Everyone has a body part that seemingly collects every calorie they’ve ever eaten, ever. For men, it’s usually their gut, while for women, it tends to be their hips and thighs. But is there any rhyme or reason behind why our fat goes where it goes? Liz Weinandy, resident dietitian at The Ohio State University Wexner Medical Center, says that while women’s so-called sex-specific fat has physiological advantages, men aren’t so lucky.
“Women store fat around their hips and thighs as a source of post-pregnancy fuel,” Weinandy explains. “Once a woman has a baby, that fat supplies her with the energy she needs to breastfeed the child.” This storage process begins at a young age for most girls: During the adolescent growth spurt, the rate of fat increase in girls almost doubles that of boys. That’s a result of an increase in the female sex hormone estrogen, which promotes the growth of fat cells around the hips, thighs and butt.
High levels of estrogen also make it more difficult to shed fat from the hips-thighs-butt region than from other areas of the body—until they start breastfeeding, that is. During the lactation period, the fat around a woman’s hips and thighs essentially (and in not very scientific terms) migrates to her breasts to provide fuel in the form of milk. Fat distribution shifts for women during their 40s and 50s: “When a woman goes through menopause [a natural decline in reproductive hormones], her estrogen levels drop, and as a result, she starts storing weight around her abdomen,” Weinandy explains.
That lack of estrogen is the very same reason men store weight around their stomachs, rather than their hips and thighs. Unlike women, however, a man’s potbelly serves no good purpose—in fact, it’s downright dangerous. “Fat stored around the abdomen is called visceral fat, meaning it’s stored around important organs like the liver, pancreas and intestines,” Weinandy explains. “Too much of this fat can cause complications like heart disease, diabetes and fatty liver disease, which is on the rise.” Worse yet, a bulging belly can cause a forward shift in the body’s center of gravity, which can lead to severe back pain.
Studies also show that a man is more likely to grow a potbelly with age, as his testosterone (aka, the male sex hormone) levels start to deplete. It’s also been shown that stress-induced cortisol—a steroid hormone similar to testosterone—promotes fat storage around the stomach, meaning too many long, hard days at the office could contribute to the fact that you can’t see your toes.
Those work days—especially if you’re in a desk job—can also contribute to the fact that your once-voluptuous tush is now flat as a board. That’s because years of sitting can cause what’s called an anterior pelvic tilt, which is when your pelvis essentially tilts forward and makes your butt look flatter than it really is. Add that to the fact that men lose an average of five percent of muscle mass (muscle that once kept your rump perky) every 10 years after the age of 35, and you can say sayonara to filling out your favorite jeans.
The good news is, even though your hormones seemingly want you to become a jiggling ball of fat, if you continue to eat right-ish and follow what we think of as a normal person’s workout guide, it is actually possible to avoid it.