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.)