Read more of Daniel Engber's columns on obesity and health care reform.
Just about every discussion of obesity and health care begins with same purported fact: The diseases associated with excess weight are impoverishing the nation with $147 billion in unnecessary medical bills every year. In my last column ("Give Us Your Tired, Your Poor, Your Big Fat Asses …"), I argued that obesity can also make us poor individually, since fat people face rampant discrimination on the job and marriage markets.
A recent paper from Yale's Rudd Center for Food Policy & Obesity hints at the scope of this anti-fat prejudice. We know, for example, that if you're fat, you make less money. Lots of studies have shown how body size plays out in the working world: According to one, women who are two standard deviations (or 64 pounds) overweight suffer a wage penalty of 9 percent (PDF); another found that severely obese white women lose out on one-quarter of their potential income. There's also evidence that obese women are less likely to attend college or maintain romantic relationships, even controlling for socioeconomic background. (One survey found that a few extra pounds could reduce a woman's chance of getting married by 20 percent.)
Heavy people may face discrimination in medical settings, too. The authors of the review, Rebecca Puhl and Chelsea Heuer, cite numerous surveys of anti-fat attitudes among health care workers, who tend to see obese patients as ugly, lazy, weak-willed, and lacking in motivation to improve their health. Doctors describe treating fatties as a waste of time, and the staff at teaching hospitals appear to single them out for derogatory jokes. Unsurprisingly, many obese people avoid seeing their primary care providers altogether, and those who do are less likely to be screened for breast, cervical, and colorectal cancers. (That's true even among those with health insurance and college degrees.)
These data points suggest a rather simple approach to America's obesity problem: Stop hating. If we weren't such unrepentant body bigots, fat people might earn more money, stay in school, and receive better medical care in hospitals and doctor's offices. All that would go a long way toward mitigating the health effects of excess weight—and its putative costs. But there's an even better reason to think that America's glutton intolerance is a threat to public health and the federal budget. Recent epidemiological research implies that the shame of being obese poses its own medical risk. Mental anguish harms the body; weight stigma can break your heart.
The victims of chronic stress or depression, whatever their size, tend to maintain higher levels of certain inflammatory chemicals in their bloodstream. Under normal circumstances—and over the short term—these cytokines help to control the body's response to dangerous situations like injury or illness. The chemicals create their own problems, though, when they stick around too long. A sustained or elevated stress response seems to increase your risk of heart disease, hypertension, and diabetes. That may explain some of the relationships between health and wealth: Blood tests show unusual cytokine activity among those of low socioeconomic status as well as patients with post-traumatic stress and panic disorders.
It turns out that obese people have unusual cytokine readings, too, and these are often taken as the cause of weight-related illness. According to one theory, the presence of visceral fat cells can set off a biochemical chain reaction that leads to the inflammatory response. (Fat cells may even secrete the cytokines themselves.) As a result, someone who's fat and someone who's chronically stressed will be at risk for many of the same diseases.
It may be that obesity and stress are independent risk factors that happen to affect the body in similar ways. Or maybe chronic stress leads to weight gain, which in turn causes inflammation. According to epidemiologist Peter Muennig, there's another pathway from excess weight to disease. In his 2008 paper "The Body Politic: The Relationship Between Stigma and Obesity-Associated Disease," Muennig argues that the stress and shame of being fat causes those cytokine abnormalities. In other words, obesity makes you sick by stressing you out.
According to Muennig's theory, the health effects of obesity should vary with the intensity of anti-fat bias—the more abuse you take, the worse the disease. Women are more likely than men to have eating disorders, and they face greater weight-based discrimination in the overweight range. (According to Puhl, men get harsher treatment when they're really obese.) And, sure enough, women are seven times more likely to experience significant illness or death as a result of being overweight. (Obese women are especially vulnerable to clinical depression, which is itself a risk factor for cardiovascular disease.)
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.