WHAT MADE AMERICA FAT?

Go on a Diet, Gain Weight

Here’s a paradoxical possibility. Maybe the nation’s obesity statistics were swelled not mostly by rich eats, but by avoidance of such foods. A great deal of evidence points in that direction, not the least of which are studies that find a strong correlation between dieting and being obese. Not merely a reflection of the fact that lots of overweight people are on diets, the correlation signals that, as a group of Harvard and Stanford researchers observed, for substantial numbers of people, “dieting to control weight is not only ineffective, it may actually promote weight gain.”

The researchers made that assertion in a paper in the journal Pediatrics, where they reported the results of a study of almost fifteen thousand boys and girls between the ages of nine and seventeen. Over the three years the researchers followed the kids, the dieters in the sample gained more weight than the nondieters and were more likely to engage in binge eating.

Other research also suggests that dieters and those who encourage dieting bear more than a little responsibility for the obesity epidemic. For example, the University of Minnesota team who conducted the fast-food study found in a separate survey that adolescent boys whose mothers encouraged them to diet were significantly heavier than their peers whose mothers left them alone about their weight, and seven times more likely to engage in binge eating.

Another set of studies finds young girls are more likely to become overweight or obese later in life if their parents put them on diets by restricting them from eating “junk” foods.

In surveys of obese adults, social scientists at the University of California came upon further evidence of the fattening effect of dieting. Instead of looking at young dieters to see if they were more likely to get fat, these researchers asked obese adult women when they had started dieting. Nearly two-thirds had gone on their first diet before age fourteen, and the heaviest women in the study had dieted earlier and more often than the rest.

“For this group of women, dieting has actually promoted their obesity,” Joanne Ikeda, the lead researcher on that study and former director of the Center for Weight and Health at the University of California, Berkeley, reported. Noting that the number of obese and overweight Americans increased at the same time that dieting became commonplace, Ikeda made the obvious point: “One has to wonder, is there not a link between the two?”

In Losing It, her exposé of the $50 billion diet industry, author Laura Fraser identified the likely link. Bingeing. “When we starve ourselves, our bodies call out for help with hunger pangs and cravings, and our minds plot a rebellion,” she wrote. “Diet foods, in particular, make us want to overeat. When we eat diet foods, they’re usually a cheap substitute for ‘bad’ foods, and we aren’t really fooled. We end up overcompensating for our desires, eating more of the diet food than we should, looking for satisfaction.”

Lose Weight, Become a Hermit

By denying ourselves high-fat foods, high-carb foods, fast foods — or whatever the prevailing diet orthodoxy prohibits — we may be doing little to bring down the country’s gross tonnage. Rather than give up pleasurable foods, maybe we ought to forsake other things that studies have shown to be associated with weight gain: going to church, for example, or dining in groups.

Researchers at Brown, Purdue, and Cornell universities discovered that church members are more likely to be overweight than the rest of us, and the most religious Americans have especially high rates of obesity. Although social scientists who study the matter have not nailed down the link between religiosity and fat, they have some likely candidates. They note, for instance, that people who are more religious have lower rates of smoking.

Active churchgoers have also been known to frequent those church socials I mentioned before, where in addition to lots of food, there are lots of eaters, a known risk factor for obesity. The more people present at a meal, the more they tend to eat, studies find.

There may be another reason to stay away from crowds as well. Research by a group of scientists at Wayne State University suggests obesity may be caused by a coldlike virus called adenovirus.

These biomedical researchers are serious. The idea of “catching obesity” may sound like the premise for a Saturday Night Live skit, but the Wayne State scientists have found that overweight people are four to six times more likely to have the adenovirus than leaner folks. What’s more, when they inoculated chickens, monkeys, and mice with an adenovirus, the animals gained weight and body fat without eating more.

The researchers contend that the spread of this virus or its cousins may explain why rates of obesity have been rising throughout the world in recent years. They point out that obesity would not be the first condition long thought to result from a bad diet and lifestyle that turns out to be caused by microbes. Ulcers, now understood to be caused by a bacterium, are an example, and pathogens have been implicated in heart disease as well.

America’s Number Two Killer?

The deeper I burrowed through the theories of obesity, the more of them I found.

I also found myself entertaining an irreverent thought. How much does it really matter that Americans are getting fatter? To the diet industry, it matters a great deal, but the profit motive aside, does plumpness really deserve all the attention and resources we devote to it?

Many of the theories of obesity are fascinating, to be sure, but with nearly two-thirds of Americans overweight or obese, their body types are now the norm, and medical science does not usually concern itself with trying to understand and prevent what has become the norm. Americans have also grown taller in the recent past (about four inches on average since the late 1800s), but little attention is devoted to that change, which conventional wisdom also attributes to changes in diet. Corporations and government agencies do not push pills, programs, or special menus for height control, even though tall people are more prone to an array of ailments, from orthopedic maladies to several types of cancer.

Government officials and journalists justify their fixation on weight with debatable claims about the lethality of fatness. “Obesity on Track as Number One Killer,” read the front-page headline on a USA Today story in 2004. Reporting on a study in the Journal of the American Medical Association (JAMA) that attributed 385,000 deaths a year to overweight and obesity, the story concluded with a quote from Julie Gerberding, one of the study’s authors and director of the Centers for Disease Control. Americans need to learn to eat “healthy foods in healthy portion sizes and find ways to incorporate exercise into their everyday lives,” she admonished.

That Americans had been getting more exercise and eating more fruits and vegetables and less fat during the period when obesity rates shot up apparently didn’t faze Gerberding. But some of the top obesity researchers within her own agency fumed when they saw the JAMA article blaming obesity and hundreds of thousands of resultant deaths on “poor diet and physical inactivity.”

“Everyone is really angry right now; this is a big scandal,” a prominent researcher at the CDC told me soon after the article came out. She and some of her colleagues don’t buy the claim that obesity and overweight are top killers. “A lot of the research centers at CDC wouldn’t approve the article,” she said. “There were protests about the methodology and the data, but the authors ignored all input from everyone else at CDC and went ahead with this stuff. Their argument doesn’t even make sense, because you can be fat and have a good diet and be physically active, and you can be thin and have a poor diet and be sedentary.”

I’ll refer to this scientist as Dr. Diver. An eminent obesity researcher whose own papers have appeared in top medical journals and are cited hundreds of times in the obesity literature, she spoke with me on the condition that I not use her name. (Government researchers are prohibited from making public statements that contradict their agency’s official position.)

Diver called to my attention a couple of basic facts that undermine the idea that obesity is a major killer. Life expectancy has increased during the obesity epidemic. And most people die old. Three-quarters of people who die are over sixty-five, and 40 percent of deaths are people over eighty, Diver pointed out. “So the important question about the effect of obesity on death rates,” she said, “is in old people, and the evidence suggests obesity is almost irrelevant there.”

Highly critical of studies purporting to show that young people sacrifice years of their lives by being fat, Diver directed me to another study published in JAMA: “Years of Life Lost Due to Obesity.” This study declared that highly obese white men in their twenties will lose thirteen years of life because of their weight—an eye-catching claim that was picked up by the news media and has been cited in numerous other journal articles. But when Diver examined the survey on which it was based, she came upon something curious. “I looked at that paper and said to myself, ‘How many guys like this could there be in that data set?’ I know those data sets well, and the answer is, there aren’t any. There are no white males between twenty and twenty-nine with BMI’s that high in those surveys. The finding is bogus.”

Lacking actual people in that age group and weight range, Diver explained, the researchers based their conclusion on hypothetical models. When Diver herself looked at the same data (the government’s National Health and Nutrition Examination Surveys) she discovered that, in fact, a large proportion of healthy people are overweight.

Far from being the only authority who disputes the party line about the causes and consequences of weight gain, Diver is one of a dozen well-informed skeptics I came upon: physicians at major medical associations, research scientists with government agencies, and professors at leading universities. They all concur with an epidemiologist I interviewed from another division of the Department of Health and Human Services. “The evidence is just not there,” he said, “to support the claim that if a healthy person maintains his weight at a so-called normal level all his life he will add years to his life span.”

Indeed, in a paper published in JAMA in 2005, four preeminent statisticians from the CDC and the National Cancer Institute showed that people officially classified as overweight actually have lower death rates than “normal” and “underweight” people. Using nationally representative data collected from 1971 through 2002, they established that while the truly obese do have higher death rates, the number of deaths attributable to obesity is about 112,000, less than one-third the number the CDC chief had been publicizing.

The Weight- Centered View of the Universe

Nor, say the skeptics, do thin folks protect themselves from many of the ailments that government officials and health columnists have attributed to corpulence. No one denies that weight is a factor in type 2 diabetes or that extremely obese people suffer serious health problems as a result of their weight. But the critics offer good reasons to question whether mildly overweight people lower their odds of heart disease or cancer by dieting.

“We talk about all these so-called obesity-related diseases, but that’s not really their major cause,” Dr. Diver told me. “Some are age-related diseases, and for some, such as heart disease, obesity is just one risk factor among many risk factors and not necessarily the most important nor the cause. I call this the weight-centered view of the universe: weight causes all the problems. If you actually look at the data, you find that everybody who is overweight and has hypertension, for example, would probably still have it regardless of their weight, because it’s an age-related condition.”

When critics dare to raise those sorts of matters publicly, or thodox obesity researchers treat them dismissively. In 2004, after Paul Campos, a law professor at the University of Colorado, published his copiously documented book, The Obesity Myth, advocates of the reigning dogma responded like politicians. They ignored the challenger except when journalists compelled them to comment.

It was in response to a request from USA Today that Walter Willett, the Harvard professor of nutrition, commented on The Obesity Myth, and his remarks could hardly have been more derisive. Rather than address Campos’s arguments and evidence, Willett wrote him off as “one lawyer with no experience and no medical training.”

In response to a question from the reporter about whether being overweight leads to serious illness, Willett repeated the claim that “there’s a strong relationship between extra body weight and heart disease,” though, as Campos and other skeptics emphasize in their writings, the number of deaths due to heart disease plunged rather than rose during the obesity epidemic. The skeptics cite as well autopsy and angiography studies that directly examine people’s hearts and report no association between body weight and heart disease.

If Willett’s side has convincing evidence to refute its critics on these points, I couldn’t find it. After the USA Today piece came out, I e-mailed Willett for studies showing that extra weight increases the risk of heart disease. He replied not with a bibliography but with a citation of one of a pair of papers he published in 1995 about weight and heart disease, and a couple of caveats. “This is just one study,” he wrote, “and there is a vast literature on this. Campos either can’t read or is purposely deceiving his audience.”

My high school debate coach taught me to ignore ad hominem attacks, which he said are a sure sign of a weak case. So I disregarded Willett’s characterization of his opponent and went in search of the vast literature to which he referred. And sure enough, I had no problem locating papers that assert a correlation between increasing weight and heart disease. Many were at pains to emphasize, however, that “the increased cardiovascular risk associated with obesity is applicable in only a minority of the obese subjects,” as a group of Swedish researchers noted in a paper in 2002 in the International Journal of Obesity. In their twenty- three- year study of more than twenty- two thousand men, the scientists found that even though, as a group, overweight and obese men had more coronary incidents than other men, fully 90 percent had none. Nearly all of the added risk of heart disease among the obese is due to factors other than the weight itself, the researchers found, such as high cholesterol or hypertension.

As near as I can tell, not a single published study demonstrates that heart disease among the overweight and moderately obese results from their heft rather than from other factors that contribute to obesity and heart disease, such as smoking, poverty, stress, genetic predisposition, physical activity, depression, and quality of medical care.

The papers to which Willett sent me directly certainly do not settle the matter. Products of his Nurses Health Study, they take into account few of the many pertinent factors. With a sample of women all employed in the same profession, 95 percent of them white, Willett and his research team have no way to assess some of the alternative explanations. They do acknowledge theimportance of smoking, but that leads them to exclude smokers from their analysis, which leaves them with a relatively small sample. Of the 115,195 women in the study, only 184 were nonsmokers who died of cardiovascular disease during the sixteen years of study.

In a paper published in the New En gland Journal of Medicine in 1995, Willett and his colleagues reported a 60 percent increase in the death rate from cardiovascular disease for nurses who were moderately overweight (BMI of 27 to 29) compared to slender nurses (BMI under 22). That sounds like an alarming number. But how many actual people does it represent? Willett’s team divided the 184 nurses into seven separate subgroups by weight. Presumably, even the largest of the subgroups had no more than two or three dozen women. With numbers that small, it would take only a few extra deaths of women in the overweight subgroup to produce the seemingly shocking statistic.

I don’t know the exact number of nurses involved, because Willett wouldn’t provide me with data to compute it. “Unfortunately, many of the detailed numbers you request are not in the published papers; editors are notoriously reluctant to include all the details we would like to publish,” he replied to an e-mail in which I asked where I could find some of the information missing from his papers. When I followed up with a request for someone on his staff to pass along the numbers, he wrote back, “I would like to help you, but we don’t have someone to do that; we have asked the National Institutes of Health for such funds.”

Money Triumphs over Fat

Willett was equally unhelpful in response to my request for studies that support another of his assertions in the USA Today debate, that “many people manage to reduce their weight by careful diet and regular activity.”

Paul Campos and other skeptics contend that regardless of who is right about whether being overweight causes heart disease, Willett’s side does a disservice by advising that anyone can slim down by cutting back on disapproved foods and becoming more active. In reality, say the critics, only a small proportion of people succeed in taking off much weight and keeping it off.

My review of the research literature supports that conclusion. In an article in the New En gland Journal of Medicine in 2002, for example, physicians from obesity programs within the National Institutes of Health report that people who devotedly diet, exercise, and get counseling for four to six weeks can expect to lose 5 to 10 percent of their weight. But echoing the conclusions of studies I mentioned earlier, they add: “For the vast majority of persons, weight loss is followed by a slow, inexorable climb to the preintervention body weight—or even
higher.”

When I e-mailed Willett for evidence supporting his more optimistic conclusion, he had little to offer. “There is abundant evidence that many people do control their weight; for example, the rate of obesity in groups with higher education is only half that of low-education groups. These are the folks I see running along the Charles every morning,” he wrote, as if one can generalize from genteel joggers in Cambridge to how other Americans would look if they ate less and ran more.

College graduates may be thinner for any of a number of reasons, including, as we’ve seen, their genes and their insulation from chronic stress. Or maybe the lower average BMIs of America’s elite indicate only that “in America, money triumphs over the most resistant fat, which eventually succumbs to regimens that only the very rich, or the fanatical, can afford,” as the Cornell University literary critic Richard Klein has argued. Wealthier Americans certainly have more time and money to go to extreme lengths in pursuit of thinness—a pursuit that is as much about preserving their social position as protecting their health. In the past, when food was scarce, a big belly was a mark of wealth, status, and attractiveness, as is a flat stomach now that most of the population can afford double cheeseburgers.

In the eyes of many, slenderness is a sign of discipline and healthiness, but skeptics reasonably question whether that selfserving presumption ought to be imposed on the entire population by way of ultimatums to shed pounds. Healthy people who lose weight do not live longer than those who do not, studies find. A high but stable weight is safer than repeated fluctuations, and research suggests that yo-yo dieting damages the immune system and may increase the risk of heart disease and type 2 diabetes.

Blinded by the Lithe

In 1998, the physician editors of the New En gland Journal of Medicine wrote an editorial about obesity. Their overall conclusions accord with my reading of more recent studies as well. “Given the enormous social pressure to lose weight, one might suppose there is clear and overwhelming evidence of the risks of obesity and the benefits of weight loss. Unfortunately, the data linking overweight and death, as well as the data showing the beneficial effects of weight loss, are limited, fragmentary, and often ambiguous,” Jerome Kassirer and Marcia Angell wrote.

Lamenting the fact that “many Americans are sacrificing their appreciation of one of the great pleasures of life—eating,” Kassirer and Angell rejected the fiscal model of obesity as simplistic and endorsed in its place a “set point” theory of body weight. In this view, each of us is genetically programmed to be within a particular weight range, and our central nervous system defends that set point by altering our appetite or metabolism if we try to drop or add much weight. The set point can be overridden temporarily by zealous dieting and exercise, but as the editors note, “when these extreme measures are discontinued, body weight generally returns to its preexisting level.”

Noting that “in this age of political correctness, it seems that obese people can be criticized with impunity, because the critics are merely trying to help them,” Kassirer and Angell called on doctors to help end discrimination against overweight people. Their plea is warranted not only on humanitarian grounds (studies document persistent discrimination by teachers, college admissions officers, employers, and health care providers), but for medical reasons as well. A body of research shows that discrimination itself has negative effects on people’s health.

Talk about a vicious cycle: the stress, social isolation, and lower education and income levels engendered by discrimination leave people more prone to weight gain, and thus to more discrimination.

Focused on diet and exercise, many researchers, journalists, and policy makers fail to take sufficient notice of this cycle. Their myopia blinds them to another important contributor to obesity and disease among low-income Americans as well: food insecurity. According to Greg Critser, lower-income Americans are fatter because, unlike the rich, “the more insightful and longer-living of whom have understood that the price of abundance is restraint,” poor folks overeat and underexercise. But in reality, it is people who periodically face the prospect of not having enough to eat who have the highest rates of obesity.

As it happens, neither part of Critser’s statement is accurate. Wealthy Americans are far from restrained in their consumption patterns—witness their SUVs and oversize homes. And large-scale studies show that those who suffer from food insecurity are more likely to be overweight than others of the same age, ethnicity, and income level. Exactly how food shortages lead to obesity is hotly debated, but the fiscal model can’t account for the seeming paradox. In a study where researchers compared people with similar diets and levels of physical activity, they found that those experiencing food insecurity were more apt to be overweight.

Rather than sloth and high-calorie foods, the primary culprit in obesity among the food-insecure may be one we met earlier: binge eating. The eating patterns of people who periodically run low on food resemble those of dieters, albeit for different reasons. When their food stamps run out, their kids’ medical expenses use up the food budget, or the local food bank shuts down, they eat very little. Then, once food becomes available again, they binge. Over time, their bodies adapt to the alternations by converting more of what they eat to body fat.

That millions of men, women, and children go hungry in one of the wealthiest countries in human history is a shameful reality. That this and other critical problems in America’s food system get obscured from public view by bloated concerns over issues like obesity is all the more disgraceful.

By Barry Glassner in "The Gospel of Food - Everything you Think you Know About Food is Wrong", Harper Collins,USA, 2007, excerpts pp.186-199. Adapted and illustrated do be posted by Leopoldo Costa.