment. Insurance companies discriminate against obese individuals, even those with no history of health problems. Insurance companies are forbidden to test applicants for HIV, a right of privacy not afforded to overweight applicants who are compelled to test and report their weight. X The obese often get substandard medical treatment. In one case, symptoms of allergy induced asthma (post nasal drip) were attributed to obesity for several years, denying the patient effective treatment. Marginally overweight women are humiliated by male doctors. In one case, a surgeon "called the patient a fat bitch" and said "people like this do not deserve to live and that the only exercise she probably got was walking from the kitchen table to the refrigerator." Similar abuse was reported in a 1983 Nova program. It is incumbent of the AMA and regulatory bodies to monitor this abuse and institute corrective measures. X "Some doctors can be as cruel as kids in a playground when faced with a fat patient." (Medical World News, May 1992) X The University of Kentucky have a developed a course designed to correct the attitudes of doctors towards fat people. (IJO 1992 16, 859-868) X X 7. TRADITIONAL TREATMENT X Obesity prevalence estimates are virtually unchanged from the early 1960s, according to the Centers for Disease Control. X As reported in the 1990 House hearings, there is no effective long term treatment for obesity. X X X X X X ____________________________________________________________ X X bladder problems are common in obesity. X X X X X X X X X X X X Adiposity 101 21 3-9-93 X X X 7.1 EXERCISE X The correlation between exercise and thinness is well known and firmly established in cultural and media stereotypes. Victims of obesity are criticized for not engaging in physical activities enjoyed by thin people. Before prescribing an exercise regimen for weight loss, one must consider obesity's effect on ability to exercise and obtain pleasure from such activities. Overweight people, and the more overweight the more of a problem, are limited in the amount of exercise that they can endure. The lower athletic potential of obese individuals generally denies them the satisfaction of athletic success even if they manage to lose weight. Obese individuals may be unable to attain altered states such as "runner's high". These factors pose an alternative explanation for the reported correlations between exercise and thinness. X Individuals vary widely in their metabolic response to exercise. Reduction in body fat percentage varied from 49% to 1% for subjects placed on the same supervided exercise regime. VO2-max (liters/minute, a measure of fitness) change varied from 0% to 14%. The differences in these responses were mostly genetic. (Arteriosclerosis Vol 8, No 4) Mesomorphs' favorable responses to exercise programs tend not to accrue to endomorphs. X @ Even after prolonged training program (6 mo), no pronounced effect on body fat was seen, whereas nonobese controls reduced their adipose deposit. (Metabolism 26:319, 1977) Obese subjects with fewer fat cells decreased in weight whereas patients suffering from severe obesity and an elevated number of fat cells even gained weight. (Metabolism 28:650, 1979) X The fattening effects of exercise in hyperphagic obese may be explained by a post exercise peripheral tissue insulin resistance. (Journal of Clinical Endocrinology and Metabolism 1989 68:2 438-45) X "The current low physical activity is possibly a result rather than a cause of higher body weight in old age." (Int J of Obesity, 1992, p. 199) X An Italian study found correlations between the children's BMI and their fathers' BMI. A significant correlation between BMI and exercise was documented only in the group of girls. Heavier boys didn't get that way from lack of exercise. X A study conducted by the Physical Education Association X X X X X X X X X X X Adiposity 101 22 3-9-93 X X X Research Centre and Schools of Education and Postgraduate Medicine, University of Exeter published in the July 28 1990 British Medical Journal found "No significant relation was detected between the level of habitual activity and skinfold thickness in either sex. Similarly, the children classified as overweight were not significantly less active than children who were not overweight." X A Charlottsville VA study in the 1991 International Journal of Obesity reported: "Obese and nonobese children had similar levels of physical activity and attitudes toward activity" X "Although many researchers and the lay press have argued that physical inactivity in children is strongly related to obesity and weight gain, the research is contradictory. ... One should have expected that, in the better done epidemiological studies such as in Tecumseh or in Finland, a strong consistent relationship should be found between activity and obesity. This was not found to be the case." (p. 563, Progress in Obesity Research 1990) X A Minnesota Heart Health Program study noted a significant increase in obesity from 1980 to 1987. The data suggest that change in energy intake, fat intake, exercise, or cessation of smoking were not responsible for this increase. X In a UC Davis study, a high level of exercise (marathon training) caused a modest weight loss, averaging 7 pounds when a permanent plateau was reached at 8 weeks. X In a three month Swedish study of 60 minute exercise to 80 per cent of maximum capacity, obese men lost 2.9 kg of body fat, an amount of "borderline significance". Obese women did not lose fat except for some of the most obese subjects. (International Journal of Obesity 1991, 15, 75-81) X Other studies did not show an increase in weight loss when aerobic and anerobic exercise was added to VLCD (Very Low Calorie Diet) and other diet programs. ("Lean Body Mass, Exercise and VLCD", International Journal of Obesity (1989), 13 (suppl. 2), 17-25.) X @"However, the addition of exercise does not affect total body mass loss. A net loss of FFM was observed in all groups, regardless of exercise modality [including resistance strength training]." (American Journal of Clinical Nutrition 1992: 11;2:152-8) X Several years ago it was widely reported that working out left one with an "exercise afterglow" for up to 12 hours, X X X X X X X X X X X Adiposity 101 23 3-9-93 X X X during which body metabolism remained at least slightly elevated. More recent studies have shown that this effect requires a level of exercise attainable only by highly trained athletes. Moderate exercise does not increase the metabolism of obese subjects. X Exercise induces increased growth hormone levels in lean subjects. The obese do not release growth hormone in response to moderate exercise. @ In obese subjects, fenfluramine partially restores GH responsiveness to arginine but not growth hormone releasing hormone; fenfluramne may or may not restore GH responsiveness to exercise. Experimentation to determine the optimum timing between fenfluramine doses and exercise is needed. X Keithf.Lynch@f8.n135.z1.fidonet.org has reported reading that individuals over 20% overweight should not exceed a pulse rate of 0.6 * (220 minus age). This guideline precludes robust exercise for the obese. X Exercise is generally credited with reducing cholesterol and triglyceride levels. However, as reported in the October 10 1990 Journal of the American Medical Association, it may not work for the overweight. A 28 year old mildly overweight man went to a fitness center to begin an exercise program with the goal of losing 10 pounds. This man had recently had a physical in which the "usual values were normal". His fitness counselor put him on a exercise bike, a rowing machine, and then fast walking on treadmill for a total of thirty minutes of vigorous exercise. The next morning he couldn't get out of bed without help. On his next visit to the fitness center, the fitness counselor advised him to repeat the exercise program, which he did. The following day he was admitted to hospital with kidney failure. Emergency procedures restored his kidney function after 11 days. A long time later his blood pressure remains elevated, and he complains of headache, edema, and sleep problems. His triglyceride and cholesterol levels are also elevated. X A UC Davis study reports that rats subjected to an exercise regime reach plasma triglyceride and adipose LPL levels greater than sedentary controls within 84 hours of exercise termination. X @ The lean subjects had marked changes in lactate, pyruvate, FFA, and catecholamines, consistent with the need for rapid mobilization, uptake, and utilization of carbohydrate and fet-derived fuels. The responses of the obese subjects differed in insulin, FFA, glycerol, and, surprisingly, epinephrine. The postexercise hyperglycemic X X X X X X X X X X X Adiposity 101 24 3-9-93 X X X hyperinsulinemic state was more intense in the obese subjects and associated with higher plasma FFA and blood glycerol levels. After exercise, as in many other situations, obese subjects have insulin resistance. (J of Clin Endocrinology and Metabolism 1989 68:2 438-45) X An alarming study published in the International Journal of Obesity (1992;16;519-527) reported Short-term exercise can reduce weight and fat gain in obese humans and animals. However, the beneficial effects are not long-lasting. After cessation of exercise, there was no difference in body weight, fat mass, and percentage body fat between exercised and sedentary OB rats. Unfortunately, the exercised rats had a significantly higher amount of internal fat and internal:subcutaneous fat ratio. Increased insulin sensitivity produced by exercise training has been reported previously, and this may be the cause of rapid fat gain; the same effect has been documented after dieting. Fat cell NUMBERS in some areas were actually increased compared to the sedentary rats. This increase in adiposity may pose health risks. X Severely overweight subjects showed a 50 per cent impairment in FFA [Free Fatty Acid] mobilization in response to prolonged moderate exercise (level walking). This energy shortfall was made good at the expense of a drop in blood sugar (causing tiredness) and increase in lactate plasma (aching muscles). This represents a metabolic limitation on exercise by the obese. (See "fast fibres" above.) (1983 International Journal of Obesity pp 221-229.) X "We tend to be thinner when we are young not because we consume fewer calories, but because we metabolize glucose more efficiently." (Valdimie Anisimov M.D., p. 26, October 1990 Omni) X Contrary to the claims of Cable TV ads, there is no clinical evidence of spot reducing from any exercise. X Unlike diets, exercise-only weight loss programs have not been reported to result in weight rebound. The small amount of weight loss may account for this. X Exercise induced weight loss is temporary, but will be maintained as long as the intensity of exercise is maintained. X The fragile bones of an old woman may develop early in a female athlete who pushes too hard to stay skinny and excel in her sport. These women have developed eating disorders, pushed their endurance workouts too hard, or both -- and X X X X X X X X X X X Adiposity 101 25 3-9-93 X X X have ceased to menstruate. X "Exercise can produce a modest gain of Lean Body Mass (LBM) and loss of fat in weight-stable individuals, but it is important to realize that if much weight is lost during exercise there is a risk of erosion of the LBM. Data from both human and animal experiments show that exercise cannot conserve lean weight in the face of significant energy deficit" (Lead Review Article, Nutrition Reviews 50;6 June 92) X High dropout rates and the low rates of weight loss (0.14 kg/week) in exercise studies by Brownell and Stunkard indicate the difficulties encountered in the use of exercise for weight control. Long-term data are not available about the value of exercise in obesity. X "1) energy cost of exercise is minimal, 2) effects on thermic of food are negligible ... exercise may not prevent, and may even increase the fall of metabolic rate" (Am J of Clinical Nut, Feb 1992) X It is hoped that eventual progress in the treatment and prevention of obesity will allow more people to enjoy the pursuit of more active pleasures. X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Adiposity 101 26 3-9-93 X X X 7.2 DIETS X "The high prevalence of obesity in affluent societies, coupled with an increasingly lean aesthetic ideal, has resulted in unprecedented rates of dieting." (International Journal of Obesity 1990, 14, 373-383) X Dieting is a natural idea given the obvious, if temporary, effects of famines and religious fasts. Energy deprivation as a method of obesity treatment had changed little since Greek antiquity. X A supposition behind reducing diets is the conventional wisdom that overeating by the obese upsets the natural weight regulation enjoyed by the majority of humans. X In distinction to the commonly accepted stereotype, research shows that the obese do not eat more than their lean counterparts. In addition, research has failed to demonstrate significant defect in obese subjects' hunger/satiety response to eating compared to that of lean subjects. (Int J of Obesity 1990,14: 219-33) X @There was no significant difference in energy intake at three months of age between babies of fat and thin mothers. The findings can be compared with those in the strains of genetically obese rodents used as models of human obesity, in which the development of fatness precedes any increase of energy intake. "Our findings suggest that the most appropriate approach to preventing obesity in susceptible infants may be to increase their energy expenditure, rather than decrease their energy intake." (NEJM Feb 25 1988) X "Most people believe that the obese eat much more than other people, that this is the cause of their obesity, and that they could become lean and remain slender by eating "normal" amounts of food. This belief is particularly resistant to change since it was the accepted scientific position for many years and since there is little opportunity for spontaneous revision of generalizations about behaviors that show such great variability. Even if it were possible for the average person to make accurate observations of the habitual intakes of fat and lean acquaintances, and to recall them without distortion, it would be hard to perform the required arithmetic averaging operation in one's mind. Instead, it seems, people recall the behaviors that fit their preconceptions, remembering the large intakes of some obese people, while forgetting the modest intakes of others. X In fact, the best data available suggest that the obese, as a group, eat no more than the lean." (American J of Clinical X X X X X X X X X X X Adiposity 101 27 3-9-93 X X X Nutrition 33: Feb 1980 p. 465) X @A number of studies compare the ratio of energy intake to some arbitrary measure of body parameters. Not surprisingly, the choice of body parameter to use in this "normalization" controls the outcome of the "study". Some studies use fat free mass (whose definition and measurement is itself controversial) for this normalization, ignoring actual body weight. Such an intellectual maneuver should be reassuring to fat people who have been warned that their fat strains their body. "There should be no doubt that simply walking, climbing stairs, or pumping blood through all of the excess tissue is a form of exercise." (IJO 1989;13;s2 17) A study of energy requirements of dieting men found that replacing lost body weight with equivalent lead weights reduced the fall in energy expenditure by more than 50%. Adipose tissue is more active than either lead weights or many components of FFM, so normalizations based on other than total weight must be regarded with cynicism. X "Canadian researchers who studied the eating patterns of 80 SHAR_EOF true || echo 'restore of adiposity.101 failed' fi echo 'End of part 1' echo 'File adiposity.101 is continued in part 2' echo 2 > _shar_seq_.tmp exit 0 -- ======================================================================= ú Subject: Adiposity 101 2/4 women between the ages of 30 and 38 found that smaller eaters weighed an average of 10 pounds more than their larger-eating counterparts. ... Small eaters in the study had an average of 22 per cent more body fat than the large eaters." (F1, The Oregonian, 2/14/91) X "Mean energy intakes were not significantly different between the lean and fat individuals. ... It does not appear that the obesity is caused by overeating." (Journal of the American Dietetic Association, 11/86) X "Less expected was the raised SDS [obesity] among those consuming recommended caloric intakes. This indicates that obese children have a higher, probably genetically determined, weight level than the non-obese population." (The Lancet, Aug 26 1989) X "Members of dietetic associations do not appear to differ from the general public with regard to weight control. Knowledge is obviously not enough for the health professional or their clientele." (American Journal of Clinical Nutrition, 6/92) X "We found no significant relationship between obesity and the items documenting food consumption" (Int J of Obesity 1992, 16, 565-572) X "The modest caloric intake of these men and the lack of correlation per cent body fat and total calories suggest that calorie differences are not the major causes of obesity X X X X X X X X X X X Adiposity 101 28 3-9-93 X X X in these men." (American Journal of Clinical Nutrition, 6/86) X "There was no relationship between energy intake and adiposity" (American Journal of Clinical Nutrition, 9/90) X "caloric intake per unit of lean body mass was constant regardless of the degree of obesity" (Journal of the American Dietetic Association, 2/92) X "Comparisons of obese adolescents to normal peers have demonstrated comparable energy intake and nutrient distribution." (Journal of School Health 2/92) X @"No significant G effect was found for daily energy intake, daily intake per kg body weight, and for any of the nutrient intake (g/day)." (Recent Advances in Obesity Research: V 16-25) X "Rural subjects were leaner, suffered less from diabetes and hypertension, and generally had higher cholesterol levels." (J of the American College of Nutrition, 1992, p 283-) X "Studies on habitual food intake have failed to observe any consistent differences between obese and lean subjects." (p. 80, Obesity and Leanness - Basic Aspects) X "Energy intake was inversely related to the 12-yr incidence of myocardial infarction. The correlation was independent of age, obesity, smoking, serum cholesterol, triglycerides, diabetes, systolic blood pressure, and physical activity. No correlation was found between dietary intake and incidence of stroke or overall mortality, nor was any correlation found between end-points and intake of fish, energy percentage from fat, protein, and carbohydrates." (Am J of Clinical Nutrition, Oct 1986) X "the mean intake by the overweight subjects was less than that of the controls. ... Food intake has declined over the past decade when body weight and presumably fat stores have, on average, increased. From the epidemiologic data, it appears that increased caloric intake in the population can not explain the positive energy balance [obesity] observed in adult life in the United States, the Netherlands, or Sweden. ("Diet and Health: Implications for reducing chronic disease risk"; Committee on Diet and Health Food and Nutrition Board Commission on Life Sciences, National Research Council; National Academy Council, Washington D.C. 1989.) X "the following aspects of weight are myths rather than X X X X X X X X X X X Adiposity 101 29 3-9-93 X X X reality: (a) There are objective definitions of obesity; (b) obesity is prevalent among women; (c) obese people take in more calories than the nonobese; (d) dieting is an effective way to reduce weight; (e) obesity is related to poor physical health." (J of Psychology, Jan 1990) X "Discrepant findings in the literature concerning relationships between obesity and energy intake may be explained by reporting error and by the relative lean mass of obese vs nonobese women but not by systematic underreporting unique to obese subjects." (Am J of Clinical Nutrition Feb 1989) X "Body mass index did not correlate with either current energy intake or energy expenditure. Smokers and drinkers had lower age-adjusted levels than non-smokers and abstainers. CONCLUSIONS> Since the excess body mass index levels associated with low socioeconomic status in women could not be explained after controlling for adverse health behaviors, further epidemiologic study of risk factors for obesity in Black women is recommended." (American J of Public Health, Jun 1992) X @We believe that eating behavior is more likely a secondary phenomenon, rather than a primary event in its etiology. The growing understanding of cellular physiology and biochemical genetics coupled with the repeated failures of dietary and behavioral forms of treatment speak for obesity being a disease of unknown etiology in which food intake is but link in a complex, causal chain. (Western Journal of Medicine Oct 1990; 153;421-428) X Various techniques have been used to enforce diets, including appetite reducing drugs and surgical modification of the digestive system (balloons, staples, bypass, etc.). None of these has proven to improve the basic dynamics of the diet. Many have serious side effects beyond that of the diet itself, including immune system problems caused by low cholesterol levels. X Lean and obese female Zucker rats were intermittently semistarved during their first 32 weeks of life, then fed ad libitum. "long-term caloric restriction during development appears to be effective in suppressing dietary obesity in animals that do not have a genetic predisposition to obesity, it appears not to be effective in animals that have a genetic predisposition to obesity." X X X X X X X X X X X X X Adiposity 101 30 3-9-93 X X X 7.3 SLOW vs RAPID Weight Loss X Controversy abounds about the efficacy of rapid vs slow weight loss. Many studies addressing this issue are flawed by sample selection problems. Slightly overweight subjects on mild diets do not reagain as much weight as massively overweight subjects placed on more stringent diets. X Results are different when subject selection is randomized. Subjects on 1200 calorie and 800 calorie VLCD type diets had the same ratio of fat loss to lean tissue loss. The major effect of slowing the rate of weight loss was prolongation of the need to diet. Diet induced metabolic slowdown was a direct function of the amount of weight lost and nothing else. (International Journal of Obesity 1989, pp 179-181) X It does not appear that fasts are more difficult than moderate diets for many patients; indeed, many report considerably less hunger and a sense of well being. (American J of Clinical Nutrition 33: Feb 1980 p. 468) X X 7.4 BEHAVIOR MODIFICATION X "The third aspect of treatment is maintenance of a stable caloric intake. It would seem that if anything has been clearly established in the research on behavioral treatment of obesity, it is that weight maintenance can be achieved with this therapy. The shortcoming of behavioral programs has been the small losses achieved; the record of maintenance is, by contrast, impressive. ... It should be noted that behavioral programs do not really have to contend with the problem of redeeding since the losses are usually quite small and achieved with minimal restriction." (American J of Clinical Nutrition 33: Feb 1980 p. 469) X X 7.5 Diet Side Effects X A common result of reducing diets is weight regain. 95 per cent regain all the lost weight within 5 years. X A Swiss study compared various diets' effects on weight regain. Low caloric intake induces an adaptive increase in metabolic efficiency. Its persistence after slimming is an important factor in the ease with which the obese condition is regained. After body fat is reduced by feeding a low calorie diet, refeeding a similar caloric intake as weight- matched controls over a 2 week period results in a 15-20% lower energy expenditure, 3-fold increase in the rate of fat deposition, and a doubling of energetic efficiency. X X X X X X X X X X X Adiposity 101 31 3-9-93 X X X Isocaloric diets varying in protein content (8-40%), fat content (5-55%), differing fat types, and carbohydrate types were tested in search of an effective weight maintenance regimen. The elevated energetic efficiency during refeeding was partially reduced by low protein diets. Weight rebound was unaffected by the type of fat or the type of carbohydrate. Provided the diet provided adequate protein and did not exceed 35 per cent fat, no diet, including low fat, had an impact on the post weight loss reduction in energy expenditure that facilitates weight rebound. X An Italian study (1P-115) indicates obese subjects with high insulin and triglyceride levels are more resistant to diets. X Dieting does not reduce the number of fat cells, even in subjects carrying ten times the normal number. In fact dieting can increase the number of fat cells. X In a Swiss study of lean and obese rats, reduced energy expenditure (EE) of obese rats with limited caloric intake resulted mostly from metabolic slowdown not related to reduction in lean body mass or activity levels. This metabolic slowdown continued after the obese rats returned to normal caloric intake (eating the same as lean rats) and regained the weight they had lost. (International Journal of Obesity 1991, 15, 7-16) Corticosterone induced inhibition of thermogenesis is suspected. X Diet induced metabolic slowdown has two aspects: Resting Metabolism Rate (RMR) and Diet Induced Thermogenesis (DIT)/Thermic Effect of Food (TEF). X The definitions and methodology for measuring and interpreting data on metabolism rates are not standardized, and it is no surprise that studies on diet induced decline in RMR are highly controversial. Furthermore, RMR studies may not distinguish between subjects in the depressed energy balance of weight suppression maintenance and subjects regaining lost weight. Until this these flaws are satisfactorily resolved, studies of RMR must be approached with the greatest of caution. X @A recent paper in the American Journal of Clinical Nutrition concluded that conflicting results that did not detect diet induced drop in RMR might be due to defects in their body composition assessment methods. Some studies that did not report diet induced metabolic slowdown were made on subjects who had already started weight regain, and were thus at a higher RMR than when losing or maintaining lower weight. "Further studies are required to investigate mechanisms of metabolic adaptation to hypocaloric diets X X X X X X X X X X X Adiposity 101 32 3-9-93 X X X because the phenomenon itself appears to be an established fact." Studies of DIT/TEF consistently report a metabolic slowdown with dieting. X @Studies that do not report diet induced metabolic slowdown may be measuring the post-diet metabolism while subjects are regaining weight. One study that did not make this mistake recorded a 27 per cent drop in weight stable caloric intake from 28.9 to 21.5 kcal/kg per day as the 175-270 pound subjects lost a modest 20 pounds. (Journal of Clinical Endocrinology & Metabolism 1987) X @ Past studies that support or deny the existence of an adaptive metabolic component contributing to the low EE (metabolic slowdown) during chronic underfeeding have been inconclusive in experimental designs and data interpretations. The magnitude of the fall in EE during low calorie intake is similar to that recently shown to occur after slimming of grossly obese mice, as well as that reported in post-obese human subjects maintaining body weight on a restricted intake of food. This increase in metabolic efficiency may be important in the rapid relapse of obesity after slimming. (IJO 1993 17, 115-23) X @ "Low and very low calorie diets have a common aim: to provoke a negative energy balance in order to diminish energy stored in adipose tissue. The purpose of people using them is less esoteric: to lose weight and to provoke morphological changes with the hope that this in turn will improve their health, their looks and their sexual status. As a rule, the aim succeeds and the purpose fails. ... Adaptative changes in energy expenditure are the most intriguing feature. ... When the level of T3 is artifically maintained by an adequate addition of T3, the nitrogen balance is not modified and the BMR remains at its baseline level." (IJO 1993 17 (Suppl 1) S13-6) X @ "Adaptive changes in metabolic rate in response to low caloric intake relies on complex and highly redundant readjustments of the thermoregulatory system including both behavioral and physiological regulations, and acting on both heat loss and heat production. It contributes to the rapid replenishment of fat stores as soon as an adequate amount becomes available again. It thus has a survival value in subsistence societies societies. In affluent societies it is a source of despair for the obese and of fortune for the authors of slimming programs." (IJO 1993 17 (Suppl 1) S3-S8) X @Dieting enhances or creates a fattening effect of some drugs. Propanolol reduced the metabolic energy expenditure of reduced-obese women but not that of nonobese women. (Am X X X X X X X X X X X Adiposity 101 33 3-9-93 X X X J clin Nutr 1992;56;662) X Many dieters experience unpleasant side effects. The severity of side effects tends to be less for younger subjects and those whose weight gain was caused by overeating. X X + Dry mouth X X + Sleep Disruptions (difficulty falling asleep, excessive X sleepiness, disturbed sleep, vivid dreams) X X + @ Substantial impairment of cognitive performance, 30 X per cent and worse accuracy reduction on a standardized X cognitive task. The cognitive impairment was related to X the degree of weight loss. Heart rate immediately X before and after testing was lowest in the current X dieters with high weight loss. Lowered heart rate is X typical of a chronic state of undernutrition. X (Proceedings of the Nutrition Society 1992: 51, 343-51) X X + @ Aggression and suicide. Monkeys on a low fat diet X were significantly more aggressive than were controls on X a normal diet. In middle-aged humans, there was a X significant increase in mortality due to suicides or X violence: compared with control groups, the treated X groups had 29 more deaths from suicide, homicide, and X accident. Adolescents are thought to be more X susceptible to these effects. (Lancet 339: March 21 X 1992, p 727) X X + Cold Intolerance. "Cold intolerance is a significant X problem aggravated by dieting in morbid obesity." X X + Lack of energy. X X + Menstrual Difficulties X X + Yest Infections X X + Fluid Retention X X + Low pulse rate and blood pressure. One symptom of low X blood pressure from metabolic slowdown is dizziness when X abruptly arising from a chair. X X Normally, low resting pulse rate and blood pressure X indicate a healthy body. Dieters and their doctors X rejoice when energy deprivation lowers their high blood X pressure and heart rate readings. Unfortunately, these X lower numbers do not imply better health when lower X X X X X X X X X X X Adiposity 101 34 3-9-93 X X X X pulse rate and blood pressure result from diet induced X metabolic slowdown and not cardiovascular improvement. X X Lowered heart rate is typical of a chronic state of X undernutrition. (Keys et al, The Biology of Human X Starvation) X X + Constipation X X + Stomach Distress X X + Hair loss X X + Ridged Nails (low fat diet vitamin or mineral X deficiency) X X + Dizzy spells X X + Weakness X X + Headaches (mostly women) X X + Hot flashes X X + Depression (as measured in standardized tests). X X + Collagen generation as low as 5% of normal. (Collagen X is the major protein of all connective tissues, a X shortage of which is believed to cause wrinkles, etc. X Collagen production is necessary for wound healing and X normal growth.) This might explain the degraded X appearance seen in some dieters. X X + Memory problems A London conference held by the British X Psychological Society heard that people who fight the X flab can become forgetful and have difficulty performing X simple tasks. Until now scientists had thought only X people with anorexia nervosa, the slimmer's disease, X suffered mental impairment as a result of chronic X undernourishment. X Diet induced metabolic changes include an increase in lipoprotein lipase (LPL), an enzyme that stores fat in fat cells. LPL levels drop during the first few weeks of dieting. Depending on the study, LPL levels remained normal or depressed for some time. Subjects with BMI < 35 or who lost less than 12% of their initial body weight did not show marked increases in LPL. But in the more obese subjects, LPL rose to 25 times normal, and remain elevated for at least 6 months. The fatter the person was to begin with, the more of the fattening enzyme they produced after weight X X X X X X X X X X X Adiposity 101 35 3-9-93 X X X loss. Kern's paper sheds insight on many issues related to the varied outcomes different people have to diet cycling. (New England Journal of Medicine, Vol. 322 No. 15, Apr 12 1990) X (See also: Metabolism: Clinical and Experimental, Jul 1987) X Adipose cells have different receptors for storing and releasing fat. Weight loss diets worsen the ratio of fat cell receptors, promoting weight regain. X A common side effect of dieting is the loss of lean tissue. Some lean tissue loss is considered acceptable because the lighter body's muscle needs are less. The low levels of growth hormone characteristic of obese persons impedes the body's regeneration of lean tissue. This may be a factor in the adverse health effects of repeated weight loss. Human Growth Hormone injections increase fat loss and drastically reduce lean tissue loss during dietary restriction. (J of Clinical Endocrinology and Metabolism, 1987, p. 878) X Dieters need drugs to suppress the excessive amounts of LPL, glucocorticoids, and runaway fat cell proliferation triggered by energy deprivation and diet cycling. The experimental drug LY79771 has reduced post diet weight rebound in rats by about 20 per cent. X Another side effect of dieting is bloating. A dieter with stomach distress may think she is overeating when in fact she is nearly experiencing slight symptoms of bloating caused by dieting. Bloating is rarely discussed in diet books, but is familiar to doctors working with famine victims. Extreme cases of bloating with distended stomachs are sometimes seen in TV documentaries of famine, the ultimate hypocaloric diet. X A good guide to diet side effects (with recommendations for some) may be found in Appendix C of "The new, revolutionary Underburner's Diet, How to Rid Your Body of Excess Fat Forever" by Barbara Edelstein M.D. (c. 1987) X An important side effect of caloric restriction is the binging rebound. Diet evangelists talk of food as a substitute for love and other putative psychological upsets being a cause of binging. More commonly binging is a natural biological response to starving, and rarely appears in non dieting individuals. X Binging is part of the body's "set point" servo system response to energy shortfall. Animal and human deprivation studies consistently demonstrate a period of markedly X X X X X X X X X X X Adiposity 101 36 3-9-93 X X X increased caloric input that tapers off as the body recovers from starvation. In one study of binging, the frequency of binges and the number of calories eaten approximated the diet's caloric deprivation, resulting in a near normal overall energy balance. Diet induced binging may be important in the onset of adipocyte hyperplasia associated with diet cycling. X Traditional wisdom on weight regulation holds that overeating and binging lead to obesity. In fact the reverse relationship exists, with dieting causing eating disorders. "dieting, rather than binging, is the disorder professionals should be attempting to cure." (Journal of School Health, Aug 1989) X X 7.5.1 Eat More to Lose Fat Individuals unable to build muscle or lose fat on an aggressive diet/exercise regimen have reported success when they increase their energy intake. The number of such anecdotal reports reports suggests that a metabolic starvation protection mechanism present in some individuals was interfering with the weight loss one would normally expect from energy starvation. It may be relevant that studies of pre-obese children indicate lower energy intake (they eat less) than lean counterparts. It has also been reported that some women cannot reduce their "love handles" except when lactating. X X 7.6 Diet Cycling X For 95 per cent of dieters, starvation is not a normal state, and, unfortunately, neither is the associated weight loss. Many repeatedly attempt to shed their unwanted poundage. X Many overweight people complain that dieting cycles cause net weight gain. They report excessive but relatively stable weight, except during dieting and subsequent weight regain "with interest". X On the surface, animal studies of weight cycling are contradictory, but there does seem to be a unifying concept; diet perturbations increase the body's resistance to future perturbations in the same direction. X When obesity is forced by overeating, cycles of weight fluctuation do not increase fatness. When rats are dieted below their set point, weight cycled rats regained weight more rapidly, regained more weight, but ate no more food than non cycled rats. (Int J of Obes; V12; N6) X X X X X X X X X X X Adiposity 101 37 3-9-93 X X X In humans, weight rebound induced by diet cycling is clinically used to add fat to underweight patients who cannot to gain weight by overeating. X In "Variability of Body Weight and Health Outcomes in the Framingham Population", subjects with larger weight fluctuations had markedly higher BMIs and, what's worse, a higher slope of BMI (BMI/year). (N Engl J Med 1991; 324; 1839-44) A study of workers at Western Electric's Hawthorne Works in Chicago also reported higher BMI in weight cycling men. (Hamm et al. Large fluctuations in body weight during young adulthood and 25-yr risk of coronary death in men. American Journal of Epidemiology 1989, 129:312-318) X In a 1986 Dutch study, men who experienced many life events in a short period showed a gain in body mass. A year later this weight gain had disappeared in almost all subgroups of these men. The exception was the subgroup that tried to lose weight by dieting; those who dieted gained yet more weight. (International Journal of Obesity (1988), 12, 29- 39.) X "We have compared the body composition of obese women who only once lost no more than 10 kg, with a similar group of women who have had two or more cycles of weight loss and regain of more than 10kg. All weight losses were obtained on energy restriction by conventional diets. This retrospective study clearly demonstrates that the `dieters' had significantly lower lean body mass and more fat per kg body weight than non-dieters." (International Journal of Obesity (1989) 13 (suppl.2), 27-31) X In a landmark study of the dieting loss-regain cycle, Drenick et al (1964; JAMA 187:100-105) and Johnson and Drenick (1977; Arch Intern Med 137:1381-1382) placed subjects on total fasts. As with other types of diets, subjects with childhood onset obesity had the most trouble (poor weight loss, side effects) with the fast. At the conclusion of the fast, most of these patients maintained their weight loss for about a year. Half the subjects regained all their weight within two or three years, and almost all had regained their weight by 9 years. Patients with adult-onset and childhood-onset obesity gained weight at the same rate. Regain beyond original admission weight was more common among the childhood-onset obese (42%) than adult-onset obese (26%). Eighty per cent developed diabetes; half of these cases were severe. X Patients at a weight loss clinic lost 2.1 pounds a week on the second bout of dieting compared with 3.1 pounds per week the first time. This pattern also held true for a group of X X X X X X X X X X X Adiposity 101 38 3-9-93 X X X hospital inpatients whose food intake was carefully controlled. X Obese rats took 21 days to lose their excess weight during their first cycle of food restriction, but took 46 days on the second cycle. The cycles animals showed significant increases in food efficiency (weight gain/calorie) in the second cycle. (Physiol Behav 1986;38;459-64) X Bulemic patients with an average weight cycling of 17 kg had significantly lower metabolism than age, height, and weight matched controls. (Arch Gen Psychiatry 1990 47:144-8) X Diet evangelists cite a number of studies which found no serious bad effects from weight cycling. In one, a short term study of high school wrestlers who diet to "make weight" for matches reported that weight and metabolism returned to normal after the wrestling season. No long term followup was performed on these athletic mesomorphs who only lost a small amount of weight for very short periods. These elite athletes never met several of the conditions that trigger lipoprotein lipase (LPL, the "fattening hormone") overproduction in real world dieters. @Subsequent studies have not noted impaired metabolism in the wrestlers who "dieted" to make weight. An incidental, but critical, finding of one investigation, was that in the minds of these athletes dehydration and dieting were synonymous. Their use of the word "diet" is in association with weight loss, not food restriction. Their "diets" lasted but two days, and only a few restricted food intake during this period. (Medicine and Science in Sports and Exercise, 1992; 1270-5) X Diet evangelists are quick to assert that since the diets they recommend differ in one detail or another from the fasts used by Drenick et al, their diets will not provoke the same horrific long term results. There are few controlled studies comparing the safety and effectiveness of different types of diets, but those that have been made found no advantage to slowing the rate of weight loss. X Experiments show that fat cells taken from massively obese subjects have much greater mitogenic (spontaneous cell replication) activity than cells taken from lean subjects. "When mature fat cells from massively obese persons give up their fat and revert in culture to forms similar to preadipocytes, they replicate significantly more rapidly than analogous cells from the lean. The reverted cells, therefore, retain the 'memory of their roots', indicating an inherent property of these cells." Prolonged nutrient energy restriction would lead to reversion of mature fat cells. This process would be increased by regular exercise. When X X X X X X X X X X X Adiposity 101 39 3-9-93 X X X the subject refeeds, the inherited program for excessive replication and differentiation creates even more fat cells. Thus, each diet cycle would lead to an even greater number of mature (large) fat cells, resulting in stepwise progression of massive obesity. (International Journal of Obesity, 1990, 14, 187-192) X Mature (full) fat cells cannot replicate, but Sugihara has suggested that mature fat cells that have released their triglycerol as a result of dieting regain cell division ability. (Journal of Lipid Research 28, 1038-1045) X The data of Bjorntorp and Sjostrom (METABOLISM V20;7;703) show a greater than 10 per cent increase in fat cell numbers from a single diet/partial regain cycle in subjects with many fat cells. Alarmingly, fat cell numbers increased both during dieting (5%) and again during regain (5%). Subjects with fewer fat cells (normal range) did not experience this increase in fat cell numbers. X A paper appearing in The American Journal of Clinical Nutrition found "all three measures (of weight cycling) were significantly related to BMI (P < 0.01)." (Am J Clin Nutr 1992;55;641-4) X @In "Weight cycling: the experience of human dieters", Blackburn et al found a metabolic effect of weight cycling, with slower rates of weight loss on a second diet. The Wadden/Optifast study on diet cycling found a statistically significant correlation between dieting history and weight, BMI, fat mass, waist size, and hip size. The Wadden/Optifast study attempted to refute the Blackburn study by reporting that high diet cyclers lost weight as rapidly as low cyclers. Unfortunately, the high cyclers had three times the excess fat of low cyclers. Normally weight loss on a diet is strongly correlated with initial fatness, but Wadden's high cyclers, with three times the excess weight, lost about the same as the much thinner low cyclers. With half of their excess fat still remaining, Wadden's high cyclers reached a plateau and stopped losing weight on a 1000 calorie diet. (Am J Clin Nutr 1992;56;203S-8S) X The Framingham study also found weight cyclers to be much fatter. X To add injury to insult, diet cycling may be bad for one's health. Weight cycling by dietary means may have a role in the development of chronic disease. X A study by Jeffrey, Wing, and French published in the American Journal of Clinical Nutrition "adjusted" (fudged) X X X X X X X X X X X Adiposity 101 40 3-9-93 X X X the health risk data to "account" for the increased fatness of the diet cyclers. @This adjustment is barely mentioned and never justified in the paper. This adjustment is unwarranted in light of the observation that "without effort to diet, weight changes tend to be small over long periods of time" (Western Journal of Medicine Oct 1990; 153;421) Adjusting for current weight begs the question that diet cycling increases obesity. Applicants experiencing negative health outcomes associated with diet cycling were excluded from the study. As an alternative to such exercises in manipulation, adjusting for weight history before the subjects' first diet would be credible. X This and other studies that "adjusted" for weight gain did not report adverse results of diet cycling besides those commonly attributed to the excess weight from diet cycling. These negative studies are discussed in "Variability of Body Weight and Health Outcomes in the Framingham Population" by Lissner et al. With a cohort of 5127 and more detailed medical records, the Lissner study of the Framingham population supersedes the earlier, smaller, and more idiosyncratic studies. X Diet evangelists have attacked these studies as bitterly as the Tobacco Institute attacks studies linking smoking and disease. Diet evangelists insist that unknown factors other than dieting may have been responsible for these weight fluctuations. (Diet evangelists have yet to suggest any credible alternative explanations for these weight cycles.) A careful reading of these papers will, however, reveal that precisely these concerns were carefully considered and resolved during the study. Finally, this paper's author raised this question with one of the Framingham study investigators in July 1992. He was confident that any cause of weight cycling other than yo-yo dieting widespread enough to affect the Framingham data would have been common knowledge to the doctors of Framingham, who would have diagnosed and treated any such conditions. X @``A big surprise at the NIH meeting was a collection of of epidemiologic studies contradicting the conventional wisdom that extra fat shortens lives. David F. Williamson, Ph.D., an epidemiologist in the division of nutrition of the Centers for Disease Control, Atlanta, said that what "made people sit up and take notice" were 15 studies observing trends among several hundreds of thousands of people, all pointing to the possibility that dieting -- not being fat -- may increase a person's relative mortality risk about 1.5 to 2.5 times. "I was surprised by the consistency of the data," Dr. Williamson said. Another issue that "struck a number of us" was the strong relationship between weight X X X X X X X X X X X Adiposity 101 41 3-9-93 X X X loss and cardiovascular mortality, he said.'' (Medical World News, May 1992) X The heart is not spared from the catabolic effects of undernutrition, but is subject to the same degree of weight loss as skeletal muscle. @Current data suggest the duration and level of caloric restriction are the main risk factors for fatal arrhythmic events. A very low calorie diet probably should not be combined with strenuous exercise, or other situations of high sympathetic drive. (Internation Journal of Obesity (1992) 16, 481) X The mechanisms by which diet cycling leads to negative health outcomes have not been intensively researched, but some have been implicated: X X + Diet induced hypercholesterolemia (American J Clin Nut X 1991;53;1404-10) X X + Diet induced depletion of Omega-3 reserves, believed to X protect against colon cancer, heart attack, etc.. X (Phinney, Am J Clin Nut 1992;56;781-2) X X + Decrease in HDL ("good") cholesterol X X + Loss of heart tissue X X + Loss of bone mass (USDA Grand Forks Human Nutrition X Research Center) X X + Increase in fat cell numbers (Bjorntorp and Sjostrom X METABOLISM V20;7;703) X X + Changes in fat cell receptors X X + Another ominous outcome is that the weight that is X regained is more likely to be in the upper body than X the lower, and for men at least, that type of weight X distribution has been linked to an increased risk of X heart disease. (University of California Berkeley X Wellness Letter, 5;4) X Some studies on human diet cycling are tabulated below. X X X X X X X X X X X X X X X X X X X Adiposity 101 42 3-9-93 X X X X Human Studies on Weight Cycling X ___________________________________________________________________________ |Study | Subjects Sample Results WC>BMI Health Outcome | |____________|_____________________________________________________________| |(Dale) | 20 f SKEWED FUDGED matched (short term) | |Optifast | 50 f selected FUDGED yes unknown | |Blackburn | 57 cyclers true yes n/a | |TRIM | 88 SKEWED FUDGED yes (short term) | |Jequier | f - - yes slow metab. | |Baltimore | 846 m volun. FUDGED ? glucose intol | |WECO | 2107 m all true yes? CHD | |Gothenburg | 2317 random true n/a CHD, diabetes | |Framingham | 5127 random true yes CHD | |Harvard | 11703 m alumni true n/a CHD, all | |Blair/MRFIT | 12866 m FEDERAL n/a n/a CHD | |____________|_____________________________________________________________| X X WC>BMI: Weight Cycling linked to increased fatness (BMI) A sample was judged SKEWED if subjects were selectively excluded from the cohort because they developed diabetes, CHD, morbid BMI, or other negative health outcomes linked to diet cycling after the commencement of diet cycling. Results were judged FUDGED if BMI was factored out, begging the question that diet cycling may damage health because of the increase in obesity from diet cycling. X A recent survey of European obesity experts showed they consider repeated dieting a greater causative factor for obesity than lack of will-power, physical inactivity, or depression leading to overeating. X By considering the studies by Drenick et al, Lissner et al, and Bjorntorp and Sjostrom, it appears that obese (BMI > 35) individuals with childhood onset obesity (BMI > 20 at age 5) who lose 12% or more of their weight are at the greatest risk of gaining back more than they lose, with the attendant bad health effects. The risk is a serious one, a slope of .5 to .9 BMI/year weight gain (higher in some) compared to 0.25 for normal adults. X As explained above, all the available studies that did not report adverse effects from diet cycling have been flawed because they removed the effect of weight gain caused by diet cycling. To correct this flaw, studies must match dieters and non dieters according to their physical characteristics and history *BEFORE* their first diet. X Weight loss studies should report the number and size of adipose cells before slimming, after slimming, and after weight regain. X X X X X X X X X X X Adiposity 101 43 3-9-93 X X X 7.6.1 Artificial Sweeteners There has been considerable media coverage of claims that artificial sweeteners hamper weight loss efforts. These appear to result from an American Cancer Society study that found a correlation between overweight and the use of artificial sweeteners. This correlation might better be explained by noting that people without weight problems generally avoid artificially sweetened products on account of cancer concerns, unfamiliar taste. Some complain that artifically sweetened beverages don't give them their "sugar high". Can you imagine a Diet Jolt Cola? Thin people may read labels on artificially sweetened products suggesting such products be used only by those desiring to reduce their caloric intake. X A University of Toronto study on the effects of Aspartame sweetened diet soda on randomly assigned subjects found no effect on food selection at a meal 60 minutes afterwards. Subjects who consumed a half liter of diet pop experienced reduced hunger for about 45 minutes. X A New England Deaconess Hospital (1F-16) study found that aspartame facilitated greater weight loss among obese women on a multidisciplinary balanced deficit diet that included exercise. X A Harvard Medical School study indicated Aspartame facilitated long term weight maintenance in a multidisciplinary weight loss program. X @ Concerns have been raised that ingestion of non-caloric beverages might trigger a hormonal response driven by a Pavlov response to the sweet taste. However, 12 subjects drinking 300 ml of diet Kool-Aid exhibited a very small insulin response consistient with the residual carbohydrate content of the drink. (An J of Clin Nutr 1990;52:335-41) X @Large numbers of dieters have reported difficulties in sustaining urinary ketones after consumption of dietetic beverages, such as diet cola, or slices of lemon in water. These difficulties disappear when when beverage intake becomes restricted to black coffee, black tea, or water. Although present only in small amounts, citric acid might be the offending substance because of the known ability of citrate to control carbohydrate metabolism at the subcellular level. Single-blind trials of citric acid added to drinking water indicated many were particularly sensitive to the citrate. (Am J of Clin Nutr 1992;56:217S-23S) 40-50% of people on ketogenic diets are sensitive to citric acid; they cannot tolerate the diet under these conditions. If difficulties arise, the only solution is to avoid fruits and beverages which contain citric acid, including most popular X X X X X X X X X X X Adiposity 101 44 3-9-93 X X X diet beverages. There is no test for this sensitivity. (Private conversation, 1992) X X 7.7 High Fiber Diet X High fiber diets have been proposed for weight loss from time to time. According to Consumers Reports, increasing fiber in one's diet does not induce long term weight loss. X Guar Gum, an agent for adding fiber to the diet, has been banned by the FDA. X Not all fibers are equal. Most fiber types, including the fiber in oatmeal do not have the metabolic effects of guar gum fiber. X 7.8 Low Fat Diets X Concerns about cholesterol levels have prompted nutritional authorities to favor high carbohydrate low fat diets. However, this fear of fat may be oversimplistic. X @"studies suggest that it is the nature of the fatty acids rather than the amount of fat in the diet which is important" (Proceedings of the Nutrition Society 1992: 51, 397-408) @Beef fat, not beef itself, is associated with elevations in cholesterol concentrations. Lean beef can be included in cholesterol-lowering diets provided it is free of all visible fat and the saturated fat content of the diet is low. (Journal of the American College of Nutrition 1993 12: 1: 86-9) X The negligible long term success rate of semistarvation diets has sparked interest in the weight loss possibilities of low fat diets. X This interest springs from a number of observations. X X + High fat (>>40% fat) diets cause weight gain in X research rats. Low fat evangelists fail to note that X high carbohydrate diets have proven even more fattening X to research rats. In addition, not all rats gain X weight on the high fat diet, and most rats revert to X normal weight when their diet is normalized. All of X the high fat rat diets seen in the literature involve a X profound increase in total energy intake, contrary to X most obese humans who have depressed energy intake. X X Replacing mother's milk (8% of calories from X carbohydrates) with a milk-substitute formula (56% of X X X X X X X X X X X Adiposity 101 45 3-9-93 X X X X calories from carbohydrates) grew fatter rats. (See X "The Role of Baby's Diet", below.) X X + Obese subjects often exhibit a greater carving for fat X than lean individuals. Fat craving is a common after X effect of energy deprivation. Following food X restriction, corpulent female rats had galanin (a X substance that increases fat appetite) levels 40-50% X higher than lean females or freely-fed corpulent X females. (Diabetes Research 1990 15,1-7) X X Since most fat people have been on numerous diets, fat X craving may be the result of dietary restriction, not X the initial fat inducing condition. Studies show fat X children obtain a slightly greater proportion of their X energy input from fat than thin children do. This X slight increase is decisively overshadowed by their X lower total energy intake. Pre-obese children consume X less energy (50 calories/day average) than their lean X counterparts. X X + Some studies suggest energy from fat additions to an X otherwise neutral energy balance cause a weight X increase short term, which may be more pronounced in X the obese. This effect has not been demonstrated X outside the context of induced overfeeding. In X "Oxidative and nonoxidative macronutrient disposal in X lean and obese men after mixed meals" (Am J of Clin X Nut, 1992;55;630-6), Owen et al report "Significantly, X there was no tendency for the obese men to have the X defect in suppression of fat oxidation after mixed X meals that had been reported by others". X Low fat diets come in two types, semistarvation and ad libitum. Most VLCD diets are low fat; the Cambridge Food For Life Ultimate Weight Loss Formula provides 6% energy from fat (3% by weight). It has been argued that the infamous Dr. Atkins Diet is sometimes a low fat diet because some people do not like fatty foods that are not also high in carbohydrates. X There is no epidemologic evidence indicating that total fat intake per se, independent of total caloric intake, is associated with increased adiposity in the population. Obesity itself has not been found to be associated with dietary fat in either inter- or intra- population studies. ("Diet and Health: Implications for reducing chronic disease risk"; Committee on Diet and Health Food and Nutrition Board Commission on Life Sciences, National Research Council; National Academy Council, Washington D.C. 1989.) X X X X X X X X X X X Adiposity 101 46 3-9-93 X X X "using a whole body calorimiter, we found no evidence of a decrease in 24-h energy expenditure on a high-fat diet compared with a high-carbohydrate diet." (American J of Physiology Feb 1990) X A Rockefeller University study found no significant variation in energy need as a function of percentage of fat intake (0 to 70%), Confirming the results of a landmark 1930 study, a Rockefeller University study found no significant variation in energy need as a function of percentage of fat intake (0 to 70%). (American Journal of Clinical Nutrition 1992;55;350-5) The 1930 study found that the long-term effect on body weight of any diet is related only to the total energy content of the diet. Other features of the diet such as carbohydrate or fat content did not, in the long run, have consequential effects on body weight. X "There is some problem in reconciling the short-term studies showing an association between high-fat diets and obesity with longer-term trials where there is no really strong evidence that high-fat diets do cause massive weight gain. There is the National Diet Heart Study in the United States, which lasted one year, and had men on diets varying in fat content from 40% to 20% of energy. The differences in body weight gain between these men were really very small" "Whatever happens to fat in terms of its being deposited preferentially on short-term overfeeding, there seems to be no difference between carbohydrate and fat supplements in terms of energy balance when you look over a period of 50 to 80 days." "If [dietary] fat is a promoter of weight gain and obesity, it is more likely to be through its effects on the hedonic characteristics of the food source [which would raise total caloric input] than because of any mysterious effect on intermediary metabolism" (Discussion, Nutrition Reviews, Vol. 50, No. 4) X "Comparisons of obese adolescents to normal peers have demonstrated comparable energy intake and nutrient distribution." (Journal of School Health 2/92) X @The anorectic effects of serotonin reuptake inhibitors and 5-hydroxtrytophan, potent weight control drugs, are evidenced by decreased carbohydrate intake, not decreased fat or protein intake. X @ In a review of six randomised, controlled, primary prevention trials, Muldoon et al found that lowering of raised serum cholesterol in middle-aged subjects by diet, drugs, or both was associated with a significant decrease in the number of deaths from CHD but not in total deaths. There was a significant increase in mortality due to X X X X X X X X X X X Adiposity 101 47 3-9-93 X X X suicides or violence: compared with control groups, the treated groups had 28 fewer deaths from CHD and 29 more deaths from suicide, homicide, and accident. Monkeys on a low fat diet were significantly more aggressive than were controls on a normal diet. (Lancet 339: March 21 1992, p 727) X There is some concern that low-fat diets induce depletion of the body's Omega-3 reserves, believed to protect against colon cancer, heart attack, etc., and to promote lipolysis ("fat burning"). X 7.8.1 The Cornell Low Fat Study A Cornell University study "Weight loss on a low fat diet" has been widely quoted by low fat diet evangelists. This study is interesting primarily for what the mass media never reported about its methods and results. X The Cornell study located 25 non-smoking women of greater than ideal weight who were not cognitively restricting their food intake to achieve weight control. "Unrestrained eaters were desired as subjects". Since the majority of overweight women actively try to reduce their weight, this study's sample is not representative of overweight women. Of the 25 subjects that passed the initial screening, 9 were excluded from the study for unstated reasons, and another 3 dropped out during the low fat phase of the study, leaving only 13 subjects. Why all the fuss about sample selection? The researchers undoubtedly wanted to use subjects who were not truly obese (they don't respond to food the same as normalweights do). Neither did the researches wish to risk using women whose metabolisms had been depressed by previous diets. X Subjects were randomly assigned to ad libitum diets with low fat (20% calories from fat) or high fat (40% calories from fat) foods. Subjects were placed on one diet or the other for 11 weeks. After an 7 week "washout period" the subjects switched diets. Subjects who first lost weight on the ad libitum 35-40% fat control diet subsequently failed to lose weight on the low fat diet. X Caloric intake on the low fat diet was markedly depressed at the beginning, with an initial weight loss of almost a pound a week. Within 11 weeks, caloric intake on the low fat diet was increasing. The difference in calorie intake was cut in half, and weight loss nearly halted. X "We are unable to explain the minimal effect that the low fat diet had in the second half of the study". The study paper also indicated that weight loss on the low fat diet X X X X X X X X X X X Adiposity 101 48 3-9-93 X X X was much less than expected from the caloric difference between the two diets, indicating a "metabolic disadvantage" compared to other diets. X In addition, the media failed to report that the subjects regained twice as much weight in the 7 week period after the low fat diet as did the subjects on the control diet. The Cornell researchers have not seen fit to report a long term followup. X In a study of 171 women on a two year low fat diet, maximum weight loss of 3.2 kg was reported at 6 months. By year 2 some of the weight was regained. The standard deviation was more than twice the average weight loss. In other words, quite a few actually gained weight on the low fat diet, not counting the 13 that dropped out of the program. (Am J Clin Nutr 1991;54:821-8.) X The Pritikin Institute promotes an ultra low fat diet to improve cardiovascular health. In a 1991 radio interview, a Pritikin Institute official characterized the weight loss effects of the Pritikin ultra low fat diet as "slight". Ann Louise Gittleman, Pritikin Longevity Center nutrition director, reported in 1992 that weight loss on the Pritikin diet was temporary for most. X A Rockefeller University study reported energy intake required to maintain body weight is not affected by wide variation in diet composition. Even with extreme changes in the percentage of energy from fat (0% - 70%) there was no detectable evidence of significant variation in energy need as a function of percentage fat intake. (American Journal of Clinical Nutrition 1992;55;350-5) "Sixty years ago, LH Newburgh and his colleagues examined the possibility that so-called endogenous obesity might be the result of special metabolic factors unrelated to energy intake or physical activity. They found no evidence for such purely endogenous obesity and also demonstrated that the long-term effect of any diet on body weight is related only to the total energy content of the diet. Other features of the diet such as carbohydrate or fat content did not, in the long run, have consequential effects on body weight." X The incidence of obesity does not necessarily follow the amount of dietary fat. The average U.S. daily fat consumption is 2.52 ounces, with 10% of males obese; the average Australian daily fat consumption is much less at 1.54, but 14% are obese. (LONGEVITY, May 1992) X "There is evidence that altering the proportion of the calories in the diet from fat, carbohydrate, and protein can X X X X X X X X X X X Adiposity 101 49 3-9-93 X X X have a limited effect on weight loss; however the effects appear to be quite small" (Methods for Voluntary Weight loss and Control, NIH Technology Assessment Conference Panel, Annals of Internal Medicine June 1992, 116;11) X In the presence of dietary carbohydrate, the preferred fuel is glucose and the capacity to mobilize fat is limited. Factors that increase blood glucose during dieting may stimulate insulin release and all the metabolic sequelae of circulating insulin. Fatty acid synthesis is activated and lipolysis is profoundly inhibited by insulin even at very low concentrations of the hormone. (Am J of Clin Nutr 1992;56:217S-23S) X "If ever proof were needed that the proposition that there is a cause-and-effect relationship between diet and breast cancer far exceeds scientific data, the US National Institutes of Health's plan to conduct a $10 million clinical trial is proof indeed. Despite abundant evidence that dietary fat bears no relation to development of cancer of the breast, the NIH intends (under the fashionable umbrella of "women's health") to initiate a study of 40,000 women (half of whom will be randomly assigned to consume no more than 20 per cent of their calories in fat) to try once again to prove a link that is probably not there. ... Why then does NIH insist on spending $10 million on a study whose hypothesis seems to be little more than wishful thinking? Is it only because of the faddish infatuation with fat as the root of all dietary evil? In the United States, as elsewhere, money for scientific research is in short supply. There are many ways the NIH could better spend its $10 million." (Editorial in NATURE - VOL 359 - 29 OCTOBER 1992) X 7.9 Dieting Gourmets X A diet designed by Michel Montignac restricts the eating of certain kinds of foods together. Fat and proteins marry well, but not with carbohydrates. Even a single French fry is forbidden, as is sugar. X Montignac satisfies his sweet tooth with artificially sweetened desserts or low-sugar chocolate mousse. X The diet's basis is the relationship between insulin and the creation of stored fat. For example, the carbohydrate in several slices of whole-wheat bread at breakfast will not cause weight gain, but adding butter will. X The method recommends plenty of fresh and cooked vegetables, meat, poultry and fish, and up to three glasses of red wine X X X X X X X X X X Adiposity 101 50 3-9-93 X X X per meal. X Montignac encourages dieters to eat carbohydrates as main courses. Fruit, which must be delayed until three hours after a meal, becomes a morning or midnight snack, not a dessert. X "The man who put France on a diet" has drawn fire from the nutrition establishment. Gerard Pascal, head of nutrition and food hygiene at the National Institute of Food Research, says Montignac's method is dangerous and scientifically unfounded. Pascal urged the overweight to eat a bit of everything. "That's difficult and unspectacular, but in the long run, it's the only valid rule to follow." X Montignac is not sure his method will thrive in the United States, where fast food and sugar-laced packaged foods are dietary staples. (APn 01/23/1993) Scientific papers on this diet technique, is any, have yet to come into prominence. X 7.10 Low Carbohydrate Diets X Low carbohydrate weight loss diets have been used for centuries. Sugar consumption is lower, low carbohydrate diets are more popular, and the incidence of hyperobese individuals is lower in Europe than in the U.S.3 X X X X X X X X X X X X X X X X X X X X __________ X X 3. International Journal of Obesity 1992, 16,565-572 X X X X X X X X X X X X Adiposity 101 51 3-9-93 X X X A number of short term studies, mostly in the 50's and 60's, showed a marked advantage in weight loss from high protein, low carbohydrate diets compared to diets higher in carbohydrate. X Weight Loss on 1800 kcal Diets with varying CHO (grams/day) X _______________________________________________________ |Carbohydrate | Fat Loss (kg) % LBM Loss Tiredness | |_____________|________________________________________| | 104 | 8.38 24.7 1 | | 60 | 10.2 15.9 2 | | 30 | 14.85 4.9 3 | |_____________|________________________________________| X Each group had 3 subjects. All three diets had 115 grams of protein per day. Tiredness indicates the number of subjects reporting this symptom. (Am J of Clin Nut 1971 290-6) X Another study compared two 590 kcal diets. The "ketogenic" diet had 52g protein, 10g CHO, and 38g fat. The other diet had 50g protein, 10g fat, and 76g CHO. The ketogenic diet did not exhibit any advantages. At 590 kcal/day neither of these diets was representative of popular "low carbohydrate" regimens. (METABOLISM, 1992 41:4: 406-14) X @ In the presence of carbohydrate, the preferred fuel is glucose and the capacity to mobilize fat is limited. Factors that increase blood glucose during dieting may stimulate insulin release and all the metabolic sequelae of circulating insulin. Fatty acid synthesis is activated and lipolysis is profoundly inhibited by insulin even at very low concentrations of the hormone. (Am J or Clin Nut 1992;56;217S-23S) X These studies indicate a low carbohydrate diet with generous protein allowance provides superior fat loss, reduced lean tissue loss compared to other types of weight loss diets. The main disadvantage is a greater incidence of tiredness, not unexpected considering the dramatically greater fat loss. X Of particular interest is the famous "Atkins Diet Revolution" developed by Dr. Robert Atkins, a New York cardiologist. X Dr. Atkins claims that 95% of overweight is metabolic and not an eating disorder. His solution is to limit sugar and other carbohydrates to the dietary levels man experienced before the agricultural revolution. X X X X X X X X X X X X Adiposity 101 52 3-9-93 X X X Dr. Atkins claims that high carbohydrate diets promote Candida Albicans overgrowth ("yeast infections"), which can interfere with weight management. His lab tests confirmed this condition in a third of his patients. X At the start, the Atkins diet severely restricts carbohydrates. As weight loss proceeds, carbohydrates are increased to modulate the rate of weight loss. Except for carbohydrates, Atkins dieters eat ad libitum. X The media attention afforded Dr. Atkins' Diet Revolution and Dr. Atkins' claim that high carbohydrate consumption promoted obesity and insulin resistance triggered a heated response from the American Medical Association Council on Foods and Nutrition. The Council, whose members and their links to high carbohydrate food producers were not disclosed, blasted the Dr. Atkins diet in the June 4 1973 Journal of the American Medical Association. While Dr. Atkins rebuts many of the Council's points in his 1992 sequel "Dr. Atkins' NEW Diet Revolution," the Council's observation that "It is unfortunate that no reliable mechanism exists to help the public evaluate and put into proper perspective the great volume of nutritional information and misinformation" is, sadly, as true in 1993 as it was in 1973. X Since the AMA Council on Foods and Nutrition put the Atkins diet off limits, few investigations of the Atkins diet have appeared in the literature. Consumer Reports' Rating the Diets has rated Atkins as "absolutely not recommended"; ironically their top rated diet (Nutri/Systems) was the first to make payments on product liability lawsuits. X Critics blast the Atkins diet as a high-fat regimen that increases serum lipids. Dr. Atkins, a cardiologist, responds: ``Am I advocating a high-fat diet? Not in the long run. As my critics twenty years ago were forced to acknowledge when they looked into the matter, and as Professor John Yudkin proved, this isn't a high-fat diet. ============================================================================== ú Subject: Adiposity 101 3/4 The average person on a low-carbohydrate diet eats less fat than he was eating on his previous "balanced" diet - the average diet in America today.'' X X ``the AMA [Council on Foods and Nutrition] said they were X "deeply concerned about any diet that advocates the X unlimited intake of saturated fats and cholesterol-rich X foods." Then they scrutinized all the medical literature X they could bring to bear and came up with a single case X described in 1929.4 "This was the study of the Arctic X X X X X X X X X X X X X Adiposity 101 53 3-9-93 X X X X explorer, Vilhjalmur Stefansson, who, impressed with the X health of the native Eskimos he observed, volunteered X with an associate to be observed for a year on an all X animal food diet. In this study, one of the two subjects X cholesterol levels did go up but the other's dropped. X The AMA inaccurately reported that both men had X cholesterol increases." X X Let's look at their language: "Individuals responding to X such a diet with a rise in blood fat will have an X increased risk of coronary heart disease." Absolutely, X All I can say is: "I agree, and individuals who jump off X a curb with a parachute and are thereupon attacked by an X enraged bull will have an increased risk of torn X garments." The AMA's ad hoc nutrition panel had to phrase X it that way, because they knew, of course, that they X could not find any evidence that would have allowed him X to make a stronger statement. X X I think it is clear from their circumspect language that X the AMA was aware of the difference between the results X when fat and cholesterol are added to a high-carbohydrate X diet and the results that occur when they are added to a X low-carbohydrate lipolytic diet. In the usual scenario, X when carbohydrates are a large part of the diet, the X undesirable lipid reading may get worse if there is an X increased intake of fat as well; on the Atkins diet, such X a result is rare indeed.'' (Chapter 15, Dr. Atkins NEW X DIET REVOLUTION, 1992) X @ It should be noted that serum cholesterol increases are encountered with other types of diet. (American Journal of Clinical Nutrition 1991;53;1404-10) High-carbohydrate diets lead to several changes in carbohydrate and lipid metabolism in patients with NIDDM that could lead to an increased risk of coronary artery disease. These effects persist for more than six weeks. It seems reasonable that the routine recommendation of low-fat high carbohydrate diets be reconsidered. (Diabetes Care 12:94-101, 1989) X Tiredness is a common, but hardly universal, complaint on low carbohydrate diets. Some of these problems may be related to citric acid interacting with the Atkins diet (see "Artificial Sweeteners", above). Several Usenet readers have reported abandoning the Atkins diet as a result of side X X ____________________________________________________________ X X 4. See Dr. Atkins' footnote on this study. X X X X X X X X X X X X Adiposity 101 54 3-9-93 X X X effects and the bad publicity. X Other problems include palatability, inconvenience and expense of obtaining low-carbohydrate and sugar-free foods. X Dr. Atkins' 1992 book claims "the 10,000 active patients at the Atkins Center for Complimentary Medicine in New York are living testimonials to the major health improvements derived from a low-carbohydrate diet." Dr. Atkins advertises books and vitamins on his nationally syndicated radio talk show (1-800-2-ATKINS, 1-800-6-ATKINS). X This author has not been able to find a single study of the Atkins ad libitum low carbohydrate type of diet in the scientific literature. The available low carbohydrate studies have used energy restricted diets profoundly different from Atkins' regime. X A relatively recent paper appeared in the Feb 1973 American Journal of Clinical Nutrition, "Response of body weight to a low carbohydrate, high fat diet in normal and obese subjects". This paper is unusual for diet studies in that it discloses the individual results of each of its obese subjects instead of hiding them in the arithmetic mean. "we treated obese subjects with high fat, low carbohydrate diets. If the carbohydrate content of the diet was not more than 50 to 60 g/day and the fat content approximately 150 g/day, an average daily weight reduction of 0.3 kg was achieved. The cholesterol and triglyceride concentrations in the serum, which had been raised at the beginning of the experiment, invariably showed a tendency towards normalization under this dietary program." X A Scottish study found lowering carbohydrate intake doubled weight loss, increased fat oxidation, and reduced metabolic slowdown compared to lowering fat intake. X These papers appear to confirm Atkins' claim that his diet has a "metabolic advantage". The idea behind "metabolic advantage" is that a suitable low carbohydrate diet provides weight loss at a much higher caloric intake than other types of diets, with much less lean tissue loss. By comparison, the Cornell low fat diet study discussed above found weight loss was much less than expected from the reduction in caloric intake. X In the presence of dietary carbohydrate, the preferred fuel is glucose and the capacity to mobilize fat is limited. Factors that increase blood glucose during dieting may stimulate insulin release and all the metabolic sequelae of circulating insulin. Fatty acid synthesis is activated and X X X X X X X X X X X Adiposity 101 55 3-9-93 X X X lipolysis is profoundly inhibited by insulin even at very low concentrations of the hormone. (Am J of Clin Nutr 1992;56:217S-23S) Several recent papers have reported low carbohydrate diets to be better than the generally accepted low fat diet for diabetic control. X One of the Council's criticisms of the Atkins diet was loss of appetite. Such a criticism calls into question the judgement, if not the honesty, of the Council's members. Atkins considers appetite reduction a virtue of his diet, as would most dieters. However, if this loss of appetite is sufficient to decrease energy input below maintenance levels, then studies of energy restricted low carbohydrate diets may be relevant. These studies did not find a long term "metabolic advantage" to carbohydrate restriction. It remains to be seen if the anorectic effect of the Atkins diet is powerful enough to reduce energy input to the low levels used in these studies. X @ Atkins estimates that less than a third of individuals in his diet are "fat-sensitive" and will develop a less favorable cholesterol level on a high-fat [low-carbohydrate] diet than on a low-fat diet. His 1992 book includes procedures for testing for sensitivity to various types of fat and appropriate diet modifications. X Dr. Atkins reports long term results that are much better than those obtained with other diets. He has offered to make his patient records available to researchers, something Weight Watchers, Nutri/Systems, et al refuse to do. His favorable results, however, may be the result the same selective dropout mechanisms that generate spurious positive results in other diet studies. X 7.11 Diets - the BOTTOM LINE X "weight will return toward its baseline level whenever a previously instituted perturbation (such as diet, exercise, modified protein fast, behavior modification, or jaw wiring) has been completed. In this case, continued diet, exercise, and behavior modification also did not help the subjects to avoid regaining lost weight." X "Both the medical profession and society look with disfavor on obese people and obesity in general. For example, students at a well-known university preferred a number of less savory people to obese individuals as potential marriage partners. Obese people are treated negatively in cartoons and in literature. Many believe that obese people need only to "close their mouths" and to be more motivated to lose weight. Thus use of medications to correct a X X X X X X X X X X X Adiposity 101 56 3-9-93 X X X characterologic defect is, in the opinion of physicians and the public, deemed inappropriate." X "Unfortunately, a lack of understanding of both the natural history of obesity and its diversity adds to the pejorative view of obese people and of anorexiants. Some health professionals are not aware of data concerning mechanisms present in the human organism that act to countervene perturbations in body weight and that may account for the apparent failure of interventions, including medications." (Clin Pharmacol Ther, May 1992) X X An article by William Bennett in the Annals, New York Academy of Sciences, (book length issue on Human Obesity) gives the bottom line on diets. "Data on the dietary treatment of obesity have been accumulating since 1931. Nothing in the chronicle suggests that worthwhile progress has been made by pursuing efforts to teach people more effective ways to restrict their food intake. There now is enough information to permit the prediction that results will be mediocre in the short run and after several years the results will be less than acceptable. The burden should now be on the investigator to establish a strong reason for undertaking yet another study of intake restriction, including studies employing behavior modification aimed primarily at altering eating behaviors. X Committees reviewing the use of human subjects in these experiments should not assume that they are ethically uncomplicated. The low probability that information of therapeutic value will result from such a study should weigh heavily in any deliberation on whether to authorize it." X "I can see little reason for intake restriction to receive continued support, either as a subject of research or as an accepted therapy for obesity. Bloodletting as a therapy for pneumonia was abandoned about a century before penicillin was discovered. It required a modicum of courage and good sense on the part of practitioners who turned away from the practice, but there is no reason to believe their patients suffered from this lack of therapy." X "A survey of studies published 1977-1986 and reporting on dietary or behavioral treatment of obesity reveals that the maximum percentage of body weight lost is, on average, 8.5 percent - no different from the value, 8.9% in similar studies from 1966-1976, as reviewed by Wing and Jeffery." X "The goals and research methods of studies on dietary treatments for obesity are overdue for ethical as well as X X X X X X X X X X X Adiposity 101 57 3-9-93 X X X scientific reevaluation. The same may be said for the numerous programs providing such treatment outside the context of research." X A final footnote on combining diets and exercise. A Harvard Health letter compared results of 1982 and 1991 surveys of doctors' lifestyles. Since 1982 the doctors reduced their consumption of red meat, fat, and cholesterol. They increased their dietary fiber and exercised more. Unfortunately, the increased attention to diet and exercise did not produce leaner bodies; the proportion reporting weight problems increased from 29 to 39 per cent. X While diet evangelists continually assert that new wrinkles in 60+ year old treatments are improving weight loss outcomes, the long term success rate of even the best available weight loss programs using diet, exercise, and behavior modification remains less than five per cent. (NIH conference on voluntary weight loss, Mar 30-Apr 1 1992) X X 8. FLAWED RESEARCH X The quality of diet research and media coverage on the problem of adiposity often leaves much to be desired. The vast majority of this research is so poor it would never be accepted by the FDA as proof of an ethical drug's efficacy and safety. X The reader should beware of two common flaws in popular obesity studies: X 8.1 Correlation .vs. Cause and Effect X A typical correlation study might show that joggers are thinner than couch potatoes. This is a *correlation*. Such data are generally cited as proof that obesity is caused by lack of exercise, with the implication that fat couch potatoes will become thin if only they get off their lazy butts and exercise. X What is the error in drawing such a conclusion? The error is the unstated assumption that the correlation proves a particular cause and effect. In fact, other cause and effect relationships may be involved. Conventional wisdom concludes: Lack of exercise causes obesity. The other explanation for the observed correlation is: Obesity and associated impaired muscle development makes sports activities unpleasant and frustrating if not impossible. X "While the link between exercise and health in some large X X X X X X X X X X X Adiposity 101 58 3-9-93 X X X epidemologic studies seems powerful, intervention and outcome studies suggest a more qualified correlation. ... Yet "we still have no clinical trial to demonstrate that increasing activity in a group of sedentary people reduces the rate of disease vs sedentary controls," says William Haskell, PhD, also a member of the Stanford faculty." (JAMA June 12, 1991) X Correlation studies that draw conclusions or make recommendations without properly evaluating alternative models of causality are fundamentally flawed and must be treated with suspicion. X 8.2 Flawed Sample Selection/Distribution X Non-random selection or partitioning of the sample population flaws many studies that otherwise appear to be well designed. X One cannot allow subjects to select which experimental group they will join because the selection process may be stronger than the experimental intervention. News media might not understand the implications, but the study will be flawed. X For example, a study on the mortality effects of obesity was based on patients who had repeatedly lost and regained weight, compared to lean individuals. Was the higher mortality caused by obesity, by the dieting, did diet cycling cause both, or did genetic factors cause all three? X Studies comparing the relative success of alternative treatments rarely assign subjects to the alternatives at random. The factors that determined sample selection and partitioning may be more important than the alleged independent variable. X Diet studies typically exclude dropouts from their data. This is not acceptable in weight loss research because dropouts have lower weight loss and greater weight regain. Excluding even a few such data points distorts the experiment because the variability between subjects is much greater than the average weight loss. X @ EXAMPLE: Let us put 15 subjects through a thought experiment. 5 lose 20 pounds on the New Fat or Fit program, 5 gain 20, and 5 end up the same. The average weight loss is (5x20-5x20 +0 = 0) 0, about as well as real diet programs. But before the 5-year weigh-in, two of the subjects who regained their weight and three of the unfortunates that out on an extra twenty gave up on Fat or Fit and went on an Atkins' diet. The five that dropped 20 X X X X X X X X X X X Adiposity 101 59 3-9-93 X X X are of course eager to report the success of their superior will power to the researchers. So now we have (5x20 -2x20 +3x0 = 60/10 subjects = 6) 6 pounds average loss. That 6 pounds is completely bogus, but that's how diet papers work. X X X 9. TRUTH IN RESEARCH PAPERS X The honesty and integrity in life sciences research has increasingly come under question. X We understand the pressure on a corporation or trade institute to manage information about the safety and efficacy of its products and services. Such pressures are not limited to the corporate sector. Weight loss researchers live by the "publish or perish" syndrome. Exaggeration of weak results is sometimes a necessary expedient to secure continuing research funding. "When all you have is a hammer, everything starts to look like a nail" applies to research projects. X "It is seldom necessary to list individual results in a paper. Data can usually be summarized by a measure of location and a measure of dispersion. A common practice is to list the arithmetic mean, standard deviation (S.D.) and the number of observations (n) used to estimate these statistics. If only a few observations are available the dispersion is better indicated by the range. If the distribution is significantly skewed [not a "normal distribution"] both the median [50th percentile] and range [minimum and maximum] should be cited." (Journal of Endocrinology, 1992) X How can one spot "fudged" research? One way is to look at the way data is presented. If mean (average) values for the experimental groups are presented, check the standard deviation values. The standard deviation must be small compared to the reported differences between groups. If the standard deviation is comparable to the differences between groups, the data can not be used to analyize individuals. X Diet evangelists dismiss or downplay the importance of genetics and other inborn differences affecting the development of obesity. Large standard deviations highlight the biological differences between fat and thin people. If the standard deviation is not disclosed, the researcher is hiding something from the reader. @"the mean net weight gain in 1423 women as a consequence of pregnancy was found ... to be small (0.5 kg). Nevertheless, this seemingly modest increase concealed the fact that 15% of these women X X X X X X X X X X X Adiposity 101 60 3-9-93 X X X had actually gained more than 5 kg" (IJO 16, 935) X Diet studies typically exclude dropouts from their data. This is not valid in weight loss research because subjects tend to drop out after frustration with poor weight loss. Dropouts have lower weight loss and greater weight regain. Excluding even a few such data points generates a false positive finding because the variability between subjects is much greater than the average weight loss (SD >> M). Goal directed programs and programs that dogmatically insist subjects will succeed if only they follow the regimen provoke highly skewed dropouts. X Weight loss studies often present the average weight loss of a subset of the experimental cohort. Most such samples are not representative of the overweight population, yet vital questions of relevance to the overweight population are rarely addressed. What portion of the overweight population was not eligible for or excluded from the program, thus introducing selection bias? (Williamson & Levy, Int J of Obesity, 1988, 12, 579-83) X @Long term studies pose further problems for studies without a non-dieting control group. Williamson and Levy analyzed weights recorded for medical purposes at two clinic visits separated by intervals of 1 to 5 years. These were 332 adult patients who were initially at least 20 per cent overweight. The 59 patients measured over a 5 year interval showed an "apparent weight loss" for 31 per cent of this group with a mean decrease of 7.3 kg. This long term random weight loss is comparable to the positive results reported by some diet and behavior programs. "Some variation in an individual's body weight is expected to occur over time for a variety of reasons including mood swings, health status, seasonal variations in food intake, amount of exercise, tobacco smoking, pregnancy, and dieting attempts. These intervening variables have not been well controlled in long-term weight loss follow-up studies. X The sub-group of subjects who maintain a weight loss is usually reported in isolation without comparison to the majority of overweight subjects who originally entered the survey or program. These results suggest the degree of variation that a [non-dieting] control group would contribute both to the proportion of overweight subjects who would have naturally decreased in weight at a specific re- measurement interval and the mean amount of weight by which they would have decreased. The sample size in this study exceeds that of most long-term follow-up studies reported in the literature." X X X X X X X X X X X X Adiposity 101 61 3-9-93 X X X @Few studies are available of body composition changes after weight losses from standard dieting programs. Weight losses beyond the initial glycogen and water shifts have proven difficult to achieve. (Weight loss of 5kg (11 pounds) or less may not involve any loss of fat!) When they do occur it is difficult to verify the actual protocol the subjects followed. Subjects often report they often became `stuck' on traditional protocols and resorted to some more drastic form of food restriction to achieve weight loss. They are often reluctant to report such behavior at the time of the actual diet. (Am J of Clin Nutr 1992;56:217S-23S) X Unless a significant loss beyond baseline is demonstrated by weight loss studies and programs, no effect should be attributed to the program. Control groups that account for random weight changes (mostly from unsupervised dieting) are essential in studying the long-term maintenance of weight loss. X Any study that takes weight loss as a goal should include the following information: X X + Weight, height, and Body Mass Index (BMI) for subjects X at entry, then weight and BMI at each follow-up time. X X + Number and size of fat cells before slimming, after X slimming, and after weight regain. X X + When expressed as means, these values should be X accompanied by the standard deviation, not the standard X error. X X + Data for males and females should always be separated. X X + If the study contains more than one experimental group X and/or a control group, subjects must be randomly X assigned to each group. X X + If the study contains more than one experimental group X and/or a control group, the data should be presented X for each group. X X + Studies with 50 or fewer subjects should present X individual data. X X + Data should include followup for a minimum of three X years after treatment ends. X X + If there are drop-outs, the remaining number of X subjects should be recalculated and reported along with X the mean weight at follow-up. Almost all drop-outs X X X X X X X X X X X Adiposity 101 62 3-9-93 X X X X regain their weight loss or more, and must be X calculated this way. X X + Weight loss studies should report the number and size X of adipose cells before slimming, after slimming, and X after weight regain. (Based on recommendations by by William Bennett, Harvard Medical School Health Letter) X X 10. MEDIA DISTORTION X Heavy advertising, a "thin is in" ethic, media preoccupation with unusually obese individuals, and built-in repeat business have bloated the diet industry into a 33 billion dollar a year enterprise. X The media often sensationalize studies confirming public stereotypes while ignoring research that disproves those stereotypes. The following news release is typical: X "Why Johnnie gets fat X CHICAGO, Reuter - Television may be contributing to a near epidemic of obesity among American children because it drives metabolism dramatically lower, even below levels found in youngsters who are simply resting, researchers said on Monday. X The metabolic lowering -- caused by a still unknown mechanism -- may combine with the high-fat snacks that often accompany the hours so-called couch potatoes spend in front of the tube, according to a study published in the February issue of the medical journal Pediatrics. X It said obesity affects as many as one out of every four U.S. youngsters, as well as about 30 per cent of adults." While entranced by the sedating effect of a "The Wonder Years" episode on 31 children measured for a Master's thesis, the media completely ignored the lead article in the same issue. A 1250 child study by Stanford and NICH that concluded that "television viewing time appears to have only weak, if any, meaningful associations with adiposity". (Pediatrics 1993; 91:273-80) X As Professor Garner's 1990 testimony before the House of Representatives indicated, deceptive advertising is "standard operating procedure" in the weight loss industry. While a isolated deceptive diet/exercise ad may not be too misleading to the public at large, the collective effect of such deception (Nazi Big Lie effect) creates great damage. X Weight Watchers, Nutri/Systems and other diet promoters refuse to divulge their long term weight loss data. X Misleading advertising is, unfortunately, normal for the diet industry. The majority of diet food products tested X X X X X X X X X X X Adiposity 101 63 3-9-93 X X X for the New York state Consumer Protection Board contained more calories than listed on their package labels. 80 percent of the diet food products tested exceeded claimed calories, some by as much as 73 calories per serving. Added sugar has been found in 25% of orange juice brands described as pure and unsweetened. X Advertising ethics are no better in the related exercise industry. A NordicTrack ad claimed a fat person could lose up to 1100 calories per hour, several times what an endomorph with middle age spread could reasonably expect. X X 11. NEW TECHNOLOGY X 11.1 STIMULATION OF THERMOGENESIS X Thermogenesis refers to the generation of body heat in muscle and brown adipose tissue (BAT).5 Lean subjects increase thermogenesis in response to meals, exercise, and cold weather. Obese subjects show less of each of these responses than lean subjects. Obese subjects are less tolerant to long term cold exposure because of their inferior thermogenesis capability. X These facts have prompted many investigations into the possibility of reducing obesity by increasing thermogenesis in the obese. X In their book "Life Extension Weight Loss", Pearson and Shaw suggest thermogenesis enhancing drugs and cold exposure as ways to burn up fat. X Caffeine, ephedrine, nicotine and other materials have been shown to increase metabolism in humans. Aspirin increases the thermogenic effectiveness of ephedrine in obese but not lean women. Some are associated with weight loss during the treatment period. Common side effects of such treatment include high blood pressure and heart palpitations. X Ephedrine quadrupled the weight loss of obese women whose metabolisms had been depressed by previous dieting. (International Journal of Obesity, 1987: 163-8) X X X __________ X X 5. There is some controversy about the location of X thermogenesis in adults (BAT or muscle tissue). X X X X X X X X X X X X Adiposity 101 64 3-9-93 X X X A double-blind Danish study reported that ephedrine 20mg + caffeine 200mg administered three times daily dramatically increased fat loss and fat oxidation (see "fast fibres") and reduced loss of fat-free mass. Three of the 8 patients on E+C complained of insomnia, palpitations, and tremor, respectively. (Metabolism, 41;7 July 1992) X @ A combination of ephedrine(75-150mg), caffeine(150mg), and asprin(330mg), in divided premeal doses, supports modest, sustained weight loss even without prescribed caloric restriction, and may be more effective combined with diet. (IJO 1993 17 (Suppl 1) S73-8) X X Smokers gain weight when they quit smoking; their final weight averages the same as that of non smokers. This suggests nicotine reversibly depresses weight, 6 to 7 per cent according to University of Wisconsin researcher Richard Keesey. Nicotine reduces weight by increasing metabolism, not by reducing appetite or food intake. A growing number of young women have discovered this, and cigarette smoking is gaining popularity as a weight control measure. X Pearson and Shaw recommend nicotinic acid to increase thermogenesis and as a recreational drug. X A study of obese women on a swimming program suggests their heat loss to water had the opposite effect, increasing their fat stores. It's been reported that women gain 10 pounds in less than a week's time when they move to Alaska; they lose this weight when they move back to a warmer climate. This weight gain may be the result of BAT lipogenesis. X It has been suggested that early exposure to cold might promote adult leaness. (p. 75, Obesity and Leanness - Basic Aspects) Improvements in household heating in this century may contribute to an increase in obesity. X 11.2 GROWTH HORMONE TREATMENT X (Also called somatropin, or ST.) X @ Maximally effective doses of ST can reduce lipid accretion rates and adipose tissue mass by as much as 80%, and increase protein (lean tissue) deposition by 50%. ST affects numerous target tissues to effect marked changes in nutrient partitioning. Many of the metabolic effects are a direct action of ST, involving a variety of tissues and the metabolism of all nutrient classes, i.e., CHO, lipid, protein and minerals. X X X X X X X X X X X X Adiposity 101 65 3-9-93 X X X These metabolic changes are important because they: (1) establish the rate of lipid accretion and, therefore, the extent to which ST affects body composition in a growing animal, (2) play a key role in redirecting nutrients (e.g., glucose), normally destined to be deposited as lipid, to other tissues thereby supporting the nutrient needs for lean tissue accretion during growth. When anmals are in positive energy balance, ST causes a reduction in lipogenic rate. The ability of ST to reduce lipid accretion in growing pigs is the result of a decrease in insulin sensitivity of fat cells, which reduces lipid synthesis. The effects of ST are chronic rather than acute. (Proceedings of the Nutrition Society (1992) 51, 419-31) X Human Growth Hormone promotes muscle growth and fat loss. Growth Hormone restricts glucose incorporation into fat cells. The pituitary gland releases Human Growth Hormone (HGH) in bursts, mostly during the early hours of sleep. The obese produce almost no HGH bursts. Reduction of plasm insulin levels does not restore GH to normal in obese children. X Obesity is associated with reduced 24 hour integrated concentrations of growth hormone (IC-GH) and elevated concentrations of insulin (IC-I) compared to lean individuals. The difference in growth hormone levels is greatest in childhood. The difference in growth hormone between lean and obese children are typical of poorly growing children with classical growth hormone (GH) deficiency. In contrast to children with classical GH deficiency, obese children are generally normal or above average for height, growth rate, osseous maturation and IGF-1 levels. X A study reported in the Dec 3 1990 Wall Street Journal reported that short children treated with growth hormone lost a "drastic 76 per cent of body fat" while gaining as much as 25% lean body mass (compared to untreated controls). X Obese individuals normally release very little or no detectable HGH bursts. Even under the most strenuous exercise, obese individuals release only a small fraction of the HGH lean sedentary individuals release in normal sleep. X A study of lipid metabolism in lean and pre-obese swine (pigs of normal weight which will become fat) indicated low levels of growth hormone at least until sexual maturity, and an enhanced deposition of blood lipids as fat compared to lean subjects. (International Journal of Obesity 1990, 14, 21-29) This enhanced deposition is significant in two ways. First there is the direct accumulation of fat. Secondly X X X X X X X X X X X Adiposity 101 66 3-9-93 X X X this deposition of fat "short circuits" metabolism of blood lipids into cholesterol and steroid hormones. This theory helps explain why destruction of fat tissue allows animals to grow up with more muscle mass than identical but untreated controls. X @Growth Hormone deficiency in adults is associated with psychosocial maladjustment, reduced muscle strength and reduced exercise capacity. Body composition is significantly altered with increased fat and decreased muscle volume as compared to healthy subjects. Epidemiological data suggest premature mortality from cardiovascular disease. Short-term GH treatment trials have shown improved psychosocial performance, normalization of body composition, increased muscle strength, improved exercise capacity, and increased cardiac performance. (Christiansen & Jorgensen, Univ Dept of Endocrinology and Int Med, Aarhus Kommunehospital, Denmark) X In a recent study, administration of synthetic growth hormone to elderly male patients to normalize their low HGH levels resulted in significant muscle gain and fat loss. X A Dutch study 8 GH deficient patients reported that 6 months GH therapy increased lean body mass and decreased fat mass. The sense of well-being improved in most patients. Cholesterol levels decreased. (Clinical Endocrinology 1992 37, 79-87) X A study at St. Thomas' Hospital in London found that patients with hypopituitarism have altered body composition and quality of life. In comparison with a matched control group such patients had considerably reduced lean body mass and increased fat mass and waist to hip ratio. A number were significantly depressed, sufficient to justify therapy. "We conclude that there is a morbid syndrome associated with growth hormone deficiency in adult life which responds dramatically to hormone replacement. To be effective this therapy has to be continued indefinitely." X Exogenous GH increases lean tissue and reduces body fat in obese women in the absence of significant energy restriction. (Hormone Research 1991, 19-24) X Obese men manifest fewer GH secretory bursts per 24 h and accelerated HGH disposal rates. (Journal of Clinical Endocrinology and Metabolism 72:1 p. 51) X In the future, high risk babies might be given lipid tolerance tests, and pre-obese individuals treated with HGH and DHEA to keep them from becoming fat. X X X X X X X X X X X Adiposity 101 67 3-9-93 X X X HGH may be useful in reducing diet-induced loss of lean tissue. X 11.2.1 Growth Hormone Stimulation Human growth hormone is expensive, and side effects are an issue. An alternative to HGH injection is to stimulate the body to excrete HGH. X Pearson and Shaw recommend stimulation of human growth hormone (HGH) excretion with arginine amino acid supplements as a weight loss method. Unfortunately, the references given in their book indicate their recommended amino acid megadosage is still orders of magnitude too small to cause the obese to release detectable amounts of HGH. X The obese have a high threshold which must be surpassed by strenuous exercise (to the point of exhaustion) or "incredible" doses of amino acids (orders of magnitude more than even Pearson&Shaw recommend) before any stimulation of HGH release is noted. HGH levels achieved under these exceptional conditions are still only a fraction of what lean subjects spontaneously produce in their sleep. X The antiobesity drug fenfluramine normalizes obese subjects' human growth hormone (HGH) response to arginine. (Hormone Research 1987: 27; 190-194) X X Long term propranolol therapy increases body weight in heart attack patients (2P-14); this may modify some of Pearson and Shaw's recommendations. X "Chronic ingestion of L-dopa (an HGH releaser) leads to sustained but reversible weight loss in both lean and obese Zucker rats." X 11.3 DHEA TREATMENT X Dehydroepiandrostone (DHEA) reduces weight gain in the hypercorticosteronemic Zucker fatty rat, an animal of genetic obesity. Its chronic anti-obesity effect is thought to reflect a chronic antiglucocorticoid activity. (Int J of Obesity, 1992, 579-) X University of Wisconsin researchers treated normal and 19 spontaneously obese dogs with DHEA. The normal weight dogs did not reduce weight or energy intake. Two-thirds of the obese dogs lost 20 percent of their excess body weight and dropped cholesterol levels by nearly 25 percent without reduction in food intake. (Int J of Obesity 1990, 14,95- 104) X X X X X X X X X X X X Adiposity 101 68 3-9-93 X X X The 1990 Journal of Nutrition reported that DHEA treatment reversed dietary induced obesity (from a mixture of corn oil and condensed milk) as well as genetically induced obesity (fa/fa rat). X In premenopausal obese women, DHEA levels are inversely proportional to BMI. Adipose cells remove DHEA from the bloodstream; enhanced removal of DHEA in severely obese may account for their impaired sensitivity to caloric restriction. (Metabolism, Feb 91, p 187) X Pearson & Shaw claim the "DHEA" sold by health food stores is bogus. The author of "The Vitamin Bible" reports successful personal weight loss with DHEA but gives no sources or details. X 11.4 RU-486 TREATMENT X @RU-486 completely reversed the obesity of genetically obese (fa/fa) rats by blocking the effects of glucocorticoids and insulin causing excessive fat cell proliferation. RU-486 reduced fat storage from 1907 kj to 102 kj, while increasing protein (lean tissue) storage from 44 kj to 217 kj. (American Journal of Physiology 1990, R539-43) X RU-486 (mitepristone) reduces the deposition of fat tissue and increases the deposition of lean tissue, but only in obese subjects. RU-486 also causes obese mice to lose weight by increasing BAT thermogenesis. Reportedly RU-486 can help cure Cushing's syndrome, a gland disorder characterized by obesity and hypertension. "Potentially the most potent anti-aging drug available." (Longevity, Jan 1991) X A paper in the 1992 International Journal of Obesity reports that Norepinephrine (the neural transmitter, not the asthma drug) inhibits rat pre-adipocyte proliferation. X X X X X X X X X X X X X X X X X X X X X X X X X Adiposity 101 69 3-9-93 X X X 11.5 CoPP TREATMENT X The 1990 Pharmacology reported that injections of cobalt- protoporphyrin completely reversed the obesity of Zucker fa/fa fatty rats. Unlike diets, lean tissue is not affected. Untreated rats that were fed the same amount of food as the CoPP treated rats for the first 42 days reverted to the same weight as untreated fatty rats by day 60. This indicates CoPP caused a long term reduction in the rats' set point. X #X#8O8##TILH#8OIi=L=;+;;=i;iX=88i88X#;XT;;8X;X)==;+;;=+++++++++++++++++++++++++ #####+Li8i#)i);=+O+==;;;;+;+;+==I=L+=+I##;=8iO###8X;HiX888888;;+;;;;;;888888IL+ ###O####)#8I#)####i#+;;;;i=8#8####O######II))######8)i;;=+;=+;+;+;;+;;=;;++I+++ ###L###############TT:#X##X=##X#=#IO#OH##i#+=#8##+ ;=88I88+ #########=####H#8I= ###T==######O8X###=OTH#X) 88+ ####L#=####88##I+i ;###O#L8##L#T##8O#O8II;+ ;:+ ##8#XH##########= =Xi#XO#=##O#=###)==#+: +:+ ##I##8+#I######= ;=L#;I+T#i8O#;###H;I + #########L=###X ;##I##=#8#I8OT#+## ;+ #######X#8#X##L :I8IL#+O+=#8X;#iX##X ::+ #==T#8####L##++ ;L8I#I#IH###Xi;L8X8I ;+ #####L#=;##H :#II8I8I*x#+##XO#;8# ;+ ######88i#= ;=II8I8I8I+;+ ;: =; #IL #8#+#####8 :XXI8I8I8;i#;X8;8O: +; ;X#;8 ####=O##8 :#XI8I8I88#H;8# 8=8Oi #8XT= ###=+88X: #XI8I8Ii 8=+HX=#X#OH+;# ;: ;+ ;+ ;=;##8;8 ##8HO#= #XI8I8II8+XL) 88X+X=;+8;O;I+H;8 : ;: ;II;XX##X;8 #I;== ,#X8HX8X**X*X*X 8 XI;==#;8;iO: L ;=XO=888X;L;Oi88888 ##### =L###XXIiX+T X ;XI88;=;=;I: ;+ ;+H=ITiO8;+;IL;X8;i8;8; ####### ;X#I=#H=X;LI8;=;88i XX;88 :::;+;L;=X=T)T;+;=8;8888=+L=88 ########## #X=#X=ILL#I#8;8L;=L+ + L+OI THO ;O +;8=;);=i X8L8;X8H= IL8 #############X=#X=#IL#8###########THHX H;I+;O 8,8)=;iH+=L;T888+=Hi;8);8X;=X ##=8=i#=88+i;=L;I;IX)+=;8=)8iL8+;+;;O;#i;#XO;8X8;;;=O==I==H=LT=8=+;X+;H+===++;= X Typical CoPP treated (left) and untreated (right) Zucker fatty rats. Look at this from a distance to get the best effect. (B/W Xerographic photocopy of original color plate was scanned, converted to GIF format by XView, converted to ASCII with ASCGIF.) X 11.6 CIRCADIAN LIPOSTAT MANIPULATION X Some obesity and type II diabetes may be caused by defective circadian [daily cycle] neuroendocrine rhythms. X Albert Meier, professor of zoology at Louisiana State University, initiated a study of bromocriptine after 25 years of research on animals' body rhythm biology during migration and hibernation. What he attempted to translate to humans was the finding that many animals reduce or X X X X X X X X X X X Adiposity 101 70 3-9-93 X X X increase their body fat without altering food intake or activity levels. (Insight, Mar 26 1990) X Meier, Cincotta and Lovell have dramatically reduced body fat with oral bromocriptine taken orally at times calculated to reset circadian hormone rhythms to phase relationships that cause loss of body fat. Bromocriptine is a dopamine agonist used to suppress lactation and in treatment of Parkinson's disease. X "The phase of the prolactin rhythm differs in lean and fat sparrows, fish, rats, and humans. Daily injections of prolactin in animals at times when the daily peaks occur in the plasma of lean and fat animals produce the appropriate decrease or increase in fat stores within two weeks." X In early clinical trials, without food restriction, body fat was reduced equivalent to a 420 calorie VLCD, but without the loss of lean body mass caused by weight loss diets. Studies with Syrian hamsters investigating whole body protein turnover indicate this treatment enhances protein synthesis, redirecting anabolic activities from lipid to protein. Apparently the timed bromocriptine treatment alters the genetically controlled partitioning of nutrients described in "The response to long-term overfeeding in identical twins" discussed above. X In the second study reported in Experientia 48 (March 1992 p. 248-), 15 diabetic subjects were given timed bromocriptine treatment. As with the non-diabetic subjects, all 15 diabetic subjects lost fat.6 Blood glucose dropped significantly. Oral hypoglycemic medication was was discontinued in 3 participants, and glucose levels remained near normal for at least two months after treatment. Doses of hypoglycemic drugs and insulin were reduced in three X X __________ X X 6. That *all* subjects lost fat is significant. In energy X deprivation diet studies, some subjects invariably fail X to lose weight. In long term diet followup, the X standard deviation is two or three times as great as the X average weight loss because a large minority gain X weight, sometimes a great amount. Without individual X data or the standard deviation, one simply cannot judge X the true effectiveness of the experimental intervention. X Many diet studies suppress this information as it would X cause the reader to discount the validity of the claimed X results. X X X X X X X X X X X X Adiposity 101 71 3-9-93 X X X other subjects during treatment. X Blood pressure was also reduced, allowing blood pressure medication to be discontinued in several. X In a telephone conversation (June 1992) Dr. Meier reported that a third series of clinical trials was underway as part of the FDA process to approve the treatment as safe and effective. He strongly emphasized how critical TIMING is to fat loss; correct dosage given in the wrong rhythm actually increases body fat. The timing calculation is a process patented by Louisiana State University and licensed to Ergo INC, Newport RI. Drs. Meier and Cincotta have financial interest in the process. X "Our studies also indicate that a cause-effect relationship between overfeeding and obesity is oversimplistic and that food intake and lipid synthesis may be regulated in a concerted fashion by circadian neuroendocrine activities." X 11.7 TESTOSTERONE TREATMENT X @ Testosterone has been shown to decrease adipose tissue mass by several mechanisms. Young men with high testosterone secretion have low visceral fat mass. Men with abdominal obesity have low testosterone values and insulin resistance. X An 8 month study at the Sahigren's Hospital in Goteborg, Sweden tested 23 men aged 40-65 years in a fully controlled, double blind experiment in restoring testosterone levels to normal. The testosterone treated group improved in waist size, blood pressure, plasma lipids, fasting glucose, and insulin sensitivity. The treated group reported improvements of well-being and energy. Normalization of testosterone levels reduced many of the health warning signs associated with obesity. No adverse functional side-effects were found. (International Journal of Obesity 1992 16:991- 7) X 11.8 BETA3-ADRENOCEPTOR AGONISTS X Animal studies on several Beta3-agonists show they fulfill many of the properties of the ideal anti-obesity drug. These compounds produce selective loss of body fat mass with a preservation of lean tissue. In addition, the changes in body composition are accompanied by favourable metabolic changes including improvement in glucose tolerance, reduction of hyperinsulinemia and hyperlipidaemia. (S18-3) X X X X X X X X X X X X X Adiposity 101 72 3-9-93 X X X 11.9 SEROTONIN REUPTAKE INHIBITORS X "The genesis of this project was an invitation to discuss anorexiant medications with the house officers in the Medical Clinic as Strong Memorial Hospital. The colleague who invited me was dismayed that the treatment options used in the medical clinic were not helping people lose weight." Michael Weintraub, MD "both the medical profession and society look with disfavor on obese people and obesity in general. ... Obese people are treated negatively in cartoons and in literature. Many believe that obese people need only to "close their mouths" and be more motivated to lose weight. The use of medications to correct a characterologic defect is, in the opinion of physicians and the public, deemed inappropriate. X Unfortunately, a lack of understanding of both the natural history of obesity and its diversity adds to the perjorative view of obese people and of anorexiants. Some health professionals are not aware of data concerning mechanisms present in the human organism that act to contravene perturbations in body weight and that may account for the apparent failure of interventions, including medications." X To provide longer-term data, Weintraub et al developed a 4 year multimodal program using state-of-the-art behavior modification, caloric restriction, and exercise as the "placebo" for the entire duration of the four year study. Subjects attended nearly 100 visitations with health professionals during the study. When reading reports on The National Heart, Lung, and Blood Institute funded Multimodal Intervention Study, please keep in mind that this "state- of-the-art" treatment was the "placebo". (State of the diet/exercise/shrink art, that is!) "From the end of the second double-blind phase at week 190 through week 210, we monitored study participants to see what happened without medication but with continuing behavior modification, caloric restriction, and exercise therapy. ... One measure of the excellence of the ancillary [placebo] therapy in this study was that it enabled participants treated with placebo to lose just 0.01 kg/week less than participants receiving active therapy in the 18 studies that lasted at least 8 weeks reviewed by Scoville for the FDA." X 121 subjects, 18 to 60 years old, mean BMI of 33.4 +- 2.2, three fourths female, entered the medication phase of the study after 6 weeks of behavior mod, diet and exercise. 69 per cent had been on six or more diets previously. X Subjects on medication lost about three times the weight as those only receiving behavior modification, diet and X X X X X X X X X X X Adiposity 101 73 3-9-93 X X X exercise. There was no indication of tolerance or abuse potential of the medication. There was no indication that use of anorexiant inhibits the learning of behavior modification. X As reported by the New York Times New Service, Dr. Albert Stunkard, an obesity researcher at the University of Pennsylvania, said he knew of no other study that had elicited such a dramatic and sustained weight loss. It ``points to the way things are going to go,'' he said. X The investigators found their patients could not maintain their weight loss without the drugs. X The final 30 weeks of the program assessed what happened when all the patients were weaned from the drugs, relying on continued diet, exercise and behavior control. They gradually regained almost all the weight they had lost, despite the continuing program of diet, exercise and behavior modification. X Some who believe that the essential defect in obesity is will power have asserted that the weight regain was from subjects' going "off the diet" when medication was withdrawn, instead of the diets' poor long term performance. A number of facts argue against this assertion: X X + Fenfluramine's appetite reducing effect wears off X within a week. Any increased eating from cessation of X the anroectic effect would have occurred much earlier. X X + Patients were on moderate diets, up to 1800 X calories/day for men, 1200 for women. Most of the X patients were veterans of a half dozen or more diet X attempts. With this amount of metabolic slowdown, the X traditional (diet/exercise/behavior mod) part of the X program may not have been able to induce much long-term X weight loss without benefit of the drugs' lowering of X set point. X X + Lipid profiles, primarily affected by the diet and X exercise, confirmed the weight regain was not caused by X cheating on the diet. X When the study was over, and subjects taken off the drugs were nearly as fat as they were initially, many tried to get the drug combination from their private doctors and ran into skepticism over the treatment. X Some experts on weight loss hailed the studies, saying they could mark a pronounced shift in the way obesity is studied X X X X X X X X X X X Adiposity 101 74 3-9-93 X X X and treated. X These experts said the results showed obesity could be treated the way chronic diseases like high blood pressure or arthritis are. In those diseases, drugs must be taken indefinitely to keep symptoms in check. X ``This is a landmark study,'' said Dr. George Blackburn, an obesity researcher at New England Deaconess Hospital in Boston, author of the 1989 paper "Weight cycling: the experience of human dieters". X Study VI of the report discusses individual outcomes. One subject did not reach goal weight (120% of ideal) but he was able to maintain his weight loss even after medication ceased. Some others did reach goal weight but gained it all back, or more. Most lost at least some weight but regained after medication ceased, despite continuing behavior modification, diet and exercise. Some lost little or no weight, or gained weight. Many of the failures were due to the experimental protocol which did not allow for individual adjustments that would have been made in a health care setting. Diet evangelists who do not appreciate the deep biological diversity of fat people should study this paper (and the papers on identical twins) carefully. X X Serotonin-reuptake inhibiting agents include flouxetine (Prozac), fenfluramine, and d-fenfluramine (dexfenfluramine, dF). X In France and England, fenfluramine has been used in the treatment of human obesity for 25 years. No unequivocal report of major health hazards has appeared with fenfluramine in spite of extensive worldwide prescription for decades. Dexfenfluramine is the dextro stereoisomer of fenfluramine, and is a more potent antiobesity agent with fewer side effects. Tiredness and drowsiness were the most commonly reported unwanted side effects of treatment, but occurred as frequently with placebo treatment as with dexfenfluramine." (Clinical Neuropharmacology Vol 11 Suppl 1 S179) X Over five million people have benefited from dexfenfluramine over the past seven years. "It's proven itself over and over again." (Dr. Rudolf Noble, Dir. Cathedral Hill Obesity Clinic, San Francisco) X X The conventional characterization of d-fenfluramine as an appetite suppressant is hopelessly oversimplified at best, X X X X X X X X X X X Adiposity 101 75 3-9-93 X X X if not downright inaccurate. "According to most authors, tolerance to the anorectic effects of d-fenfluramine in rats rapidly sets in; food intake is depressed or only 2 to 6 days ... However, as long as the drug is administrated, the weight deficit persists." (Clinical Neuropharmacology Vol 11 Suppl 1 S105) X "Following approximately a week of daily ingestion of fenfluramine, the body weight of female rats is reduced and remains chronically suppressed for as long as treatment is continued. This chronic suppression of body weight by fenfluramine cannot be explained by the anorectic effects of fenfluramine, since food intake returns to normal after about a week. Part of this chronic suppression of body weight lies in the ability of fenfluramine to enhance the thermic effect of food. Fenfluramine ingested by a fasted rat causes no change in metabolic rate. However, following the ingestion of the meal consisting of mixed nutrients or only carbohydrates, the thermic effect of the food is significantly greater than that of the meal without fenfluramine. A similar observation was observed in humans. These observations when combined with the negligible effects of dieting as a means of controlling body weight, argue for the chronic use of fenfluramine as a therapeutic technique to produce sustained weight loss in humans." (Clinical Neuropharmacology Vol 11 Suppl 1 S90-2) X Is fenfluramine's anorectic effect essential to its antiobesity properties? When body weight was reduced in rats prior to treatment with fenfluramine, administration of the drug was followed by a rapid increase in food intake with maintenance of the reduced weight. The reduced body weight in fenfluramine-treated rats is defended; when animals are force fed to a higher weight and then allowed to eat ad libitum their food intake drops and body weight drops. (Recent Advances in Obesity Research: V 290) X Fenfluramine normalizes obese subjects' human growth hormone (HGH) response to arginine. Normally obese subjects generate negligible amounts of HGH in response to arginine stimulation. (Hormone Research 1987: 27; 190-194) X Fluoxetine, another serotonin-reuptake inhibiting agent, has been shown to improve insulin sensitivity and other metabolic actions. X Dexfenfluramine is a related drug that increases metabolic rate (MR), diet induced thermogenesis (DIT), decreases blood pressure, and enhances glucose clearance. Dexfenfluramine reduces or prevents weight regain after slimming. The drug appears well suited for use in hypertensive or diabetic X X X X X X X X X X X Adiposity 101 76 3-9-93 X X X obese patients. (Clinical Neuropharmacology Vol 11 Suppl 1) (Progress in Obesity Research 1990) In rat, d-fenfluramine improves insulin action of reducing the liver's glucose output. (DIABETES Apr 1989) X The Weintraub study maintains a level of experimental design, reportage, disclosure and honesty that distinguishes it from most studies of traditional weight loss techniques. It is the longest weight control study of any type. It underscores the abject failure of traditional weight loss technology to improve the quality of life for most fat people. X Free reprints of this 65 page supplement are available. X Numerous papers on the antiobesity properties of serotonin- reuptake inhibiting agents appeared in Vol 11 Supplement 1 of Clinical Neuropharmacology (1988). X 11.10 FAT CELL REMOVAL X 11.11 Surgery X Surgery is the only currently available fat reduction treatment that has demonstrated long term success in a majority of patients. X Unfortunately, the amount of fat removed by currently accepted surgical procedures is too small to be useful for mainstream weight reduction purposes. X A newspaper recently reported an increase in breast size for women who had "love handles" removed. It is possible the breast size was recovering from the effects of stringent dieting undertaken in unsuccessful attempts to spot reduce the "love handles". X A South African study of freely-eating, non-obese liposuction patients showed no increase in fat cell size, metabolic efficiency, or regional adipose distribution 1 to 2 months after surgery. X Surgical removal of fat in Cushing's Syndrome patients (4F- 21) resulted in an increase in lean tissue mass, and no fat regain. X Diabetic patients receiving abdominal liposuction have reduced insulin requirements (dose reduced from 20 to 10 units). (Unpublished data) @ By 1995 obese Type II diabetics will be treated with liposuction. This procedure is intended to lower the need for insulin by reducing the X X X X X X X X X X X Adiposity 101 77 3-9-93 X X X total number of fat cells in the diabetic's body. (Longevity Jan 1993; Fred Glazer M.D.) X Some efforts are underway to develop surgical procedures to significantly normalize fat cell numbers. X 11.12 Immunological Manipulation X The Hannah Research Institute in Scotland have developed a treatment to reduce adiposity by targeting cytotoxic antibodies to fat cells. In early experiments, rat fat cell plasma was injected into sheep. The resultant antibodies were filtered and introduced into the rats. The treated rats lost fat. X The treated rats also had more lean tissue than untreated controls. This suggests fat cells deprive lean tissue of nutrients necessary for growth. X After treatment ended, the rats gained fat in other areas, restoring a normal amount of fat. This suggests some higher level mechanism prevents adipose mass from falling below norms. Normal weight rats were used in these experiments; results may be better for obese humans with diet induced adipocyte hyperplasia. X In a 1991 telephone conversation this author was told Hannah's research is proceeding very well toward its goal of producing leaner animal meat. Human application in the near future was thought unlikely due to risk of malpractice lawsuits. X Other researchers, using monoclonal antibodies, report success in longer term suppression of fat cell numbers. (Private conversation, 1992) X X 12. PREDICTIONS X Some of the current obesity epidemic will be traced to nutritional and hormonal problems during pregnancy and/or infancy. Pregnancies with gestational diabetes and other problems that previously failed now produce preobese children. The introduction of high carbohydrate baby formula and sugary baby foods in this century will also be a factor. Weight loss diets applied early in life will also be implicated. X Within the decade, prescription of energy restriction weight loss diets for patients with childhood onset obesity will be recognized as a violation of the Hippocratic Oath. X X X X X X X X X X X Adiposity 101 78 3-9-93 X X X 13. RECOMMENDATIONS FOR ACTION X Popular attitudes on obesity are based on the notion that obesity is caused by sloth and gluttony. Recent research has discredited this stereotype and suggested possibilities for effective prevention or treatment in the future. X X + Truth in Advertising must be enforced on all weight