Is is okay to be fat?

Now that I have managed to reduce my BMI from an obese 31 to a healthy 20 (19 actually–I am having trouble keeping my weight up now, which is extremely weird), I came across an article in Scientific American that asks “Can Fat Be Fit?”

The author references a much-quoted study by Katherine Flegel of the Centers for Disease Control that suggests that people who carry a little extra weight are actually less likely to die than people with a “healthy” weight [1]. The SciAm article refers to a criticism of Flegel’s methods by Meir Stampfer, of the Harvard School of Public Health. According to Stampfer, Flegel’s “healthy weight” sample included smokers, people with cancer, and others whose weight was more of a reflection of their poor health than vice versa.

Flegel seems to have taken note of such criticisms, and published another study this month in which she corrects for the health history of her participants [2]. She and her colleagues conclude that “The relative risks for BMI categories did not show large or systematic changes after simultaneous exclusion of ever smokers, persons with a history of cancer or cardiovascular disease, and persons who died early in the follow-up period or had their heights and weights measured at older ages.”

These discussions, and similar controversies about the role of cholesterol in heart disease, are great examples for discussing inferences drawn from correlational data with students. We surely are not going to randomly assign infants to obese, overweight, and healthy weight groups and then wait to see what happens. So we are left with correlations–people with high cholesterol levels and obesity seem more prone to life-threatening diseases. But this is no simple relationship.

In the meantime, a certain amount of common sense should prevail. Sure, my hubby and I received glowing results from our annual physicals, but the most important point is how we “feel.” Being slim is simply more comfortable, whether you are walking, sitting, or sleeping. I like the energy levels. I look like “me” again. We are so determined to never go back that we took EVERYTHING out of our closets that is larger than our current sizes (32s for Roger, size 4 for me) to Goodwill. Oh darn, I guess I’ll have to go shopping for school clothes now….

1.  Flegel, K.M. et al. (2005). Excess Deaths Associated with Underweight, Overweight, and Obesity. Journal of the American Medical Association, 293, 1861–1867.

2.  Flegel, K.M., Graubard, B.I., Williamson, D.F., & Gail, M.H. (2007). Impact of smoking and preexisting illness on estimates of the fractions of deaths associated with underweight, overweight, and obesity in the US population. American Journal of Epidemiology, August 9 [epub ahead of print].