IS OBESITY A KILLER DISEASE?
One of the reasons diet doctors like these are becoming popular again, and other physicians are treating obesity more often in their practices, is that obesity is being increasingly viewed as a killer disease. A hundred years ago, except in extreme cases, fatness was considered a simple physical trait, a natural variation in human size. Then, with all of the emphasis our culture put on discipline, restraint, and physical perfectibility, being fat became a moral problem. The more people tried to treat this problem — often unsuccessfully — the more it came under the auspices of the medical profession. Now obesity is widely described as a disease, and, as Americans get fatter, an epidemic.
Is obesity really a disease? Do people get sick and die because of the extra pounds they carry on their frames? Is it, as the Oxford English Dictionary defines disease, “a condition of the body… in which its functions are disturbed or deranged”? Are fat people always unhealthy?
Two prominent obesity researchers who recently formed the American Obesity Association (AOA), University of Wisconsin physician Richard Atkinson and University of California at Davis nutrition expert Judith Stern, say obesity is a disease, and many of their colleagues share their view. “Obesity is a disease that affects at least 70 million Americans: more than one-third of all adults and one in five children,” the researchers state in their AOA brochure. “Some people are more susceptible to obesity than others. Each year obesity causes at least 300,000 excess deaths in the US and costs the country more than $100 billion. Obesity is the second leading cause of unnecessary deaths.” The researchers describe obesity as responsible for increasing the risks of high blood pressure, diabetes, heart disease, stroke, gall bladder disease, and cancer of the breast, prostate and colon. These same statistics and lists show up frequently in the literature on obesity, as well as in books promoting diets, at FDA hearings on new diet drugs, in patient brochures in diet doctor’s clinics, in medical weight loss product sales packets sent to physicians, and in ads for commercial weight loss centers. The campaign report for “Shape Up America” the C. Everett Koop Foundation’s 1995 health crusade, for instance, uses these numbers, and calls obesity “one of the most pervasive health risks affecting Americans today.”
These “facts” about obesity, however, are not as straight-forward as they may seem. Most obesity researchers agree that like diseases, some people inherit a tendency to become fat (which is often encouraged by an environment where many people get little exercise and eat a high-fat diet). But beyond that, many researchers say obesity is not a disease, and does not, in itself, make people ill. There are, in fact, a number of questions about obesity and health that researchers are quite divided on: Does obesity lead to illness, and if so, how? How fat do you have to be to be at risk? Is being fat dangerous, or is it the sedentary lifestyle that often goes along with being fat? If you lose weight, will you be as healthy as a person who was never fat to begin with? There are no clear answers to these questions, and given the confusion, it pays to be skeptical when some obesity researchers call fatness a “disease” or fire off statistics about how many people it kills.
Take, for instance, the claim that a third of all adults are “affected by obesity.” That number initially comes from a national survey: The National Health and Nutrition Examination Survey (NHANS) tracked the weights of between 6000 and 13,000 adults from 1960 to 1991. “Overall,” said researchers who reported on the data in the Journal of the American Medical Association in 1994, “approximately one third of all adults in the United States were estimated to be overweight.” What do they mean by “overweight”? In the report, researchers defined “overweight” as having a Body Mass Index of greater than 27.8 for men, or 27.3 for women (BMI is weight in kilos divided by height in meters squared; you can calculate your BMI by multiplying your weight in pounds by 700, divide by your height in inches, then divide by your height again.) To translate that into real numbers, they’re calling a 5’ 5” woman overweight at about 165 pounds, and a 5’10” man at 195 pounds.
But does “overweight” mean the same as “obese”? For the most part, researchers say no. Most Americans who are overweight are only slightly so, with a BMI of 27 to 30. Some researchers call this “mildly obese,” and others say it’s just chubby. But whatever they call being about 20 to 40 pounds higher than ideal weight, there’s very little evidence that it’s bad for your health. In most studies, the health risks associated with being fat don’t shoot up until someone is severely obese, or about 75 to 100 pounds over an ideal weight. Severe obesity means a BMI of 35 or heavier; that’s 210 pounds at 5’5” tall, and 244 pounds at 5’10”. Only eight percent of the population has a BMI of 35 and over. So to say that third of the American population is obese and at some health risk for the condition is quite exaggerated.
It may be the idea that obesity is a “disease” that makes researchers and physicians use the words “overweight” and “obese” interchangeably. The logic is that if being obese means being diseased, then being a little overweight means being a little diseased. A 1994 Institute of Medicine report on weight loss treatment — written by a panel of obesity experts, many of whom are paid to sit on the scientific boards of weight loss companies — reflects this idea that overweight people are in the first stages of serious obesity. While the report explicitly says that being slightly overweight does not put people at any additional risk for disease, and that too many American women are preoccupied with their weight anyway, it nevertheless sounds a warning: “This is not to say, however, that slightly overweight individuals who wish to reduce to improve their appearance and enhance self-esteem should be dissuaded from doing so. Some of them may be at the first stages of disease, and treatment might prevent further problems.” But why treat slightly overweight people who have no other signs of illness? By dieting, they run the risk of putting themselves in the first stages of a “disease” called weight obsession, which can lead to real health problems, such as eating disorders, and an endless cycle of dieting, bingeing, weight preoccupation, and despair.
The next claim worth examining is that obesity causes 300,000 excess deaths per year in the United States. This claim is based on an estimate, done by researchers Anne Wolf and Graham Colditz at Harvard Medical School, using data from the Nurse’s Health Study (the same study from which Harvard researcher JoAnn Manson claimed that being ten or twenty pounds overweight led to an increased risk of early death). Based on the number of women who died from various diseases, and their body weight, the researchers extrapolated that obesity was the direct cause, nationwide, of 171,490 coronary heart disease deaths, 39,679 diabetes deaths, 53,087 cancer deaths, and 10,000 cerebrovascular deaths per year.
But the problem with this kind of analysis, say other researchers, is that you can’t make a direct cause-and-effect link between obesity and diseases. Just because people who are fat are more likely to die of cancer doesn’t mean that their fatness caused the cancer. Other lifestyle factors that tend go along with obesity, which the researchers in the Nurses Health Study did not take into account — such as a lack of exercise or a high-fat diet — may have contributed to the deaths, not the fatness itself. Studies on obese people who exercise, for instance — who live longer than lean people who don’t exercise — may prove that inactivity is the cause of many of the problems we associate with obesity, not obesity itself. Exercise physiologist Steven Blair, at the Cooper Institutes for Aerobics Research, has done studies that show that if you exercise, your weight — up to a BMI of 40 — doesn’t put you at any increased risk for early death at all. It may turn out that obesity is, for the most part, a red herring in the health debate.
“Nobody ever dies of obesity,” says David Levitsky, a nutrition and obesity expert at Cornell University. Obesity, he says, is often a marker for other health problems caused by a sedentary lifestyle, but is itself not necessarily dangerous. “If you’re a large person and you do not suffer from any other health problems, then there is no reason for you to lose weight.”
If a person does suffer from other health problems, however, then serious obesity may indeed aggravate the situation. Almost all of the studies that look at the health risks associated with obesity — researchers call them “comorbidities,” by which they mean high blood pressure, high cholesterol or blood sugars, diabetes, or other conditions that often go along with being fat — show that those risks do increase when people are very fat, meaning about 100 pounds or so overweight. In particular, researchers have shown that having abdominal obesity — an apple shape — can be dangerous. Belly fat is rather active in the body, unlike fat in the hips and thighs, which sits there and causes no harm. Fat cells in the abdomen release fatty acids directly into the liver, where they interfere with the liver’s job of breaking down insulin, thereby increasing the amount of insulin circulating in the body. This sets off a vicious cycle known as insulin resistance: With more insulin circulating, cells grow more resistant to what it does — metabolize fat — and so produce even more liver-damaging fatty acids. Eventually, this can cause problems including high blood sugars, high blood pressure, lower HDL (good) cholesterol, and heart attacks. Regardless of BMI, many researchers say that having a waist-to-hip ratio — waist measurement divided by hip measurement — of less than .80 for women or .95 for men is likely to be healthy. So men with beer bellies are much more likely to have health problems related to their weight than women with big hips and thighs.
The bottom line isn’t that obesity causes 300,000 deaths per year. It’s more accurate to say that an unhealthy lifestyle contributes to those deaths, and that obesity sometimes goes along with an unhealthy lifestyle. Certainly there are people who never exercise, eat junk food, have high stress levels, and die of heart disease who aren’t a single pound overweight. Severe obesity does seem to make other health problems worse, but that’s a far cry from the blanket statement that obesity is a killer disease. Extreme apple-shaped obesity is a special case (it’s mainly men who have this condition), because researchers can show directly how belly fat leads to disease. But even belly fat isn’t an argument for dieting; almost anyone, says Steve Blair, can fight off insulin resistance with regular exercise.
The claim that obesity is the number-two killer in America (after smoking) doesn’t add up in other ways. If being fat is responsible for directly causing so many diseases that lead to early death, then it would follow that as Americans get fatter, more people would be dying from those diseases. But we’re not: The IOM report notes that while obesity is increasing in the United States, the rates of hypertension, high cholesterol, high blood cholesterol levels, and cardiac disease — all supposedly associated with obesity — are declining. (The authors mention this phenomenon only in passing, with no explanation, most likely because it undercuts their argument that obesity is a serious disease.) In other words, we’re getting fatter, but we’re suffering from fewer of the diseases traditionally associated with obesity. Clearly, the relationship between obesity and life-threatening health conditions is not as simple and direct as many people make it seem.
The statistic on obesity costing the country $100 billion a year is similarly suspect. That estimate was also derived, in part, from the Nurses Health Study, and the same criticism — assuming that obesity directly causes disease — applies. The $100 billion figure also includes the estimated $33 billion Americans spend per year on dieting as a “cost,” which is ridiculous; that money isn’t a drain on national resources, but a spur to one particularly healthy sector of the economy — the diet industry.
The health risks of being underweight haven’t been calculated into any of these equations, either. In a 1996 study, David Levitsky and his colleagues at Cornell University analyzed 60 previous studies involving weight and early deaths, involving 357,000 men and 249,000 women (many times more than the Nurses Health Study), and found that the health risks of moderate obesity were exaggerated, while the risks of being underweight have been neglected. For women, there was little relationship between weight and early death at all. For men, after controlling for confounding factors such as smoking and disease, the data showed, if you drew a line on a graph, a U-shaped relationship between weight and early death. Those men who were very underweight were as likely to die early as people who were seriously obese. For everyone between the extremes, weight wasn’t a substantial factor in their death. “The health risks of being moderately underweight are comparable to that of being quite overweight and look more serious than most people realize,” Levitsky said.
Another problem with calling obesity a “disease” is that it suggests that everyone who is fat must be suffering from the same disorder, with the same consequences for their health. In fact, people are fat for different reasons and should be treated accordingly. Some people who are fat, for instance, overeat; others don’t. For some, being fat goes along with a constellation of other health problems; others are perfectly healthy. A measurement of body weight to height alone — BMI — is really too crude to make any conclusions about a person’s health status. Still, most physicians accept that weight is an important indicator of health, and have us step up on the scale first thing.
Physicians warn us to lose weight, in part, because they hate fat just like the rest of us. Obesity, to them, is a disease in another sense of the word: “Absence of ease; uneasiness, discomfort; inconvenience, annoyance,” as the Oxford English Dictionary puts it. Physicians, like many other people, feel uneasy in the presence of someone extremely large, and when they have troubles treating the patient, they feel inconvenienced and annoyed. A London physician in the 1920s expressed the opinion of many of his colleagues when he wrote that all obesity is caused by gluttony and leads to stupidity: “Every degree of alimentary obesity is contemptible, because it denotes self-indulgence, greed, and gourmandizing; and most are disgusting because they represent an unsightly distortion of the human form divine, and a serious impairment of intellectual faculties.” In the 1950s, psychiatrist and eating disorders pioneer Hilde Bruch observed that these negative attitudes, while not so outspoken, persisted. “Many contemporary American physicians, even those who specialize in the treatment of obesity, consider their fat patients a somewhat lower type of humanity.” Several studies in the past decade have shown that many doctors still consider their fat patients weak-willed, ugly, and awkward. In one study of health care professionals, 84 percent thought obese patients were self-indulgent, 88 percent believed they ate to compensate for other problems, and 70 percent assumed they were emotionally disturbed. These attitudes can be quite damaging, since many fat people prefer to forego medical treatment altogether than be subjected to the humiliation that accompanies a doctors’ visit.
Doctors not only share our prejudice against fat, they have the added frustration of not being able to help their patients lose weight. Most physicians genuinely want to help, and all their training has made them believe that they should be able to help someone who seems only to need to eat less, exercise more, and get a little boost with some appetite suppressants. If only their fat patients would follow doctor’s orders, they believe, they’d lose weight. “The physician,” wrote Bruch, “has been indoctrinated with the conviction that obesity is a deplorable condition which should be corrected; and that it is easy to correct if only fat people would follow the excellent advice which is so generously offered to them.” Physicians are frustrated when their treatments fail, and rather than face the idea that the treatments may be ineffective, they blame their patients for being uncooperative, reinforcing their belief that fat people tend to be weak-willed.
But it’s the diet treatments that fail. Fifteen years ago, Yale University psychologist and obesity researcher Kelly Brownell observed that most people stand a better chance of recovering from cancer than losing weight and keeping it off. There is no standard way to treat obesity, the way there are widely accepted ways to treat ulcers, diabetes, or appendicitis. Visit ten doctors and they’ll give you ten different opinions about how much you should weigh and what you should do to get down there. One will recommend a liquid-protein diet, another behavior modification, another a 1,200-calorie-a-day diet, and a fourth diet pills. In the long run, almost nothing works. Despite the optimistic talk about successfully treating obesity, most honest researchers acknowledge that they are years away from really knowing what they’re doing. “All current methods [for reducing weight], from thigh creams to stomach staples, are like gropes in the dark, and as such, are either totally ineffectual or are no more than counterforces to an incompletely understood regulatory disorder,” says Jules Hirsch, a prominent Rockefeller University obesity expert. “There are no cures at this time.”
The idea that obesity is a disease, however, has given physicians license to keep trying unproven, unnecessary and often dangerous obesity treatments. In the imaginations of many physicians, obesity isn’t as hard to cure as cancer, it is cancer. “To call obesity a disease,” says University of Cincinnati eating disorders expert Susan Wooley, “tends to suggest that we should keep all our treatments going even if the success rates are low and carry other risks.” The disease concept makes it seem as if those risks are acceptable even for people who are hardly overweight. Recently, for instance, I asked Steven Heymsfield, an obesity researcher at St.-Luke’s Roosevelt Hospital in New York who is a paid consultant to Nutri/System and helped develop NutriRX, the company’s medical weight loss program, why people who are only 20 percent over ideal weight should be considered candidates for treatment with diet drugs. The drugs — fenfluramine and phentermine — may have unpleasant side effects, cause brain damage in laboratory animals, and in rare cases in humans, cause pulmonary hypertension, a condition that is often fatal. Heymsfield took the long view, telling me that the process of developing diet drugs takes time and inevitably causes some occasional instances of harm, to the greater good. The situation reminded him, he said, of days in an early residency when he worked with children who had leukemia, who suffered terrible side effects from the treatment. “Obesity is not leukemia,” I said. “No,” he replied, “But you get my point.”
The balance of medical risks to benefits has become terribly skewed in obesity treatment. Being overweight is not a serious health risk, and obesity is not a terminal illness. And even if there are considerable health risks to severe obesity, there is no evidence that medical weight loss treatments lessen those risks and improve patients’ health in the long run. There are, however, good indications that those treatments can lead to depression, eating disorders, physically stressful yo-yo dieting, and with some treatments, serious side effects and even death. In no other field of medicine are patients routinely counseled to undergo a treatment that has a less than ten percent success rate, except in oncology, where risky, last-ditch efforts are tolerated because in many cases the patients would otherwise die. “By ordinary standards of scientific discrimination, dieting might well qualify at best as experimental treatment, not valid therapy,” says Baylor University medical ethicist Andrew Lustig. In experimental treatment, there are different rules: patients are informed that there’s a high probability the treatment won’t help them. But with diets, he says, patients are often not informed that the chances of losing weight are low, and that they may be harmed in the process.
It’s also profitable for physicians to keep on treating obesity as a disease. When people hear that obesity is a disease, it scares them into marching straight to their doctor’s office. Inevitably, the more people belive that obesity is a disease, the more they will accept that dramatic medical treatments for the condition — very low calorie diets, surgery, and pills — are better for them than the healthier home remedies of exercising regularly and eating more vegetables.
Many physicians, especially those who specialize in weight loss, encourage, and sometimes advertise, this idea that obesity is a medical condition that should only be handled by doctors. Their patients see them when they feel they’ve finally gotten serious about dieting (as if they were never serious when they plunked down hundreds of dollars at Jenny Craig). They believe that their physician will, at last, prescribe the safest diet, the strongest medicine, the most individualized weight loss treatment, and the latest in “wellness” or “lifestyle maintenance” or whatever else is the current medical marketing phrase.
© Laura Fraser