4 questions | Applied Sciences homework help

1. Jenkins L. Naturopathic technique stirring bad blood. San Diego Tribune, April 11, 2005.

Weight Control Americans brought up in a society full of technological miracles are constantly searching for the easy way out. In desperation, they are willing to try anything offered to them, wasting money, time and sometimes their own lives. GeorGe L. BLackBurn, M.D., Ph.D. konstantin PavLou, sc.D.1 Diets usually leave a person aggravated, discouraged, and the same size. aMy Lanou, Ph.D.2 Q. Can a diet pill really cause people to lose fat while they sleep? A. If it worked you would be reading about it in the headlines of every newspaper in the country. ann LanDers © medical economics, 1992 “It doesn’t look that scary to me, either. But my Mom won’t even go near it.” Chapter Twelve Part Three Nutrition and Fitness234 In 2010 Americans spent about $61 billion for products and services they hoped would en- able them to control their weight.3 Much of this money was wasted. The following observation, made in 1972 in the AMA’s Today’s Health4 magazine, is still appropriate today: They will attend reducing clinics and join reducing programs. They will visit doctors who will write weight-reducing pre- scriptions for them and inject them with hormones. They will enter hospitals for fat-removing operations. They will get themselves hypnotized, and psychoanalyzed individually and in groups. They will purchase books and pamphlets extolling the virtues of high-calorie diets; low-calorie diets; high fat, carbohydrate and/or protein diets; low-fat, carbohydrate and/ or protein diets; grapefruit diets; water diets; drinking men’s diets; organic food diets; and sex-instead-of-supper diets. They will gulp down diet pills, blow on diet soups, chomp on diet cookies and chew on diet gum. Most of the time, for a variety of legitimate reasons, they will emerge in much the same condition as when they began: fat. And much of the time, for a variety of illegitimate reasons, they will also emerge defrauded. This chapter describes the basic principles of weight control and the various types of products, procedures, and professional services used in the attempt to achieve it. Included in this discussion are diets, pills, special foods, and gadgets, as well as medical, surgical, and psychologic procedures, clinics, and self-help groups. For additional information on exercise, exercise devices, and “spot-reducers,” see Chapter 13. BasiC ConCepts The words obese and overweight are often used in- terchangeably. Strictly speaking, obesity refers to an excess accumulation of fatty tissue in the body, whereas overweight refers to a weight greater than that listed in an established height-weight table (Table 12-1). These terms are not mutually exclusive because obese persons are also overweight. The National Institutes of Health (NIH) guidelines use body mass index (BMI) to classify weight status. The BMI is the person’s weight in kilograms divided by the square of the person’s height in meters. It can also be calculated by multiplying one’s weight in pounds by 700, dividing the result by one’s height in inches, and dividing by height again. The guidelines classify adults 18 and older into six groups: underweight (BMI less than 18.5), normal (18.5–24.9), overweight (25.0–29.9), Class I obesity (30.0–34.9), Class II obesity (35.0–39.9), and Class III (extreme) obesity (40 or more). People with a BMI of 40 or more are commonly referred to as morbidly obese. Table 12-2 illustrates representative BMI values. BMI calculators are available on many Web sites, includ- ing www.nhlbisupport.com/bmi/bminojs.htm. The causes of obesity are multiple and complex; they include glandular abnormalities (rarely), heredity, improper eating habits, insufficient physical activity, and psychosocial problems. Americans generally are getting heavier. Based on data from the 2007–2008 National Health and Nutrition Examination Survey (NHANES), experts have estimated that 73% of adults ages 20 to 74 are overweight or obese, up from about 47% in 1976–1980, 56% in 1988–1994, and 65% in 1999–2002.5 During the same period, the prevalence of overweight also rose from 5% to 10% in children ages 2–5, 7% to 20% among children ages 6–11, and from 5% to 18% among adolescents ages 12–19.6 Most people who are overweight are overfat (obese). However, some individuals—particularly muscular young men—can exceed the listed weight without being overfat. Thus it is more precise to use the term overfat when referring to someone whose weight is too high because of excessive body-fat content.

• The most sensible weight-loss plans aim for a steady reduction of about 1 pound a week.
• Mail-order products claimed to produce rapid or permanent weight loss are scams.
• Fad or “crash” diets rarely have a permanent beneficial effect.
• To lose weight safely and keep it off, people must make long-term changes in their eating and exercise habits.
• Commercial weight-loss programs are expensive and have demonstrated little evidence of long-term effectiveness.
• Many people concerned about their weight would probably do better to focus on exercise and healthful eating rather than on counting calories.

Keep these points in Mind as You studY this Chapter Key Concepts Chapter Twelve Weight Control 235 Body fat can be estimated with fair accuracy by measuring the thickness of various skin folds with one’s fingers or a special skin caliper. More accurate methods include underwater weighing, ultrasound, electromag- netic methods, bioelectrical impedance, CT scanning, neutron activation, and nuclear magnetic imaging, but these are expensive and used mainly for research pur- poses. A rough indication of excessive body fat can be obtained by pinching the flesh on the back of the upper arm, midway between the shoulder and the elbow. Men who can pinch 1 inch or more and women who can pinch more than 11/4 inches are probably overfat. Perhaps the most practical method is to remove one’s clothes and look into a full-length mirror. The Desirable Weight Table (see Historical Perspec- tive box) offers yet another assessment tool. Health Risks of Obesity Tens of millions of Americans have too much body fat. Small degrees of overfat are not harmful, but being 20% overfat is clearly a health hazard.7,8 The life expectancy of Americans has risen steadily during the past two cen- turies, but Olshansky9 and others have expressed concern that this trend will soon come to an end. The most serious problem associated with being overfat is high blood pressure, but there are also consid- erably increased risks of sickness or death from diabetes; gallstones; liver, kidney, heart, and blood vessel diseases; osteoarthritis; and other problems. Overweight is also a contributing cause of sleep apnea, a common disorder in which the affected individual has pauses in breathing during sleep.10 The health significance of body fat can be esti- mated by using the BMI. Overweight carries a slightly increased risk for weight-related health problems, but obesity (BMI of 30 or more) entails serious health risks.11 Obese men tend to accumulate abdominal fat, whereas women tend to accumulate fat on their hips and thighs. A waist-to-hip ratio (WHR) greater than 1 indicates a high risk of adverse health consequences. WHR is determined by dividing the circumference of the waist by the circumference of hips. The waist is measured at the level of the navel (belly button), and the hips are measured at the area of maximum protrusion of the buttocks. A man with 35-inch hips and a 42-inch waist, for example, would have a WHR of 1.2. With respect to health risks, the location may be more important than the total amount of body fat. In men a high WHR is associated with elevated blood- cholesterol levels and increased risk of coronary artery taBle 12-1. desiraBle Weights, ages 25 and older 5’–2” 112–120 118–129 126–141 5’–3” 115–123 121–133 129–144 5’–4” 118–126 124–136 132–148 5’–5” 121–129 127–139 135–152 5’–6” 124–133 130–143 138–156 5’–7” 128–137 134–147 142–161 5’–8” 132–141 138–152 147–166 5’–9” 136–145 142–156 151–170 5’–10” 140–150 146–160 155–174 5’–11” 144–154 150–165 159–179 6’–0” 148–158 154–170 164–184 6’–1” 152–162 158–175 168–189 6’–2” 156–167 162–180 173–194 6’–3” 160–171 167–185 178–199 6’–4” 164–175 172–190 182–204 4’–10” 92–98 96–107 104–119 4’–11” 94–101 98–110 106–122 5’–0” 96–104 101–113 109–125 5’–1” 99–107 104–116 112–128 5’–2” 102–110 107–119 115–131 5’–3” 105–113 110–122 118–134 5’–4” 108–116 113–126 121–138 5’–5” 111–119 116–130 125–142 5’–6” 114–123 120–135 129–146 5’–7” 118–127 124–139 133–150 5’–8” 122–131 128–143 137–154 5’–9” 126–135 132–147 141–158 5’–10” 130–140 136–151 145–163 5’–11” 134–144 140–155 149–168

M E N

W o M E N Medium Frame Large Frame Small Frame Height in Shoes Weight in Pounds Weights are obtained in indoor clothing, with men wearing shoes with 1-inch heels and women wearing shoes with two-inch heels. The data are based on weights associated with lowest death rates. For adults younger than 25, subtract 1 pound for each year under 25. An article at www.halls.md/ideal-weight/met.htm) indicates how to determine frame size and provides additional historical information. Historical Perspective The “Desirable Weight” Table12 The concept of the height-weight table was developed many years ago by Louis Dublin, a Metropolitan Life Insurance Company statistician. After grouping policyholders by age, height, and weight, he found that those who lived longest were the ones who maintained their weight at the average level for 25-year-olds. Because Dublin felt that there was no “ideal” weight for all individuals, he called these ranges “desirable weights.” The table below lists the “desirable weights” he proposed in 1959 for adults ages 25 and older. Some statisticians have criticized these weights because they involved only individuals who had qualified for life insurance and mainly reflected data from upper-middle-class white groups. But many authorities believed they were still the best figures relating weight to life expectancy.13 Part Three Nutrition and Fitness236 4’–10” 96 100 105 110 115 119 124 129 134 138 143 167 191 4’–11” 99 104 109 114 119 124 128 133 138 143 148 173 198 5’–0” 102 107 112 118 123 128 133 138 143 148 153 179 204 5’–1” 106 111 116 122 127 132 137 143 148 153 158 185 211 5’–2” 109 115 120 126 131 136 142 147 153 158 164 191 218 5’–3” 113 118 124 130 135 141 146 152 158 163 169 197 225 5’–4” 116 122 128 134 140 145 151 157 163 169 174 204 232 5’–5” 120 126 132 138 144 150 156 162 168 174 180 210 240 5’–6” 124 130 136 142 148 155 161 167 173 179 186 216 247 5’–7” 127 134 140 146 153 159 166 172 178 185 191 223 255 5’–8” 131 138 144 151 158 164 171 177 184 190 197 230 262 5’–9” 135 142 149 155 162 169 176 182 189 196 203 236 270 5’–10” 139 146 153 160 167 174 181 188 195 202 207 243 278 5’–11” 143 150 157 165 172 179 186 193 200 208 215 250 286 6’–0” 147 154 162 169 177 184 191 199 206 213 221 258 294 6’–1” 151 159 166 174 182 189 197 204 212 219 227 265 302 6’–2” 155 163 171 179 186 194 202 210 218 225 233 272 311 6’–3” 160 168 176 184 192 200 208 216 224 232 240 279 319 6’–4” 164 172 180 189 197 205 213 221 230 238 246 287 328

BMI: 20 21 22 23 24 25 26 27 28 29 30 35 40

BodY Mass index (BMi) Table 12–2 Height Weight (Pounds) Find your height in the left column and move across to the column containing your weight. The bold number at the bottom of the column is your BMI (your weight in kilograms divided by the square of your height in meters). disease, high blood pressure, and adult-onset diabetes. These problems are related more to fatty tissue located inside the abdominal cavity than to fatty tissue located just under the skin. Preventing obesity during childhood may lower the chance of obesity in adult life.14 Unfortunately, the rates of obesity among American children and adolescents are high and have been increasing steadily.6 Difficulty with “Dieting” The two basic factors involved in weight control are caloric intake and energy expenditure. To lose weight one must eat less or exercise more—but most people need to do both. There are about 3500 calories stored in 1 pound of body fat. Most moderately active people need about 15 calories per pound to maintain their weight (see Table 12-3). To lose 1 pound of fat per week, one must consume an average of 500 fewer calories per day than are metabolized. Nutritionists recommend against using diets under 1200 calories per day without medi- cal supervision. Table 12-4 shows how caloric deficit is related to the rate of weight loss. Most people who are overfat find weight control difficult or impossible to achieve. Long-term studies of overfat individuals—done mainly in hospital clinics— have found that more than 95% of those who lost weight approxiMate CaloriC intaKe ModeratelY aCtive people need to Maintain Weight Table 12–3 Weight Daily Calories Needed 100 1500 110 1650 120 1800 130 1950 140 2100 150 2250 160 2400 170 2550 180 2700 190 2950 200 3000 Chapter Twelve Weight Control 237 by dieting regained it within 1 year. Dietary treatment is most likely to succeed in people who are only modestly overweight. Obese individuals tend to “burn” calories more slowly. They tend to be less active, which com- pounds the problem, because people tend to eat more when they are sedentary. They also tend to underestimate the number of calories they eat15,16 and to underreport their weight and overreport their height.17 Table 12-5 discusses common myths about weight control. The Institute of Medicine11 has defined successful dieting as a 5% reduction in initial body weight that is maintained for at least 1 year. Evidence is accumulating that heredity may be the major predisposing factor in determining how much people weigh. When people deviate from their usual weight, metabolic adjustments tend to oppose the change. Researchers have found, for example, that significant weight loss is accompanied by increased hunger and a decrease in the body’s metabolic rate.18 Bennett19 has noted that the weight-control measures are not hopeless because people’s “fat thermostat” may be reset if they consume less fat and increase their habitual level of physical activity. Some studies suggest that weight cycling (repeated weight loss through dieting followed by weight gain) may increase the risk for high blood pressure, high cho- lesterol, and gallbladder disease. However, the National Task Force on the Prevention and Treatment of Obesity20 concluded that the majority of studies published between 1966 and 1994 did not conclusively show that weight cycling is harmful. The task force stated that signifi- cantly obese individuals should not allow concerns about hazards of weight cycling to deter them from trying to control their weight. Because “dieting” is usually unsuccessful, many experts believe that people’s emphasis should be on fit- ness (readily attainable through exercise) and control of cardiovascular risk factors (abnormal blood cholesterol levels, high blood pressure, and elevated blood sugar levels). For example, the participants in a 1992 NIH Technology Assessment Conference21 concluded: Methods whose primary goal is short-term rapid or unsu- pervised weight loss, or that rely on such diet aids as drinks, prepackaged foods, or pharmacologic agents but do not include education in and eventual transition to a lasting program of healthful eating and activity, have never been shown to lead to long-term success. It has been fairly said that such programs fail people, not vice-versa. Recognition of this by society and individuals and a focus on approaches that can produce health benefits independently of weight loss may be the best way to improve the physical and psychological health of Americans seeking to lose weight. The panelists also concluded: “A health paradox ex- ists in modern America. On the one hand, many people who do not need to lose weight are trying to. On the other hand, most who do need to lose weight are not succeeding.” Abernathy and Black22 stated that more emphasis should be placed on risk factors and healthy lifestyles and less on height-weight tables and body-fat percentages. 100 200 300 400 500 600 700 800 900 1000 1100 1200 1 5.0 2.5 1.7 1.3 1.0 0.8 0.7 0.6 0.6 0.5 0.5 0.4 2 10.0 5.0 3.3 2.5 2.0 1.7 1.4 1.3 1.1 1.0 0.9 0.8 3 15.0 7.5 5.0 3.8 3.0 2.5 2.1 1.9 1.7 1.5 1.4 1.3 4 20.0 10.0 6.7 5.0 4.0 3.3 2.9 2.5 2.2 2.0 1.8 1.7 5 25.0 12.5 8.3 6.3 5.0 4.2 3.6 3.1 2.8 2.5 2.3 2.1 6 30.0 15.0 10.0 7.5 6.0 5.0 4.3 3.8 3.3 3.0 2.7 2.5 7 35.0 17.5 11.7 8.8 7.0 5.8 5.0 4.4 3.9 3.5 3.2 2.9 8 40.0 20.0 13.3 10.0 8.0 6.7 5.7 5.0 4.4 4.0 3.6 3.3 9 45.0 22.5 15.0 11.3 9.0 7.5 6.4 5.6 5.0 4.5 4.1 3.8 10 50.0 25.0 16.7 12.5 10.0 8.3 7.1 6.3 5.6 5.0 4.5 4.2 WeeKs needed to lose Weight at various CaloriC defiCits Table 12–4 *Calorie deficit = calories expended minus calories consumed. Each 3500-calorie deficit produces loss of 1 pound of fat. Most moderately active people need about 15 calories per pound to maintain their weight. © 2011, Stephen Barrett, M.D. Daily Calorie Deficit*Pounds to Lose W ee ks N ee de d > Part Three Nutrition and Fitness238 eating disorders Preoccupation with body image and dieting has stimu- lated many people to resort to extreme measures of weight control.24 Anorexia nervosa is a life-threatening condition in which food intake is severely limited. The afflicted individuals, most of whom are young women, have an intense fear of gaining weight or becoming fat, even though they are underweight. Bulimia (also called bulimia nervosa) is a disorder characterized by bingeing (episodes of eating large amounts of food) and purging (getting rid of the food by vomiting or using laxatives). In contrast with anorectics, most bulimics (a) do not get emaciated, (b) are aware that they have a problem, and (c) feel compelled to conceal it. About half of anorectics develop symptoms of bulimia, and about half of bulim- ics have a history of anorexia or eventually develop it.24 Inadequate food intake or extreme purging can cause metabolic imbalances that result in fatigue, irregular heartbeat, thinning of the bones, and cessation of men- struation. Frequent self-induced vomiting can damage the stomach and esophagus, make the gums recede, and erode tooth enamel. Approximately 0.5% to 1% of females between the ages of 15 and 30 become anorexic and 1% to 3% of adolescent and college-age women have bulimia.25 Eating disorders may require psychologic and di- etary counseling, as well as medical treatment for any physical ailments that have developed. If a patient’s weight becomes dangerously low, hospitalization with intensive therapy is recommended. Medical treatment for anorexia may require tube feedings or hyperalimentation (complete nutrition through the veins) if the patient will not or cannot eat. Dietary counseling may help an ano- rectic individual understand the importance of nutrition and instill healthy eating behaviors. Psychologic therapy should aim for greater self-understanding, clarification of family dynamics, and the development of the patient’s People who have met me within the last 25 years find it hard to believe that I was once a third bigger than I am now. Like many women in their early 20s, I had become obsessed with weight and quite miserable about the extra pounds that had begun to clutter up my five-foot frame. So, like millions of others in the same boat, I tried diet- ing. All kinds of diets. Many commercial programs and gimmicks and a few I made up on my own. And sure, I would lose weight, but then I’d gain it back—and usually some extra pounds to boot—when I got sick and tired of feeling deprived and living on eggs and grape fruit or cottage cheese and carrots or whatever happened to be the popular weight-loss concoction of the day. Believe me, I tried them all—even the ridiculous drinking man’s diet—and all they did was result in an ever-bigger me. Then one day I panicked. I was fat. But even more important, I realized, I was probably killing myself with my atrocious eating habits. I vowed to turn over a new leaf. I decided that if I was going to be fat, so be it, but at least I could be healthy and fat. I gave up diets and gimmicks and cycles of starv- ing and bingeing, and I started eating: three wholesome meals, with wholesome snacks if I was hungry between meals, and one little “no-no” each day—two cookies, a couple of spoons of ice cream, a thin sliver of cake or pie—something I loved and did not want to miss. No deprivation, no star vation, no bingeing. Only moderation. And I put myself on a regular exercise program. Every day I would do something physically chal lenging: walk- ing, cycling, skating, swimming, tennis—something that got me breathing hard (I kept thinking about how all that oxygen was restoring my cells to health) and feeling good about my body. Losing weight wasn’t part of this plan, but lose weight I did. Even though I was eating whenever I was hungry and consuming what felt like mountains of food, I lost weight: about seven pounds the first month and then about one or two pounds a month thereafter, until my weight stabilized two years later at 35 pounds lighter. And there it has stayed, give or take five pounds here or there, for a quarter-century. Trying to lose weight fast is probably the single big- gest mistake dieters make. Weight that comes off quickly nearly always comes back on even faster. You didn’t gain those extra pounds in a fortnight, and you shouldn’t be trying to take them off in two weeks, or even necessar- ily in two months or two years. The idea is to adopt an eating and exercise plan that you can go on and can stay on for the rest of your life, a program that will allow you to lose weight slowly, tone up your body gradually and eventually stabilize at a weight and shape that is right for you. Jane Brody23 Personal Health Columnist The New York Times A Plug for Fitness Personal Glimpse Chapter Twelve Weight Control 239 Weight-Control MYths vs faCts Table 12–5 Myth: You can’t get fat on a low‑fat diet. Fact: Restricting fat intake is useful in weight control and has distinct health advantages in terms of coronary heart disease and cancer. However, while it is more difficult to gain weight on a low-fat diet than a high-fat diet, it is by no means impossible. The net calories available to your body still count, whether they come from fat or carbohydrates. No matter what the source, if you eat more calories than you burn, the excess is stored as fat. People gain weight every day from too many calories from low-fat ice cream, cakes, cookies, mayonnaise, and margarine. Myth: Obesity results from psychologic problems. Fact: For many years, some people suffering from obe- sity underwent treatment for emotional distress under the assumption they were anxious or depressed and ate to compensate for some inner need. This simply is not true. For example, epidemiologic surveys have shown that neither manic/depressive illness nor schizophrenia is more common among obese than among lean people. Myth: People who binge‑eat do so because they have a deep sugar/carbohydrate craving. Fact: Laboratory studies have revealed that the food preferences of people with binge eating disorder, or a related “binge-purge” disorder known as bulimia, aren’t very different from those of the normal population. The problem is they can’t control the amount they eat. More recent studies suggest they may have a physiologic disturbance that begins at some point after the onset of the disorder and affects their sense of satiety. In other words, they may not experience the sense of fullness that normally occurs at the end of a meal until they have consumed an excessive amount of food. Myth: Obese people can “eat like a bird” and still not lose weight. Fact: Researchers at St. Luke’s-Roosevelt Hospital Center have found that obese men and women tend to under report the number of calories they actually con- sume. The fact is that, all things being equal, if they did eat very little, they would lose weight. Myth: Since genetics and obesity can be linked, trying to control obesity by diet won’t work. Fact: Despite your family history, the number of calories you consume still plays an important role in determining whether you will lose or gain weight. Myth: Through diet and exercise, you will be able to change the way your body fat is distributed. Fact: The location of body fat may be a direct result of whether you are male or female, your genetic makeup, your age, and whether you are under stress, smoke or drink. Diet and exercise may slim you—and improve your health—but won’t change fat distribution. Myth: Once obese people bring their weight down to a desirable level, that level can be easily maintained by eating the usual, moderate amount of calories. Fact: The body tends to resist intervention that lowers or raises its fat content. Scientists have found that re- ducing weight causes some metabolic processes to slow down so that it takes fewer calories than before to make you gain weight again. In other words, to maintain the same healthy weight, an obese person who has reduced often must eat fewer calories than someone who’s never been obese. It’s one reason for the high recidivism rate among dieters. The reverse is also true. Gaining weight increases energy expenditure, which means that if you’ve been thin, it will take more calories than ever to keep your weight up. Myth: Obesity is due to a simple lack of willpower. Fact: The bulk of research evidence shows that there is a strong genetic component to obesity, which may re- flect a special vulnerability to an environment in which calorie-rich foods are relentlessly promoted. Several genes have been identified that not only influence appe- tite and satiety, but may also affect how efficiently the body stores food calories. Myth: Eating slowly will make you feel full faster, thus helping to reduce food intake during mealtime. Fact: There is no concrete evidence to support this claim. Recent laboratory studies in which eating rates were manipulated and food intake was measured showed no effect on the amount of food eaten. Myth: Certain fats, such as fish oils and olive oil, are not fattening. Fact: Studies show that, like saturated fats, monoun- saturated fats (such as olive oil, which is associated with the popular Mediterranean diet) and polyunsatu- rated fats (such as fish and vegetable oils) are fattening. Although there is a difference in the way various fatty acids are metabolized in the body, all fats can promote obesity and should be eaten in moderation. Research findings have revised many long-held beliefs and assumptions about obesity. These examples were as- sembled by the Nutrition Research Center at St. Luke’s-Roosevelt Hospital Center and the Nestlé Research and Development Center, Inc. Part Three Nutrition and Fitness240 own individual personality. Additional information about eating disorders can be obtained from the National As- sociation of Anorexia Nervosa and Associated Disorders. Eating disorders are common among participants in some of the performing arts and among athletes in sports that emphasize leanness or have weight classifications. The activities include ballet, dance, gymnastics, wres- tling, judo, boxing, weightlifting, bodybuilding, figure skating, diving, horse racing, and distance running. The desperate methods used to keep thin or to “make weight” for a competition include rubber suits, excessive heat in saunas, diuretics, laxatives, self-induced vomiting, excessive exercise, starvation, and dehydration—all of which have potentially dangerous consequences. the u.s. Weight-loss MarKetplaCe A major survey conducted in 2003 found that 65% of women and 42% of men were trying to lose weight.26 Marketdata Enterprises,3 an independent market research and consulting firm, estimated that 2010 sales of weight- loss products and services totaled $60.9 billion. The leading categories were diet soft drinks ($21.2 billion); health clubs ($19.5 billion); bariatric surgery ($5.8 bil- lion); artificial sweeteners ($2.5 billion); over-the coun- ter (OTC) appetite suppressants and meal-replacement products ($2.7 billion); low-calorie prepared foods ($2.3 billion); medically supervised diet programs ($2.5 bil- lion); commercial weight-loss center programs ($3.3 billion); and diet books, cassette tapes, and exercise videos ($1.2 billion). QuestionaBle diets Most fad diets, if followed closely, will result in weight loss—as a result of caloric restriction—but they are mo- notonous and often dangerous to health if followed for long periods. Yet many obese individuals are sufficiently desperate or gullible to try one questionable method after another. A highly publicized diet will attract many people who try it for a short period, lose weight, and encourage others to do the same. Because most will regain their lost weight, the market for “new” diets is inexhaustible. Dr. Philip L. White, former director of the AMA Department of Foods and Nutrition, warned against try- ing any method promised to induce weight loss of more than 2 pounds a week. He gave these additional tips for spotting an unreliable diet promotion27: • It suggests that a nutrient or food group is either the key to weight reduction or the primary “villain” that keeps people overweight.

• It claims to be a revolutionary new idea.
• It reports testimonials rather than documented research. • It refers to the author’s own case histories, but does not

describe them in detail. • It claims 100% success. • The promoter claims persecution by the medical profession. When questionable diets are promoted with refer- ence to research studies, the research is typically unpub- lished, poorly designed, published in obscure outlets, and/or based upon studies on animals rather than people. The National Council Against Health Fraud28 warned consumers to be wary of any weight-control program that encourages the use of special products rather than learning how to make wise food choices from the con- ventional food supply. Most fad diets lack important nutrients or even whole food groups and are therefore nutritionally unbalanced. The three main types of unbalanced approaches to weight loss are complete fasting (starvation), supplemented fasting, and low-carbohydrate (high-protein) diets. Complete Fasting The most drastic way to reduce caloric intake is to stop eating. Intake of water, of course, is still necessary. Fast- ing has been used for weight reduction since ancient times. Losses will be greatest in the heaviest people and least in individuals who are the lightest. A few days of fasting are unlikely to be dangerous, but prolonged fast- ing leads to dangerous metabolic imbalances. Glucose is essential for the brain and is the preferred fuel for other body tissues. Glucose is obtained easily from carbohydrates, less easily from proteins, but not at all from fats. After a few days of total fasting, body fats and proteins are metabolized to produce energy. The fats are broken down into fatty acids, which can be used as fuel. If sufficient carbohydrate is not available, the fatty acids may be incompletely metabolized and yield ketone bodies, causing a condition called ketosis. This situation, if prolonged, is hazardous because proteins must be broken down to ensure an adequate supply of glucose for the brain. During fasting, because no proteins are available from food, they are obtained from muscles and major organs such as the heart and kidneys. A pro- longed fast can also lead to anemia, liver impairment, kidney stones, postural hypotension (low blood pres- sure), mineral imbalances, and other adverse effects. Part of the reason for fasting’s popularity is that it produces dramatic weight loss during its early stages. As ketosis begins, large amounts of water will be shed, leading the dieter to think that significant weight reduc- tion is taking place. However, most of the loss is water rather than fat; the lost water is regained quickly when eating is resumed. Appetite, often reduced during ketosis, Chapter Twelve Weight Control 241 also returns when a balanced diet is resumed. Claims that fasting “cleanses the body of toxic chemicals” are false. Supplemented Fasting Medical researchers have discovered that if fasting in- dividuals eat small amounts of protein, the protein will break down slowly to provide the glucose needed by the brain. Eating carbohydrates for this purpose does not work because it triggers an insulin response that causes intense hunger. In the early 1970s Dr. George Blackburn and colleagues at the Deaconess Hospital in Boston developed the “protein-sparing modified fast” in which fasting patients were given small amounts of high-quality protein along with noncaloric liquids, vitamins, calcium, potassium, other minerals, and some- times glucose. Patients were initially hospitalized for 1 week of evaluation and then followed-up closely as outpatients. Their diets were carefully calculated. The program emphasized not only diet but also an overall approach that included exercise, instruction in nutrition, and behavior modification. Today, modified fasting can be done safely on an outpatient basis under skilled medical supervision. However, experts have expressed fears that the vigorous marketing of meal-replacement drinks will encourage people to use these products inappropriately. The more meals replaced and the lower the number of calories consumed daily, the greater the risk. The risk is greatest in individuals who are not severely overweight. The FDA requires a warning label on weight-reduction products if more than half of their calories come from protein. Very-low-calorie (VLC) diets contain fewer than 800 calories per day, most of them from high-quality proteins, plus vitamins and minerals, particularly potassium. Some programs use liquid formulas, whereas others utilize food sources (poultry, fish, and lean meats). In 1993, the National Task Force on the Prevention and Treatment of Obesity29 recommended against their use because (a) clinical trials had shown that low-calorie diets are just as effective, and (b) VLC dieters are at increased risk for developing gallstones. Low-Carbohydrate Diets Most low-carbohydrate diets do not explicitly limit the intake of proteins, fats, or total calories. Some promot- ers claim that unbalancing the diet will lead to increased metabolism of unwanted fat even if the calories are not restricted. This is not true, but calorie reduction is likely to occur because the diet’s monotony tends to discourage overeating. A diet that is very low in both carbohydrates and calories will produce ketosis and rapid initial weight loss, as noted in the Complete Fasting section. Some promoters of low-carbohydrate diets regard carbohydrates as “the dieter’s number one enemy.” This designation is inappropriate because calories from any source contribute equally to weight gain if consumed in excess. Some diets that restrict carbohydrates permit enough to be eaten that they do not produce ketosis. The most popular of these is the South Beach Diet,30 which was published as a book in 2003. This diet is based on the premise that eating the wrong carbohydrates causes blood sugar to soar, which triggers an insulin response that drops the blood sugar and causes carbohydrate cravings that result in overeating. The Tufts University Health & Nutrition Letter31 says that any such reaction is a minor factor in weight control and that, “like many popular diet books, this one is replete with faulty science, glaring nutrition inaccuracies, contradictions, and claims of scientific evidence minus the actual evidence.” The least restrictive of the popular low-carbohydrate diet books is The Zone32 which advocates eating 40% carbohydrate, 30% protein, and 30% fat at every meal. The book defines the “zone” as a metabolic state in which the body operates at optimal efficiency. It further claims that maintaining a 4:3 ratio between carbohydrates and proteins triggers hormonal changes that burn off excess body fat and produce health-promoting eicosanoids. Cheuvront33 has dissected the book’s theories and con- cluded that they lack scientific support. Researchers who compile the National Weight Con- trol Registry analyzed the diets of 2681 members who had maintained at least a 30-pound weight loss for 1 year or more. They found that fewer than 1% had followed a diet similar to the Atkins program. Most followed high- carbohydrate, low-fat diets.34 The most publicized low-carbohydrate diet is the one advocated by the late Robert C. Atkins, M.D., of New York City, whose books sold millions of copies. Atkins advocated his diet for more than 30 years and stated that more than 60,000 patients treated at his center had used his diet as their primary protocol. However, he never published any study that documented what happened to his patients. The current Atkins plan35 has four steps: a 2-week “induction” period, during which the goal is to reduce carbohydrate intake to under 20 g per day, followed by three periods during which carbo- hydrate intake is progressively raised but kept below what Atkins called “your critical carbohydrate level” for losing or maintaining weight. The dieter was permit- ted to eat unlimited amounts of noncarbohydrate foods “when hungry,” but ketosis tends to suppress appetite. In 2000, researchers who analyzed sample menus from Atkins’s books reported that the diet contained 59% fat Part Three Nutrition and Fitness242 and provided fewer servings of grains, vegetables, and fruits than recommended by the U.S. Dietary Guidelines. The investigators warned that although the diet can pro- duce short-term weight loss, long-term use was likely to increase the risk of both cardiovascular disease and cancer.36 Recent studies have found that low-carbohydrate diets can produce modest weight loss and reduction in cardiac risk factors, which means that they are safer than previously thought. The most comprehensive such study was reported in 2009 by Sacks and others,37 who fol- lowed 811 overweight adults for 2 years. Each participant was assigned to one of four reduced-calorie diets with the following targeted percentages of calories derived from fat, protein, and carbohydrates: 20/15/65, 20/25/55, 40/15/45, or 40/25/35. Among the 80% of participants who completed the trial, the average weight loss was about 9 pounds, and 14% to 15% of the participants lost at least 10% of their initial body weight. Satiety, hunger, satisfaction with the diet, blood lipid levels, and attendance at instructional sessions were similar for all four groups, but those who attended the most in- structional sessions tended to have the best results. The researchers concluded: “Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize.” However, it has not been determined whether using a low-carbohydrate diet for many years is safe or can reduce the incidence of coronary heart disease. Low-carbohydrate diets are unsuitable for people with coronary artery disease, gout, or kidney disease. In addition to being checked for these conditions, low- carbohydrate dieters should have their blood cholesterol levels monitored and should stop the diet if their 3-month total or LDL-cholesterol levels rise sharply. Among those whose cholesterol levels improve, the improve- ment is thought to be related to weight reduction, but no published study has examined the effect of the diet on the coronary arteries. Because increasing the amount of carbohydrates in a diet can raise triglyceride levels and reduce HDL, a low-carbohydrate diet may be appropriate for obese individuals with abnormally high triglyceride levels.38 Future genetic research may be able to determine which diets are best for which people. The popularity

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