I have a bad cold today; I feel like my head’s stuffed with cotton, and I have next-to-no ability to concentrate for more than a few minutes at a time. So rather than attempt to write an original post, I’m going to quote from an excellent article from The New Republic about fat, health, and weight-loss. It’s an excellent article, and I’d highly recommend reading the whole thing.
What accounts for the conflict between studies that claim being “overweight” is a significant health risk and those that suggest such weight levels might actually be optimal? The biggest factor is that researchers fail to point out that, in practical terms, the differences in risk they are measuring are usually so small as to be trivial. For example, suppose that Group A consists of 2,500 subjects and that over the course of a decade five of these people die from heart attacks. Now suppose that Group B consists of 4,000 subjects and that five members of this group also die from heart attacks over the same ten-year span. One way of characterizing these figures is to say that people in Group A are subject to a (implicitly terrifying) 60 percent greater risk of a fatal heart attack than those in Group B. But the practical reality is that the relevant risk for members of both groups is minuscule. Indeed, upon closer examination, almost all studies that claim “overweight” people run significantly increased health risks involve this sort of interpretation (or, less generously, distortion) of their data. [...]
In a decided majority of studies, groups of people labeled “overweight” by current standards are found to have equal or lower mortality rates than groups of supposedly ideal-weight individuals. University of Virginia professor Glenn Gaesser has estimated that three-quarters of all medical studies on the effects of weight on health between 1945 and 1995 concluded either that “excess” weight had no effect on health or that it was actually beneficial. And again, this remains the case even before one begins to take into account complicating factors such as sedentary lifestyle, poor nutrition, dieting and diet drugs, etc. “As of 2002,” Gaesser points out in his book Big Fat Lies, “there has not been a single study that has truly evaluated the effects of weight alone on health, which means that ‘thinner is healthier’ is not a fact but an unsubstantiated hypothesis for which there is a wealth of evidence that suggests the reverse.”
And from later in the article….
If fat is ultimately irrelevant to health, our fear of fat, unfortunately, is not. Americans’ obsession with thinness feeds an institution that actually is a danger to Americans’ health: the diet industry.
Tens of millions of Americans are trying more or less constantly to lose 20 or 30 pounds. (Recent estimates are that, on any particular day, close to half the adult population is on some sort of diet.) Most say they are doing so for their health, often on the advice of their doctors. Yet numerous studies–two dozen in the last 20 years alone–have shown that weight loss of this magnitude (and indeed even of as little as ten pounds) leads to an increased risk of premature death, sometimes by an order of several hundred percent. By contrast, over this same time frame, only a handful of studies have indicated that weight loss leads to lower mortality rates–and one of these found an eleven-hour increase in life expectancy per pound lost (i.e., less than an extra month of life in return for a 50-pound weight loss). This pattern holds true even when studies take into account “occult wasting,” the weight loss that sometimes accompanies a serious but unrelated illness.
And here’s a point I wish Campos had developed further:
Americans… long to believe that medical experts can solve the problem of their expanding waistlines. The reason for this can be summed up in six words: Americans think being fat is disgusting. That psychological truth creates an enormous incentive to give our disgust a respectable motivation. In other words, being fat must be terrible for one’s health, because if it isn’t that means our increasing hatred of fat represents a social, psychological, and moral problem rather than a medical one.
Again, I recommend reading the whole article.