Skeptical About the "Obesity Epidemic"

 
John Sullum on reasononline reviews two new book on obesity [Lay Off the Fatties]. The books are "Fat Politics: The Real Story Behind America’s Obesity Epidemic" by J. Eric Oliver and "The Diet Myth: Why America’s Obsession With Weight Is Hazardous to Your Health" by Paul Campos. Here's the opening prargraph of an excellent review, ....

The government seems to have made tremendous strides in its War on Fat. In 2004 researchers at the U.S. Centers for Disease Control and Prevention (CDC) said “poor diet and physical inactivity” were killing 400,000 Americans a year, a number that was widely presented as an estimate of “obesity-related deaths.” Just one year later, the estimate had been reduced to about 100,000. To cut the death toll by 75 percent in the space of a year, the anti-fat crusaders must be doing something right.

I'm not a big fan of diet books or any of the lifestyple books that are so common in the bookstores. These two books are probably not much different, but at least they raise an important issue. How much can we trust the headlines? Is there a real problem with obesity in our society?

It turns out that the "reduction" in deaths was entirely due to rational thinking in the face of stupidity. The orignal report of 400,000 deaths per year was as much as the combined total of all deaths due to disease. A bit of common sense prevailed and the Journal of the American Medical Association published a revised estimate of 112,000 deaths per year due to obesity. (Is that a peer-reviewed journal? If so, where were the peer reviewers the first time?)

What about the obesity epidemic? Well, it turns out that part of it is completely artificial. Back in 1985 you were considered obese if your BMI was above 27.5. A couple of years later the threshold was lowered to 25 making millions of American obese overnight. Neat trick, eh?

There's much more,

“Nearly all the warnings about obesity are based on little more than loose statistical conjecture,” says Oliver, adding that there is no plausible biological explanation for most of the asserted causal links between fatness and disease. “The health risks associated with increasing weight are generally small,” says Campos, and “these risks tend to disappear altogether when factors other than weight are taken into account.” For example, “a moderately active larger person is likely to be far healthier than someone who is svelte but sedentary.” Campos cites research finding that obese people “who engage in at least moderate levels of physical activity have around one half the mortality rate of sedentary people who maintain supposedly ideal weight levels.” Lest you think these facts have been noticed only by political scientists and law professors, Campos and Oliver draw heavily on the work of biomedical researchers such as Case Western nutritionist Paul Ernsberger, University of Virginia physiologist Glenn Gaesser (author of the 1996 book Big Fat Lies: The Truth About Your Weight and Your Health), and Steven Blair, the physician/epidemiologist who heads the Dallas-based Cooper Institute.

I don't know if Campos and Oliver are correct but what they say makes sense to me. The whole obesity epidemic nonsense has a bad smell. It doesn't make sense to this skeptic. Here are some examples of distorted science.

Yet none of this contradicts the main scientific point of these two books, which is that the public health establishment, abetted by a credulous and alarmist press, has greatly exaggerated both the strength of the evidence linking fatness to sickness and the level of risk involved. Oliver cites a 2004 New York Times story headlined “Death Rate From Obesity Gains Fast on Smoking,” based on the highly implausible 400,000-death estimate that was later repudiated by the CDC. He also mentions a 2003 A.P. article that announced “Obesity at Age 20 Can Cut Life Span by 13 to 20 Years.” He notes that “the obesity in question was at a BMI of 45 [305 pounds for an average-height man], which affects less than 1 percent of the population.” In a passage that could have been lifted from a critique of U.S. drug policy, Campos says “the basic strategies employed by those who profit from this war are to treat the most extreme cases as typical, to ignore all contrary data, and to recommend ‘solutions’ that actually cause the problem they supposedly address.”

We need more debate on this issue. We need more skeptics.