Problem

Your Hormones Fluctuate
Over the decades, women’s bodies produce less of certain hormones — particularly estrogen, which typically starts ebbing in the 40s. It’s at that time, during the run-up to menopause rather than during menopause itself (which occurs on average at age 51), that sinking estrogen levels cause the most weight gain. Since estrogen has appetite-regulating properties, many women experience cravings or find themselves hungrier than usual as their hormone levels drop, says Jennifer Lovejoy, Ph.D., dean of the School of Nutrition and Exercise Science at Bastyr University, in Kenmore, Washington.

Estrogen also affects how the fat in your body is distributed. As levels of the hormone decline, body fat tends to migrate from the hips and the thighs to the waist. Abdominal fat not only is more likely to cause health problems, such as heart disease and diabetes, but is also harder to shed than fat in other places. “Even if you control your weight and work out,” says Lovejoy, “there’s really not much you can do about the fact that your waist is going to expand a little bit.”

Other hormones factor in, too. Starting in their 40s, women (and men) experience a dramatic drop in levels of human growth hormone. One role of this hormone is to break down fat, preventing its storage around the belly. So as the hormone becomes scarce, a potbelly may become more noticeable.

Belly fat also accumulates in response to stress. Cortisol, a fight-or-flight hormone that is secreted in tense situations, channels fat to the midsection and intensifies cravings for high-fat foods — a double whammy for those who reach for French fries when under pressure. This can happen quite often, given the amount of angst that many women live with, juggling work and home, young children and aging parents. “If you’re someone who is susceptible to stress and high cortisol levels, it’s probably going to leave you with more of an apple shape,” says Elissa Epel, Ph.D., a psychologist at the University of California, San Francisco.

Solution

Eat Well and Reduce Stress
Alas, there is not much that you can do to prevent hormonally induced shape shifting. There’s no evidence that hormone-replacement therapy helps. A sensible diet and a substantial exercise regimen can minimize the spread, as can reducing stress (and cortisol levels) by relaxing, getting enough sleep, exercising, and finding other ways to stay calm.