CDC Backtracks on Obesity: Fat is Bad Again

June 3rd, 2005 by

Back on April 22 we blogged the new food pyramid model and a surprise finding from the AMA Journal that a little obesity might actually help you live longer. That particular study found that skinny people were at higher risk for death than those who were somewhat overweight. So it was time to break out the Twinkies and have a party, right?
Not so fast. It turns out that a little obesity is still a bad thing. On June 2 the Centers for Disease Control held a briefing that essentially retracted the findings of that earlier study. Dr. Julie Gerberding, head of the CDC, is quoted as saying: “we want to be very clear–obesity and overweight–and I’m sorry to say overweight because I know a lot of people were hoping that CDC was going to come out and say it was okay to be overweight but we’re not saying that. It is not okay to be overweight.”
Got that? Overweight was, is and will be a bad thing. Gerberding goes further, asserting that “people need to be fit ,they need to have a healthy diet, and they need to exercise and overweight is a very important health issue in and of itself, but also overweight is a major predictor of future obesity.” In other words, don’t let that gym membership lapse any time soon.
Good Data Gone Bad
Naturally, the question that interests the Insider most is how did this unfortunate endorsement of obesity come about? This isn’t exactly Enron — so cooking the books doesn’t raise the value of anyone’s stock. (Then again, did anyone track the value of fast food stocks when the initial report came out?) Where exactly did the data crunchers go wrong? It turns out that in studying morbidity, the research data brought in a large number of people who died of from chronic conditions, for example, people who had end-stage cancer or an immunodeficiency. These terminally ill and finally deceased people very often are, by the time they die, significantly underweight. As a result, the deaths involving the chronically diseased skewed the data in favor of moderate obesity, which creates health problems but does not generally kill people outright.
So when you just compare death rates of “skinny people” to people who are slightly overweight, you can get a paradoxical finding. It’s literally true, but it really has nothing to do with the root causes of mortality. (Kind of like saying that every accident is the result of “carelessness.”) The Insider is somewhat shocked that the earlier study was released without further scrutiny. Fortunately, we did not adjust our dietary intake to accommodate the counter-intuitive findings. So we’ll continue to pass on the General Gau’s Chicken (sigh) and stick with the steamed vegetables. Bon appetit!