Summer might be over, but don’t let your waistline go to the dogs just yet. Looking good at the beach isn’t the only reason to flatten our tummies. Recent studies in fat distribution are giving us an even more pressing incentive to reduce our rounding stomachs: our health.
It turns out that abdominal fat (more so than fat in other areas of the body) has a major impact on whether we stay healthy and vital or put ourselves at increased risk for several chronic diseases.
First off, we’re not talking about your typical tummy fat, so don’t fret about a little paunch. All of us need a bit of internal belly fat, says nutritional expert Pamela Peeke, MD, MPH. “We need stomach fat to help cushion organs, maintain internal body temperature, and it’s also a good source of backup fuel,” says Peeke, author of Body for Life for Women: A Woman’s Plan for Physical and Mental Transformation (Rodale, 2005) and Fight Fat After Forty (Penguin, 2000).
The problem is that not all abdominal fat is created equal . It is the type of belly fat—and the places it’s located—that determine whether it’s likely to lead to health problems.
Two Types of Fat
Ringing all our midsections are two different kinds of fat: subcutaneous and visceral. Subcutaneous, which means “under the skin,” is the fat we can see and pinch the jiggly stuff most of us lament in our bathroom mirrors. But, surprisingly, we need to worry less about subcutaneous fat than we do the visceral stuff.
Visceral, which means “pertaining to the soft organs in the abdomen,” is the fat stored deep in our abdomens around the intestines, kidneys, pancreas and liver. This is the stuff that tends to make our tummies protrude in classic “beer belly” fashion.
While visceral fat and subcutaneous fat look much the same from a surgeon’s point of view (they have the same consistency and yellowish color), they look different under a microscope, and they function very differently on a biological level.
Subcutaneous fat is often described as a “passive” fat because it functions primarily as a storage repository. It requires a fair bit of metabolic intervention from other body systems and glands in order to be processed for energy. Visceral fat, by contrast, is considered very “active” because it functions much like a gland itself. It is programmed to break down and release fatty acids and other hormonal substances that are then directly metabolized by the liver.
Carrying excess visceral fat “is like trying to pack seven to ten pounds of potatoes in a five-pound bag,” says Silver Spring, Md. based bariatric surgeon Gary C. Harrington, MD. “There’s no more room for things to grow in there, so it becomes very tight.”
So why is it that some of us tend to gain weight in our midsections? There is no single answer. Instead, the calculus behind the appearance of a potbelly involves four factors: genetics, eating habits, stress, and hormones.
The first part of the equation is the genetics of body shape. Some of us, says Savard, are just destined to be “apples,” with an inclination to gain weight in the stomach and upper-body region, while others are fated to be “pears,” who gain weight in their hips, buttocks, thighs, and lower legs. According to Savard, it all comes down to your waist-to-hip ratio (WHR), which is the division of your waist measurement by your hip measurement. (For an accurate WHR measurement, relax your abdomen and measure at the navel and around the bony part of the hips.)
If you’re a woman whose WHR is 0.80 or lower, you are pear shaped; if your WHR is higher than 0.80, you’re apple shaped. For men (who, for the most part, are apple shaped, since they are more inclined to store visceral fat), the cutoff is 0.90 instead of 0.80.
Many experts now agree that WHR is a better indicator than body mass index (BMI) when it comes to determining someone’s disease risk. Even apples who are currently slender and have a low BMI, Savard says, could be at increased risk for disease later in life.
“If you’re a string bean with no obvious potbelly, but your waist-to-hip ratio is more than 0.80, you will tend to have more health problems than pear-shaped people if you gain weight,” she says. When WHR is greater than 1.0 in men or 0.90 in women, health experts may diagnose the condition as “central obesity.”
Abdominal fat, like all fat, is produced when we ingest more caloric energy than our bodies can use. And our bodies were simply never designed to withstand such easy access to the kinds of calorie-dense foods available to us today.
“It’s certainly no secret that the way we eat is out of sync with our body’s needs,” writes Floyd H. Chilton, PhD, in Inflammation Nation: The First Clinically Proven Eating Plan to End Our Nation’s Secret Epidemic (Fireside, 2005). “Most of the evolutionary forces that shaped our genetic development were exerted over ten thousand years ago when we were hunter-gatherers. Nothing in that programming could have prepared us for the Big Mac. Our bodies, and more specifically our genetics, simply aren’t designed to eat the ‘foods of affluence’ available to a twentieth-century urban dweller.”
Visceral fat was simply never a problem years ago, says Savard. Take the Pima Indians of Arizona, she says, who have prototypically apple-shaped bodies. Because the Pima Indians evolved during alternating periods of feast and famine, they developed what researchers call a “thrifty gene,” which allowed them to store visceral fat during plentiful times and use it during lean times.
Living and eating as they did traditionally, subsisting on foods they hunted, gathered, or raised themselves, the Pima tended to be slender. Today, however, most are extremely overweight and suffer a 50 percent rate of diabetes among adults (95 percent of those people are overweight). “Now, with an unlimited supply of food and a more sedentary lifestyle,” says Savard, “the problem of visceral fat is not going away.”
Food today is not just more accessible, it has been reincarnated in so many heavily processed forms that we are often eating things that our bodies do not recognize as food. Our metabolism is still hardwired to process the hunter-gatherer diet of yore, and when it encounters sugary sodas and snacks that were created in a laboratory and not in a field, it is not able to process or use them efficiently. Instead, our bodies are forced to sock away that stored energy in places like our midsections where it does more harm than good.
Potbellies, also known as “beer bellies,” are often associated with drinking. But “beer does not promote weight or waist gain any more than any other source of calories,” says Meir Stampfer, MD, professor of nutrition and epidemiology at the Harvard School of Public Health. In fact, a 2003 study of 2,000 men and women from the Czech Republic, where people consume more beer per person than in any other country in the world, found no link between the amount of beer a person drinks and the size of his or her stomach. That said, alcoholic beverages are an often-overlooked, carb-dense source of calories in many people’s diets. Alcohol is processed much like a sugar in the body, and because it puts an additional strain on the liver, it may undermine the body’s fat-processing abilities.
Stress is another major reason some of us tend to pack on excess abdominal fat. As Peeke puts it, when it comes to weight gain, “genetics may load the gun, but environment pulls the trigger.” Peeke, who spent years researching the link between stress and fat at the National Institutes of Health, says that experiencing chronic stress is not only toxic for our bodies but can also beget an expansive waistline.
All of us may experience what Peeke terms “annoying but livable” stress like traffic jams and long lines at the supermarket, but chronic stress resulting from, say, a bad marriage, an illness, or career challenges can actually trigger our bodies to produce high levels of cortisol, which, among other things, gives us an intense appetite that causes us to overeat. Even worse, Peeke points out, the weight we gain as a result of sustained cortisol production tends to settle mainly in our abdomens.
Declining sex hormones is another key reason why both men and women start to develop a paunch as they age. Even pear-shaped women, whose body chemistry is mostly governed by estrogen, start to lose their estrogen advantage after menopause and are exposed to increased health risks, says Savard. “When they gain weight after menopause, the tendency is to put on visceral fat,” she says. And if they accumulate enough visceral fat, their body shape “can transform from pear into apple.”
Front and Center
While there is no quick-fix approach to losing abdominal fat, thinking holistically and making real lifestyle changes can go a long way toward shedding that stubborn belly.
Updated on December 18, 2010