Informative Articles

Weight-loss drug has dual benefits for type 2s.(In the Pipeline) Diabetes Forecast v51, n11 (Nov 1998): 35 (3 pages).COPYRIGHT 1998 American Diabetes Association Inc.

Mulrow, Cynthia D.Helping an obese patient make informed choices. (Clinical Review) British Medical Journal v317, n7153 (July 25, 1998): 266 (2 pages).Copyright 1998 British Medical Association (U.K.

Work Janis A.. Exercise for the overweight patient.Physician and Sportsmedicine v18, n7 (July, 1990): 113 (2 pages).

Weight-loss News That's Easy to Stomach.University Diet & Nutrition Letter v14, n2 (April, 1996):1 (1 pages).COPYRIGHT Tufts University Diet and Nutrition Letter 1996

Bovsun, Mara The Diet Dilemma. (includes related articles) (Cover Story) Medical World News v33, n5 (May, 1992):17 (6 pages).COPYRIGHT Medical Tribune Inc. 1992



Weight-loss drug has dual benefits for type 2s. (In the Pipeline) Diabetes Forecast v51, n11 (Nov 1998): 35 (3 pages).COPYRIGHT 1998 American Diabetes Association Inc.

Orlistat (Xenical), a weight-loss drug pending approval by the Food and Drug Administration, has been shown to have not one but two major benefits for obese people with type 2 diabetes In a 57-week multi-center study of obese patients with type 2, researchers observed greater weight loss and better glycemic control in patients who took orlistat compared with those who took a placebo (a pill containing no active ingredients).

Of the 254 patients who completed the study, 138 took orlistat and 116 took a placebo. All 254 followed a diet slightly reduced in calories to help them lose weight, and all were controlling their diabetes well with sulfonylurea drugs when the study began.

The difference in weight loss between the two groups became apparent only four weeks into the study. Those who took orlistat lost weight at a faster rate than those who took the placebo. At the end of the study, the orlistat group had lost an average of 13 pounds, compared with an average of 9.5 pounds in the placebo group. The orlistat group also attained lower levels of fasting glucose than the placebo group. As a result, the average dose of sulfonylurea medication decreased more in the orlistat group than in the placebo group. In the orlistat group, 43 percent of the participants decreased the amount of oral sulfonylureas they took, and 12 percent were able to discontinue oral sulfonylureas entirely. In the placebo group, only 29 percent were able to decrease their oral sulfonylurea dose. The researchers believe that the better glycemic control in the orlistat group stems from that group's greater weight loss; weight loss has been shown to improve glycemic control. The orlistat group also had improved serum lipids, with better levels of total cholesterol, lower levels of low-density lipoprotein (LDL, or "bad") cholesterol, and lower levels of triglycerides.

Orlistat belongs to a new class of drugs called lipase inhibitors.Instead of reducing appetite as many diet drugs do, orlistat and the other drugs in its class reduce the amount of dietary fat absorbed in the intestines. If the fat is not absorbed, it will not get into the bloodstream to affect lipid and cholesterol levels. Orlistat is not without side effects, however. The unabsorbed fat passes through the intestines, which can result in gastrointestinal effects ranging from oily stools to fecal incontinence. Moreover, because the fat is not absorbed, fat-soluble vitamins like vitamin E and beta-carotene are not broken down and made readily available for use in the body. The orlistat group did experience a decrease in vitamin E and betacarotene absorption during the study, but the decrease was offset by vitamin supplements.




Mulrow, Cynthia D.Helping an obese patient make informed choices . (Clinical Review) British Medical Journal v317, n7153 (July 25, 1998): 266 (2 pages).Copyright 1998 British Medical Association (U.K.)

Not long ago, a patient, whom I will call Mrs. Bariatrico, asked me to prescribe a diet pill for her. Mrs. Bariatrico is a middle class woman aged 48 years. She is 1.6m tall and weighs 77.2 kg. Her body mass index is 30.2 and her waist to hip ratio is 1.0 Mrs. Bariatrico is healthy and does not smoke. She told me she plans to enroll in a commercial diet programme and believes her ability to change her lifestyle is good? Her main concern is cosmetic--she values "looking good" and considers weight loss an important outcome.

As her primary care provider, I had several concerns. I knew the health insurance system that serves Mrs. Bariatrico has no formal weight loss programmes, and the cost of appetite suppressing drugs in not reimbursed. I had some doubts about my own ability to manage obesity and asked the following questions:

What are the actual health risks associated with obesity in a middle aged woman with few cardiovascular risk factors?

What are the expected benefits and hazards of weight loss?

What are Mrs.Bariatrico's treatment options and their expected benefits and adverse effects?

Risks of obesity

Obesity is a chronic condition associated with hyperlipidaemia, hypertension, non-insulin dependent diabetes, gallbladder disease, some cancers, sleep apnea, and degenerative joint disease. [23] Assessing the magnitude of risk for these conditions is complicated by several elements: many patients have several interacting risks; measuring the impact of some risks requires large, long cohort studies; and there are several confounding factors such as smoking and the duration of obesity.Regardless of these cautions, studies suggest that people who are more than 20% overweight have prevalences of hyperlipidaemia, hypertension, and diabetes that are between 1.5 and 3.5 times higher than those in people whose weight is normal.[23] The morbidity risks increase steadily from a body mass index of 25-30 and more rapidly at higher index values.Mortality risks increase above body mass indices of 20-27.45. Relevant to Mrs. Bariatrico, values of 29.0-31.9 in non-smoking middle aged women are associated with a relative mortality risk of 1.7 (95% confidence interval. 1.4 to 2.2; reference body mass index [is less than] 19). [4]

Expected benefits and hazards

Randomised trials confirm several physiological benefits--including reductions in blood pressure and glucose and lipid concentrations--when weight is reduced by 10-15%. [2] Trials are neither large enough nor long enough to identify survival benefits.One observational study that lasted 12 years showed that an intentional weight loss of 0.5-9.0 kg in overweight women with disorders related to obesity was associated with a 20% reduction in all cause mortality (relative risk = 0.80; 0.68 to 0.94). [6] Potential hazards of weight loss include increased risks of gallstones during rapid weight loss and loss of bone density.[2]

Treatment options

A comprehensive systematic review from the Centre for Reviews and Dissemination evaluates treatment options appropriate for Mrs. Bariatrico.[7] These include diet, exercise, and appetite suppressing drugs.A recent book describes many complementary therapies, including herbal remedies and chromium, but none have been adequately evaluated in controlled trials?

Diet and exercise

Randomised controlled trials show that diets allowing an intake of 1200 kcal/day coupled with behavior modification result in an approximate weight loss of 8.5 kg at 20 weeks.[9] Providing patients with food and meal plans, focusing on restricting fat as well as calories, and encouraging daily self monitoring of weight may be particularly effective strategies.[7] Very low calorie diets of less than 800 kcal/day result in a weight loss of approximately 20 kg at 12 to 16 weeks. One half to two thirds of the weight loss is maintained at one year. [9] Adding regular aerobic exercise results in minimal additional weight loss (approximately 2.5 kg after six months) and limits the amount of weight regained.[10] Resistance exercise has little effect on weight but increases the lean body mass.[10]

Appetite suppressants

Double blind randomised trials of longer than six months' duration show that antidepressant serotenergic agents such as fluoxetine are not effective weight loss treatments.[7.11] Other serotonergic agents, dexfenfluramine and fenfluramine (a racemic mixture of D-fenfluramine and L-fenfluramine), are effective when combined with diet. [7.11] Five trials, in which 1029 patients participated, showed that the weight loss with dexfenfluramine was 2.5 to 8.7 kg greater than with placebo at six months; two trials showed losses of 2.6 and 4.2 kg at 12 months.[11] The combination of fenfluramine and phentermine (colloquially known as fen-phen) resulted in a loss of 9.7 kg after six months compared with placebo. The two drug are sibutramine (serotonin and noradrenergic reuptake inhibitor) and orlistat (a fat absorption inhibitor). In one multicentre randomised trial, sibutramine showed a 2.8 kg loss compared with placebo at 12 months.[7] In a preliminary report from one centre of a multicentre trial comparing orlistat with placebo, weight reduction with orlistat was 3.1 kg more than with placebo at six months.[12] Trial data beyond 12 months of active treatment are not available for either of the two agents, and effects on mortality are not known.

Adverse effects that occur in more than 10% of patients taking dexfenfluramine include tiredness, diarrhea, and dry mouth. Use of appetite suppressants (mostly dexfenfluramine) for more than three months is associated with pulmonary hypertension.[13] The risk is estimated at 23-46 cases per million per year or one in 22,000-44,000 patients taking appetite suppressing drugs. Highly publicized case series describe unusual heart valve deterioration in 60 otherwise healthy women taking newer agents.[1415] Most were taking the combination of fenfluramine and phentermine, but six were taking either fenfluramine or dexfenfluramine alone. [14 15] In addition, a case series of 291 asymptomatic people taking these drugs showed that 92 had evidence of valvular disease, primarily aortic regurgitation.[16] This information prompted manufacturers to withdraw dexfenfluramine and fenfluramine from the market in September 1997.

The informed decision

I gave Mrs. Bariatrico feedback on the health risks of obesity, listed the treatment options, and advised her about the expected effects. She viewed the health risks of obesity as relatively minor and reiterated her primary value of losing weight so she would "look and feel good." She was surprised that the weight loss expected from diet pills was not greater and worried about possible serious adverse heart effects. She was determined to try a low fat, low calorie diet and daily exercise. I praised her willing ness to tackle difficult lifestyle changes. On her way out the door, she turned, smiled at me, and requested a prescription for phentermine--one of the few remaining appetite suppressants available on the market.

Weight-loss news that's easy to stomach. University Diet & Nutrition Letter v14, n2 (April, 1996):1 (1 pages).COPYRIGHT Tufts University Diet and Nutrition Letter 1996

Ever hear talk about how the stomach shrinks after a person has been dieting, resulting in less hunger than previously? Well, the stomach - a grapefruit-sized organ when empty - can't really get any smaller. But new research shows it does lose its capacity to stretch as much as it did when it was accustomed to holding more food. And that makes a dieter feel full on less.

Investigators at Columbia University's Obesity Research Center proved the point when they measured the holding capacity of 14 obese people's stomachs both before and after putting them on a weight-loss regimen. To make the measurements, the researchers threaded balloons into the subjects' stomachs through their mouths and throats and gradually filled them with water. After each two-fifths of a cup, the men and women rated their feelings of fullness, nausea, and abdominal bloating on a scale of 1 to 10, with 10 being the worst. When a participant rated discomfort at 10, the balloon filling stopped.

Before beginning the diet, the men and women, who weighed on the order of 220 pounds, could hold an average of almost four cups of water in their stomachs.Four weeks later, when they had lost anywhere from 12 to 28 pounds, their average holding capacity before they reached 10 on the discomfort scale was less than three cups - a decline in stomach capacity of 27 percent.

A second test in the same subjects relied not on their subjective responses but instead used a machine to measure the pressure exerted on the stomach wall with increasing amounts of water. In this test, stomach capacity went down by 36 percent In fact, after four weeks of dieting, the women could no longer hold any more volume in their stomachs than a group of normal-weight women observed in a separate study.

The researchers hypothesize that it is not obesity per se that increases stomach capacity but overeating. Specifically, the problem appears to be eating large individual meals rather than eating too many calories over the course of the day. Consider that normal-weight bulimics, who sometimes eat thousands of calories at a time during binges, have even greater stomach capacity than obese people of the same age.

A larger stomach capacity not only makes it easier to eat larger meals; it also apparently increases the desire for them. The researchers point out that the stomach has special "stretching sensors" responsible for sending signals to the brain to induce satiety. But they believe the sensors may not get the signals going until the stomach has been distended to a certain proportion of its capacity. Therefore, the more the stomach can hold, the larger the meal needed to inform the brain that a person is full.

Fortunately, the converse appears to be true as well. The less food the stomach becomes used to holding comfortably, the less it takes to inform the brain that the body has had enough to eat. That's good news for dieters.

Spring, a member of the Sacramento, Calif.-based National Association to Advance Fat Acceptance, is part of a growing rebellion against calorie counting, starvation diets and the $33-billion-a-year diet industry. For people like her, the question is no longer "which diet" but whether to diet at all.

"Diets don't work and permanent weight loss is elusive," said Sally Smith, executive director of the 3,500-member group, herself a 300-pound woman, who also started dieting when she was seven. "Fat people are here to stay."

A small group of physicians and therapists have joined the diet backlash, according to Joseph McVoy, Ph.D., director of the 120-member Association for Health Enrichment of Large Persons.

"We are at a crossroads," Dr. McVoy said. "It is time we have to change our underlying assumptions about the world.

" Dr. McVoy, who runs an eating disorders clinic at St. Albans Psychiatric Hospital in Radford, Va., said that for 30 years there has been research showing that dieting is not effective for long-term weight control. "There is no diet that can show you a success rate of five years," he said. "Why do we continue to torture these people when we know it doesn't work?"

Practicing physicians are beginning to question whether everyone can, or should, reduce. "It's a kind of madness to say that everybody should lose weight," said Dr. Alvin J. Ciccone, a Norfolk, Va., family physician who admits that he is an "overweight doctor," and does not practice what he preaches. He said he lost about 100 pounds, only to gain back half of the weight.

"The problem with America is that everybody feels that to be thin is to be healthy," he said. "I wonder if this is not a gimmick of America."

The anti-diet revolution alarms Dr. Theodore VanItallie, a leader in obesity research since 1952. "It is a disheartening spectacle to observe so many victims of our obesity-promoting environment collaborating actively in their own downfall," he said. "They shouldn't participate."

Dr. VanItallie says there is overshelming evidence that fat people have an increased risk of diabetes, coronary heart disease, hypertension, gout, gallbladder disease, and endometrial and breast cancer. Fat women, for example, run six times the risk of developing gallstones as their slim counterparts.

"The doctor has the responsibility to inform patients of these risks," he said. "To say that no one should diet is ridiculous."

The health paradox

At a National Institutes of Health (NIH) consensus development conference held in early April, a panel of obesity experts observed a "health paradox" in modern America--many people who do not need to diet are trying to do so, while others who may need to lose weight for health reasons are not succeeding.About one-third of American women and a quarter of American men are trying to lose weight at any given time, according to the NIH, and they spent about six months of the last year on the various weight-loss regimens. The panel also concluded in its consensus statement that those who take part in weight-loss programs quickly regain whatever they lose. The long-term failure rate is estimated at 95%.

"We're in an epidemic of dieting inappropriately," according to internis/endocrinologist Dr. C. Wayne Callaway, of Washington, D.C., and a member of the Dietary Guidelines Advisory Committee of the U.S. Department of Agriculture. Dr. Callaway estimates that only one in 10 women who diets does so for health reasons. "The guys with the beer bellies are not trying to lose weight," he said. "Ironically, those are the people who most need to drop pounds, because abdominal fat poses the greatest health risk."

Despite the dieting craze, Americans are getting fatter. The latest data from the National Center for Health Statistics' health and nutrition survey show that 25% of the adult population, or 34 million Americans, are 20% or more over ideal body weight.That number is within one percentage point of the figure given for the previous two studies, covering five-year spans. NIH statistics put the figure for overweight Americans closer to 34%, said Dr. Jay H. Hoofnagle, director of the division of digestive diseases and nutrition for the NIH.

Fast and abundant food and hectic but sedentary lifestyles helped to put on the weight, and spawned the diet industry. The Calorie Control Council, a diet-food trade group in Atlanta, Ga., said that about 48 million Americans are on diets, and 101 million are eating light, surgar-free or low-calorie fare, according to a 1991 survey.The number of dieters is down from the 1986 figure of 65 million. But at that time, there were only 78 million consumers of pared-down foods.

In 1989, about 1,000 new light products were introduced. Estimates for the total industry--diet books, fitness spas, commercial and hospital-based reducing plans, foods, pills and supplements--were in the range of $33 billion in 1991, according to Marketdata Enterprises, Inc., a consulting firm in Valley Stream, N.Y.

If the diets are doing little to slim down the American population overall, they have been wreaking havoc with those people caught on the diet merry-go-round, commonly known as yoyo dieting. The psychological impact of losing and regaining over and over can be devastating.

"I felt like a total failure. I had no sense of self-worth," said Aleta Walker, 35, who carries about 300 pounds on her 5 foot 6 inch frame. She started her life-long diet, which she said cost "tens of thousands of dollars," at age 12, when her doctor prescribed amphetamines and a 500-calorie meal plan. She quit just five years ago, after her second attempt at a liquid diet gave her gout. "All the diets have contributed to my being the size I am today," she said. "I was hungry all the time, constantly hungry and deprived."

That deprivation leads to depression and binge eating, said San Diego therapist Susan Ward, who runs a group she calls Beyond Feast or Famine. Her patients are encouraged to throw away the diet books and eat when they are hungry. But her major goal is getting her patients to abandon the self-loathing that accompanies repeated failed diets. Do they lose weight during her 12-week program? Ward admitted that some do, but most don't. When Ward takes people off diets, they "run rampant," she said. "Maintaining weight, not gaining, is a big goal." She focuses on getting her patients to start an exercise program, and make healthier food choices.

Dr. Callaway said that the idea that people can control their body fat is simplistic, and "based on the notion that all fat people are gluttons." This idea totally ignores heredity, he added. "Physicians think it is a matter of control, when 50% of the variation in weight is genetic," he said, citing studies on adopted twins that showed that no matter where a child was raised, weight patterns reflected those of the biological parents. "We start out with a pre-set tendency to be a specific height and weight," he explained.

Research is also indicating that genetically heavy people are sabotaged by their own bodies each time they try to lose weight.

"Our many years of research into the biological effects of weight reduction have shown that weight reduction is accompanied by metabolic changes that return the patient to the antecedent weight," said Dr. Rudolph L. Leibel, an associate professor at Rockefeller University in New York City, who has been studying obesity for 12 years. Long-terms efficacy is very difficult to achieve because calorie restriction provokes compensatory alterations in the body's use of energy.

Human bodies were designed to survive famines, and that mechanism undermines low-calorie diets. "If you cut back on your food, your body will adapt to starvation by burning less and less," Dr. Callaway said. In a normal person, food decreases appetite, he said, but it has the exact opposite effect in a person who has starved.

More harm than good?

A big surprise at the NIH meeting was a collection of epidemiologic studies contradicting the conventional wisdom that extra fat shortens lives. David F. Williamson, Ph.D., an epidemiologist in the division of nutrition at 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 loss and cardiovascular mortality, he said. "That is a twist that has puzzled folks." Dr. Williamson hypothesized that the cardiovascular complications may be a result of the loss of lean muscle tissue that is commonly seen with low-calorie diets.

Since epidemiology is an inexact science at best, Dr. Williamson said that the studies reported at the NIH need to be taken seriously, but require further study in a more controlled setting before they can be used to determine medical recommendations. "The anti-diet people are looking at this as another brick in the wall of their argument," he said.

Dr. F. Xavier Pi-Sunyer, co-director of the Center for Research in Clinical Nutrition at St. Luke's/Roosevelt Hospital Center in New York City, views the research on the dangers of weight cycling as "inconclusive." But he said that trying to set a predetermined weight goal for a fat person is not advisable.

Dr. Pi-Sunyer said that obesity-related health risks do not start until a patient is 20% or more above ideal body weight, or if there is an existing condition, such as hypertension. "There is reasonable data to suggest these people will benefit from losing," he said. "But they don't have to lose all their weight, reach a goal on the actuarial tables, to get a health benefit.

"If a person weighs 290 pounds, it makes no sense to choose a goal weight based on the average height-weight tables," Dr. Pi-Sunyer continued. "The initial weight loss might be 15 pounds, achieved slowly at a maximum rate of about two pounds per week. We do it in increments; we don't set the patient up for failure by moving too quickly."

Reducing programs should be based on an invididual's metabolism, not a pre-printed menu card, and a great emphasis should be placed on improving diet composition, reducing fats, for example, Dr. Callaway said. "The idea that everyone will lose weight on a 1,200-calorie diet is silly," he said.

Extreme measures, such as gastric reduction and 400-calorie liquid diets, should only be considered when there is a clear sign that a patient has an obesity-related disease, Dr. Pi-Sunyer said. "We consider gastric reduction only for people who have serious effects of obesity, such as heart disease," he said.

Ironically, by removing the patient's contact with a realistic eating environment, these techniques succeed in helping patients dro pounds, but fail in helping them keep the weigh off. "They don't have to think about it," said Dr. Pi-Sunyer, who added the same is true of ultra-low-calorie liquid diets. "When people are on a liquid diet, they don't deal with food, so they don't learn much," he said. "What one wants to do is get them to change lifestyles."

Both anti-diet and traditional weight-loss advocates agree that some form of exercise is crucial in maintaining weight loss or establishing a healthier lifestyle, no matter what the scales say.

Whether patients weight 150 pounds or 600 pounds, they require "healthy physical activity" like walking, Dr. McVoy said. But shoving a formerly sedentary 500-pound person into "an aerobics class with mirrors, and a lot of lycra and spandex" is sure to fail. Slowly, painlessly introduce the activity, Dr. McVoy said, and the patient will continue and make it part of a daily routine. With one of his larger patients, he said he recommends five minutes on a treadmill. "Now that patient walks about a mile a day, and has slowly lost 100 pounds," Dr. McVoy said. "Water aerobics is another good choice because the water's buoyancy reduces joint stress."

Dr. VanItallie said that the activity level recommended for cardiovascular fitness--20 minutes a day, three times a week--is not adequate if you want to burn calories. "It does not have to be rigorous," he said, nothing that two hours of walking a day consumes nearly 500 calories.

Unless a person is willing to make exercise and eating less a lifetime commitment, Dr. VanItallie believes that it is a waste of time to start a weight-loss program. "The physician has to assess whether the patient has an understanding of the problem and the intellectual ability to change lifestyle and manner of eating," he said.

As in other chronic conditions, earlier intervention may keep the problem from getting out of hand. "Don't wait until a patient is 300 pounds," Dr. Pi-Sunyer advised. If weight starts to drift about 20% above normal, he said it is time to alter lifestyle with small increases in activity and decreases in caloric intake. Early interventions can be valuable for preventing obesity in women, who in general continue to gain weight throughout adulthood.

On the flip side, he said that his clinic turns away people who say that they want to lose 15 pounds just to fit a cultural image. "There, I tend to agree with the anti-diet people," he said. "The ideal image out there of women who are so thin is biologically incorrect." He estimated that fashion models may have body fat around 6%, where an average woman will carry around 20% to 25% of her weight in fat.

Dr. VanItallie summed up the problem by stating, "In prehistoric times, primitive man hunted for food; modern man is hunted by food. While we can't change society, patients have to learn to defend themselves against this."