01.03.13

CDC Researchers Find Lower Mortality Rates Among Overweight People

Don’t skip dessert! A new study finds that overweight—not obese—people have lower overall mortality rates than their thinner counterparts. Dr. Kent Sepkowitz applauds the CDC investigators for straying off-message.

The world of public health was knocked off the rails a bit this week with the release of a study demonstrating that you can, in fact, be too thin. Reviewing 97 studies involving almost 3 million people divided into groups according to weight, researchers at the Centers for Disease Control demonstrated that the overweights—not the obese, but decidedly not the thins or the very thins—had lower overall mortality rates than the rest of the pack.

The finding represents the first momentum shift in a century, since fashion and cinema made thin synonymous with beauty and health. The rout of the public by the thin-ocracy has been so complete that a goal other than blind pursuit of the flat stomach and the sharp jaw seems sacrilegious.

Well, the low body mass index (BMI) hegemony appears to be coming to an end. The findings are clear and simple. Researchers pored over endless studies that previously had examined rates of death in people of various shapes and sizes. And they had a lot to select from: the researchers found more than 7,000 articles in the medical literature that have studied the issue. They placed patients into categories according to BMI (normal, overweight, obese) and ran a series of complex statistical analyses.

Compared to people with a normal weight (a BMI less than 25), the overweight (BMI between 25 to 30) had a 6 percent lower mortality rate—and both groups had a rate about 15 percent lower than the obese, especially the very obese (BMI above 35).

The explanation for the finding is uncertain. Perhaps the pleasantly plump but not obese have an extra reserve—a literal spare tire—that confers a survival advantage should they become seriously ill, whereas the lean-iacs do not. Or maybe the thin ones were thin because of a serious illness that, in the course the various studies, killed them. Or maybe the thin ones were thin because they were chain smokers living off Scotch and potato chips. Or just maybe the occasional pig-out does soothe the soul and make for a happier, healthier individual.

Whatever the explanation, the observation—a truly startling one—stands. Yet the most impressive aspect of the finding is not the fact disclosed. Rather it is the willingness of the CDC investigators to be guided by the data and not by a preconceived notion of the “message.” After all, the public health message for decades has been that big is bad and bigger is worse. Delineation of the current U.S. obesity epidemic has been one of the main accomplishments of the CDC over the last decade.

Perhaps the pleasantly plump but not obese have an extra reserve that confers a survival advantage should they become seriously ill, whereas the lean-iacs do not.

Yet the same group of public health experts who have fought to keep America thinner was willing to stand behind the current study. True, the study strongly demonstrates the lethality of obesity. But the experts also know the take-home may become a definitional haze where “overweight” and “obese” begin to merge and a good-news-stay-fat trope emerges.

Unlike the world of politics, where the “reality-based community” is a term of derision, truth is subjective, and facts, to quote Reagan, are stupid things, in science, the opposite is true. Here, facts are facts and always worth pursuing wherever, as the CDC has shown by publishing this article, they lead you.