So I’ve been meaning for a long time to do a long, comprehensive post on this subject, but I kept putting it off and soon I’ll be busier than normal in my real life, so I’m just going to do the quick(er) version.
Status and type of stress make a big difference in how stress affects you. I first saw this specifically articulated in this Wired article.
While doctors speculated for years that increasing rates of cardiovascular disease in women might be linked to the increasing number of females employed outside the home, that correlation turned out to be nonexistent. Working women didn’t have more heart attacks. There were, however, two glaring statistical exceptions to the rule: Women developed significantly more heart disease if they performed menial clerical work or when they had an unsupportive boss. The work, in other words, wasn’t the problem. It was the subordination.
The connection to fat stigma seems obvious. Not only does being fat lower your social status, many of the diseases listed are also linked to BMI:
While stress doesn’t cause any single disease — in fact, the causal link between stress and ulcers has been largely disproved — it makes most diseases significantly worse. The list of ailments connected to stress is staggeringly diverse and includes everything from the common cold and lower-back pain to Alzheimer’s disease, major depressive disorder, and heart attack. Stress hollows out our bones and atrophies our muscles. It triggers adult-onset diabetes and is a leading cause of male impotence. In fact, numerous studies of human longevity in developed countries have found that psychosocial factors such as stress are the single most important variable in determining the length of a life. It’s not that genes and risk factors like smoking don’t matter. It’s that our levels of stress matter more.
Daniel Engber has also noted that stigma may be a major factor in the correlation between these diseases and BMI:
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.)
Engber also notes, however, that lab rodents, presumably not socially affected by their BMI, have increased levels of cytokines in their blood at high BMIs (and, presumably, higher levels of the diseases correlated with both BMI and stress). Meaning, the effects of BMI are probably not exclusively due to stigma. I would like to find out more about this. How are they getting the rodents to be obese? If through manipulation of the environment, what direct effects does that manipulation have? If through genetic changes to the mice, does preventing or reversing obesity in those mice improve their health, or are both the health problems and the obesity caused by the genes? Maybe this has already been hashed out in experiments, but I also wouldn’t be surprised if no one thought it was worth investigating, since “everyone knows” the way causality works on this issue.
The best way to measure the effect of fat stigma on human health would be to compare societies where there is no fat stigma at all to ones where there is significant fat stigma. But the spread of Western culture is also spreads fat stigma, and I’m not sure that you could control for all the other factors that would differ between societies. Still, you could compare mortality rates between individuals within that society, and find out if there’s any relationship with BMI. But there would still be problems. If being fat helps you survive a heart attack if you do get one, for example, does that mean that without Western medicine, skinny people have an even greater disadvantage when hit with heart disease, since they have nothing but their body to rely on to heal? Or does it mean that fat people respond better to Western medicine, giving them less of an advantage without Western medicine?
In the end, though, whether and how much effect fat and BMI itself has on health does not change the fact that we have plenty of reason to be concerned about the effect of fat stigma on health, both mental and physical.
ETA: Also see this little bit about The Longevity Project WRT status and stress:
Friedman and Martin say it’s the kind of stress that matters. The bright boys selected for the study who ended up having low-status jobs—streetcar conductor, baker, porter—and whose careers did not match their early promise were far more likely to die before age 60 than their higher status counterparts. Success, even in challenging jobs with demanding hours and responsibility, is a tonic.