Weight was never a concern for Stephanie Brondani, 52, of Minnetonka, Minn. That is until last year, when she hit menopause.
Suddenly, she noticed her midsection thickening. "I think everybody feels (like), 'I'm eating the same way I always have been and yet I'm getting this roll.' What is that about?" she said.
Scientists have long known that lower estrogen levels after menopause can cause fat storage to shift from the hips and thighs to the abdomen. Now, a groundbreaking study, co-authored by the Mayo Clinic, has determined why: Proteins, revved up by the estrogen drop, cause fat cells to store more fat. And it gets worse: These cellular changes also slow down fat burning by the body.
Even though the research doesn't provide weight-loss solutions, it may bring a sense of relief to millions of middle-aged women who have been fighting an often losing battle against the dreaded "post-meno belly."
"It doesn't mean you're absolutely doomed," said Dr. Michael Jensen, an endocrinologist at the Mayo Clinic and one of the study's authors, "but it does mean it's going to be harder, probably" to lose weight.
That comes as welcome news to Brondani, who has tried a new exercise program, wears a pedometer and has cut back on sugar and junk food.
"There's that sense of 'Oh, this is just normal,'" she said. "While you don't have to just lay down and take it, you know you're not doing anything wrong. At least you feel like it's OK, everybody is going through this. Not just me."
More than 50 million U.S. women are 50 or older; 75 percent of women ages 50-55 are postmenopausal, according to the Menopause Center of Minnesota. Most -- if not all -- will confront postmenopausal weight gain.
According to a 2010 study in the International Journal of Obesity, women gain an average of 12 pounds within eight years of menopause. But even women who maintain the same weight say they notice their waistline expanding.
Cassandra Clay-Chapman started putting on pounds soon after she entered menopause a few years ago. Before she knew it, she was 10 pounds heavier.
"It just happens," she said. "You just blow up like a balloon."
Clay-Chapman, who now lives in Scottsdale, Ariz., is one of 24 women who participated in the Mayo study, the results of which were published recently. The group included Minnesota women who were both premenopausal and postmenopausal. They were all about the same age -- 49 to 50 -- and had the same body fat levels, Jensen said.
But beyond vanity concerns, there are health risks associated with having an extra layer of padding around the waist.
Belly fat is a sign of visceral fat around vital organs and increases a person's risk for obesity-related illness. According to the Mayo Clinic, a waist measurement of 35 inches or more can lead to a greater risk of problems such as heart disease, high blood pressure and diabetes.
The Mayo research might lead to strategies for maintaining a healthy weight after menopause. For example, Jensen said it raises questions about the kinds of dietary changes doctors might suggest. It also raises questions about whether hormone replacement therapy may play a role in offsetting weight gain.
Sylvia Santosa, an assistant professor of nutrition science at Concordia University in Montreal, Quebec, and the study's co-author, added that while science doesn't offer any fixes for the post-meno belly, the findings shed much-needed light on the issue. "It puts us one more step toward understanding how estrogen affects how and where we store fat," she said.