Ask the doctor: My waist has expanded but I haven't gained weight. Is this because I've stopped wearing a belt?

Q. The article in your December 2014 issue about women's waistlines expanding the past few years intrigued me, because I have experienced an increase, and I have not gained weight. My theory is that the styles of the past few years—pants riding low on the hips, no belts at the waist, and loose shirts—may have caused my waist to increase from 24 to 25½ inches. I am 59 years old, so it also could be aging in general, but I still think the belted styles kept women smaller. Am I right?

A. There is no evidence that the physical effect of wearing a belt influences waist circumference. At best, wearing a belt is one way to keep tabs on your waistline. While having to loosen their belt a notch may drive some women to re-examine their diet and exercise routines, it doesn't sound as if you need to do that. I think your alternative explanation that aging is responsible is more likely to be true.

A combination of things happens as we age. We tend to lose muscle mass, so our abdominal muscles aren't as tight as they once were, and the loss of elastin and collagen in our skin allows gravity to have its way so skin starts to sag. Both can cause the waistline to expand. We also lose height as the discs between our vertebrae compress, shrinking the vertical space in our abdominal cavity and expanding it outward. Finally, the loss of estrogen after menopause causes a slight shift of fat to the abdominal region.

If it's any consolation, women whose waist measurements are 28 inches or less are at the lowest risk for heart disease, and you are still within that range. By keeping your weight stable, you've already reduced your risk for diabetes and certain cancers.

— Anne Fabiny, MD
Editor in Chief, Harvard Women's Health Watch
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