Like many women her age, my twenty-something daughter is not afraid to show off her midsection; she’s comfortable in low-slung jeans, bikinis, hip-hugging shorts, whatever. Sometimes I look at her and think, “Was my stomach ever that flat?”

But I know the answer. Yes, in fact, it was. I have photographic evidence. So what causes the midsection migration of fat as we age? Aside from the inevitable changes caused by the push and pull of past pregnancies, researchers are beginning to point a finger at hormones—but it’s not the one you might think. And this affects all women, including those who have never been pregnant.

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Why Metabolism Slows Down With Age

As we become “women of a certain age,” physical changes are inevitable: the never-before aches and uncooperative joints, maybe a bit of thinning hair and thinning skin, more root canals and crowns, a cataract or two. Most of those changes can be treated or covered up, if that’s what you desire. But possibly the hardest to accept and the most difficult to change is the shift in body type from pear to apple. In other words, most of us are likely to develop extra fat around the middle that didn’t exist until, like—just now. And many of us worry that once it develops, our destiny is elastic-waist pants and tunic tops. Forever.

As we get older, our bodies no longer need as many calories to stay stoked. We’re not building bone and muscle the way we used to.

So what exactly is going on? In truth, at midlife, we do shift into the metabolic slow lane. The metabolism is basically the chemical processes that occur to sustain life. As we get older, our bodies no longer need as many calories to stay stoked. We’re not building bone and muscle the way we used to.

Researchers long ago established that metabolism slows as we age, about 2 percent or so per decade. That may not sound like much, but it adds up over the years. Eat the same amount at 50 that you did at 20 and weight gain is inevitable, especially around your middle. That’s one factor we must all reconcile ourselves with.

The Three Little Letters Behind Your Belly

But the latest research says it’s not just age and it’s not a drop in estrogen (the usual suspect!) that is responsible for the ill-favored fat. Rather, it’s a surge in follicle-stimulating hormone (FSH). Any woman who’s gone through infertility, polycystic ovary disease, or any malfunction of the reproductive system is likely familiar with FSH. It’s a vital hormone that plays just as important a role after menopause as it did when you were in your 20s and 30s, but for different reasons. In your childbearing years, it nudged your ovaries to release an egg every month. As menopause approaches and estrogen begins its downward spiral, FSH increases. In fact, a blood test for FSH is often used to let you know that peri-menopause has arrived and menopause is waiting in the wings.

Now researchers are finding out that as you age, fat cells become more welcoming toward FSH. As this hormone surges, it causes fat cells in the abdomen to enlarge and voila!—belly fat is born. What’s more, researchers from Mount Sinai School of Medicine in New York have suggested that FSH may be responsible not only for the layer of unwelcome abdominal fat, but also for some of the bone loss that occurs with menopause.

As FSH surges, it causes fat cells in the abdomen to enlarge and poof!—belly fat is born.

There is one major caveat, however. Their findings come from a study with mice. The researchers took female mice whose ovaries had been removed and blocked FSH production using a designer antibody. The result? The mice actually lost large amounts of fat and the loss of bone was slowed. The researchers were shocked. It was a “weird, weird” finding, in their words. Suspecting it was a random result, they obtained a research grant, did it again, and got the same results.

The goal now is to test an anti-FSH antibody in people. If you think a drug like this would be for vanity’s sake, think again. Increased fat around the middle is linked with increased inflammation and an increased risk for cardiovascular disease, type 2 diabetes, colorectal cancer, and high blood pressure. It’s no picnic, but don’t hold your breath waiting for a miracle drug. Even if the findings in women safely confirm the findings in rats, it would likely be years and years before such a medication would be available.

What You Can Do Today

Despite what you may hear about chromium, ketones, cinnamon and apple-cider vinegar boosting metabolism, don’t waste your time or money. While some of these might have a small effect, no research has shown them to significantly boost metabolism or get rid of belly fat.

So what can you do in the meantime to shift the odds in your favor? Let me hit the highlights:

• While studies suggest that exercise per se doesn’t seem to make much difference in weight, working to maintain muscle, which naturally slips away as you age, can help increase calorie-burning. So yes, get active; more active than you’ve been.
• Reducing stress is another great move. Not only will it soothe your spirit, but it may also give your metabolism a jump-start. Here’s why: Stress triggers the release of another hormone, cortisol, which can stimulate the laying down of fat.
• Get plenty of sleep. Not only is lack of shut-eye stressful (see above), it can create a gnawing hunger that isn’t easily satisfied. And mindless eating—especially at 3 a.m.—is not a good way to ward off weight.

But when all is said and done, belly fat is also due to your DNA. So, instead of blaming yourself for all those years of taking your body for granted or for your current lack of willpower, blame your mother. That always works.

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