Read more of Daniel Engber's columns on obesity and health care reform.
White people also appear to suffer disproportionately from weight-related illness, as compared with black people. According to Muennig, a black woman who's 5 feet 5 inches and less than 60 years old won't develop any weight-related risk of early death until she reaches 225 lbs. Meanwhile, a white woman of the same height and age group would hit the same threshold at 170 lbs. That fits with the idea that body-size norms differ among blacks and whites. (Black people also tend to be less susceptible to eating disorders and weight-based wage discrimination.)
There are some alternative explanations for these disparities. They might, for example, be an artifact of the crude way in which we measure obesity. Black people tend to have less abdominal fat (associated with cardiovascular disease) than white people given the same BMI reading, and women also tend to have more adipose tissue, and smaller waist-to-hip ratios, than men. But even the most accurate measures of fatness—like dual energy X-ray absorptiometry—don't really improve our ability to predict health outcomes across the population. It may be that the exact volume of adipose tissue in someone's body is less important than the way they look to others. (Muennig suggests that merely having "big bones" could be bad for your health.)
That's not to say obesity won't affect your body, independent of any social factors. As Muennig points out, obese lab rodents aren't likely to suffer much emotional abuse from their fellow mice, but they seem to have higher levels of pro-inflammatory cytokines nonetheless. Still, there's plenty of evidence that body-shape discrimination plays a role in human disease outcomes. Shortness, for example, is associated with an increased risk of coronary heart disease, diabetes, and early death—as well as lower wages and fewer long-term relationships. For some reason, though, the health effects of being short are worse for men than they are for women. Could it be that the social consequences of height and weight go in opposite directions?
If anti-fat bias can affect our bodies, then it's worth considering how an all-out war on obesity plays out in terms of public health. When we reach out to poor communities and educate them about the risks of being overweight, we are, in effect, exporting the weight stigma that happens to be most prevalent among rich, white people. Indeed, Rebecca Puhl says the reported prevalence of weight discrimination has increased by two-thirds (PDF) since the mid-1990s, while media coverage of the "obesity epidemic" has quintupled over roughly the same interval. (Meanwhile, the U.S. diet industry has just about doubled its annual revenues—to nearly $60 billion.)
We've worked hard to frame excess weight as a major health risk and a drain on the economy. The motivation is generous enough: Anti-obesity rhetoric encourages people to eat less and exercise more. But what if it also encourages discrimination? If that's the case, a war on obesity would come at a significant cost to the fattest Americans—in terms of lower wages, less education, and more stress-related illness.
Fat activists argue that the risks of such a policy far outweigh its potential benefits. (They say that doctors should encourage healthy lifestyles instead of trying to enforce an ideal body size.) But few mainstream public-health advocates take such claims seriously. They point out that many interventions in poor communities focus on diet and exercise rather than weight per se. If BMI is used as a measure of success in these programs, that's because it's a quick way to see whether people really are pursuing a healthy lifestyle. For Kelly Brownell, director of the Rudd Center and a leading researcher on both health policy and weight bias, the dangers of discrimination are important but relatively modest. What about the idea that targeting obesity might be counterproductive for the fattest Americans? He doesn't buy it.
The fact is, very few researchers have tried to measure the combined health effects of anti-fat prejudice. Nor have legislators spent much effort on the social consequences of weight stigma. Only a handful of cities—Washington, D.C.; San Francisco, and Santa Cruz, Calif.—have passed laws to protect the rights of obese people, and there's only one state—Michigan—that forbids employers from discriminating on the basis of body size. If you're victimized for being fat anywhere else in the United States, good luck. You can sue your employer under the Americans With Disabilities Act, but you'll have to prove that your weight condition is something like being wheelchair-bound or mentally retarded—not such a good way to reduce weight stigma overall.
Given the risks associated with weight stigma, we should at least reconsider our tendency to blame obesity for the country's health crisis. (I suggested last week that we could target poverty instead.) If obesity prevention measures do end up in the health bill, let's make sure they'll do more good than harm. The Rudd Center has called for a new federal ban on weight discrimination (PDF) or an expansion of the Civil Rights Act. Both would go a long way toward protecting the two-thirds of all Americans who are classified as overweight or obese.