An article on weight gain during and after menopause in Environmental Nutrition (April 2011, vol. 34, no. 4) caught my attention because it contains important—and surprising—information for all women, whether they’ve reached menopause or not.

The article states that “The transition through menopause is typically burdened with significant weight gain—about 1.5 pounds per year during the middle years, regardless of initial age, initial body size, or ethnicity, according to data from the Study of Women’s Health Across the Nation (SWAN), a multi-ethnic, community-based, longitudinal study of more than 3,000 women. However, there is broad debate among scientists over why and how this weight gain occurs.” According to one researcher, fat cells are protective because they produce estrogen. As it declines in a woman’s body, fat cells take over the process of helping her get through what may be a difficult transition. Another researcher challenges this conclusion by saying that the estrogen produced by fat cells is less potent than that produced by ovaries and that there’s no evidence that postmenopausal energy actually does help during this transition.

And then there’s the change in the female body shape—the “loss of muscle mass and a shift in body fat distribution to the abdomen”—even if weight remains the same. Scientists aren’t sure why this shift occurs (but I’m here to tell you that it does!), positing that it may be due to “loss of skin elasticity and muscle tone, characteristic signs of aging.” Another possible cause is that declining estrogen means a greater balance of testosterone, pointing to women, like men, putting weight on in the abdominal region.

A surprising conclusion about what we think of as inevitable post-menopausal weight gain: “As women age, if they exercise less and lose body muscle mass, their calorie needs decline.” A Massachusetts Women’s Health Study published in 2000 in Menopause led researchers to conclude that menopause transition is not consistently associated with increased weight; behavioral factors—particularly exercise and alcohol consumption—were more strongly related to weight than simply the transition through menopause. Moreover, study researchers insist “that aging—a period during which people tend to exercise less yet maintain the same amount of food intake—is likely responsible for the weight gain during middle age rather than menopause itself.”

My advice during menopause is to focus on health and fitness, and work on accepting your changing, aging body. Hard work, yes. But it beats the alternative.