Apparently, This is Why You're Fat
Evidence has been steadily accumulating that certain hormone-mimicking pollutants, ubiquitous in the food chain, have two previously unsuspected effects. They act on genes in the developing fetus and newborn to turn more precursor cells into fat cells, which stay with you for life. And they may alter metabolic rate, so that the body hoards calories rather than burning them, like a physiological Scrooge. “The evidence now emerging says that being overweight is not just the result of personal choices about what you eat, combined with inactivity,” says Retha Newbold of the National Institute of Environmental Health Sciences (NIEHS) in North Carolina, part of the National Institutes of Health (NIH). “Exposure to environmental chemicals during development may be contributing to the obesity epidemic.” They are not the cause of extra pounds in every person who is overweight—for older adults, who were less likely to be exposed to so many of the compounds before birth, the standard explanations of genetics and lifestyle probably suffice—but environmental chemicals may well account for a good part of the current epidemic, especially in those under 50. And at the individual level, exposure to the compounds during a critical period of development may explain one of the most frustrating aspects of weight gain: you eat no more than your slim friends, and exercise no less, yet are still unable to shed pounds.
The new thinking about obesity comes at a pivotal time politically. As the debate over health care shines a light on the country’s unsustainable spending on doctors, hospitals, and drugs, the obese make tempting scapegoats. About 60 percent of Americans are overweight or obese, and their health-care costs are higher: $3,400 in annual spending for a normal-weight adult versus $4,870 for an obese adult, mostly due to their higher levels of type 2 diabetes, heart disease, and other conditions. If those outsize costs inspire greater efforts to prevent and treat obesity, fine. But if they lead to demonizing the obese—caricaturing them as indolent pigs raising insurance premiums for the rest of us—that’s a problem, and not only for ethical reasons: it threatens to obscure that one potent cause of weight gain may be largely beyond an individual’s control.
