En español | A widening waistline is often the curse of middle age — and not just because it can be unsightly.
Those who store fat in their bellies are at higher risk of heart disease, stroke, diabetes and certain cancers.
And unfortunately, that's most of us. In the United States, more than 50 percent of men and 70 percent of women between ages 50 and 79 now have a condition as "abdominal obesity."
Your expanding middle carries two kinds of fat — subcutaneous fat you can see and pinch, and visceral fat, which surrounds the abdominal organs deep inside the body. Subcutaneous fat, which also is carried in the hips, thighs, arms and legs, may be unwanted, but it's not particularly dangerous.
Visceral, or belly, fat, on the other hand, is hazardous to your health. Numerous studies show a link between a large waist and a higher risk of death — even among people who aren't overweight. In fact, researchers now say your waist size, which generally reflects the amount of visceral fat you carry, may be a better predictor of disease than your BMI (body mass index).
"It's location, location, location that matters," in real estate, and that goes for fat, too, says Philipp Scherer, of the University of Texas Southwestern Medical Center in Dallas.
Until recently, scientists thought fat cells were simply storage units for excess calories. But researchers now consider visceral fat an active organ, like the liver or pancreas. "Our views of fat have changed over the last 15 years," says Scherer.
Visceral fat actually secretes hormones and lipids — such as triglycerides — that are harmful to the body, says David Cummings, M.D., professor of medicine at the University of Washington Medical School. It impairs the body's ability to use insulin, increasing the risk of type 2 diabetes. And it triggers the inflammation that can cause heart disease. Cummings says women's risk of heart disease rises after menopause to the level of men's because that's when women begin to accumulate belly fat.
There's also strong evidence visceral fat may cause colon cancer, according to the American Cancer Society. Moreover, this dangerous fat is associated with a higher risk of rectal, pancreatic, endometrial and postmenopausal breast cancer.
Recent studies also have linked belly fat to poor brain health.
So how do you lose belly fat? Experts say there is no magic formula, but it can be done, and it's not as difficult as you might think. When you use the classic combination of diet and exercise, visceral fat often goes away first.
Workout videos and glossy magazines promise that crunches, sit-ups and other abdominal exercises will banish belly fat. Not so, says Colleen Doyle, director of nutrition and physical activity for the American Cancer Society. These exercises will tone and strengthen abdominal muscles, but they won't melt away the fat. " You can't spot-reduce," says Doyle, who recommends finding a physical activity you enjoy and doing it regularly — whether it's walking, or playing tennis.
And a note to smokers: Beware of trying to control your appetite and weight through smoking. Swiss researchers have reported that smoking actually causes people to redistribute their weight to the belly area.
In the end, fewer calories and more exercise is what works, says Jo Ann Hattner, a nutrition consultant with Stanford University School of Medicine and coauthor of Help! My Underwear Is Shrinking!
"It's the prudent diet. It's more vegetables, more fruits, more whole grains," Hattner says. Emphasize healthy foods containing potassium, calcium, dietary fiber and vitamin D. Cut back on sugars — especially sugar-sweetened beverages — as well as saturated fats and refined grains such as those found in pastries.
"You have to understand that this is a lifelong change," she says. "This is not a diet in which you lose weight and then you can go back to your normal eating patterns. That just doesn't work."
Which diet is best?
One recent study suggests a low-carbohydrate diet may best target visceral fat. A Johns Hopkins University study of people with large bellies found that those who ate a healthy low-carb diet lost both more pounds and more belly fat than the group on a low-fat diet, says Kerry Stewart, director of exercise physiology at Johns Hopkins School of Medicine, the lead author of the study.
Cummings of the University of Washington, however, doesn't put too much stock in any one diet. "Go on whatever diet you think you can stick to," he suggests. Once you start losing weight, the payoff comes quickly. With every pound of belly fat that's lost, health risks diminish, too. Several studies have shown that you don't need to lose all the weight to get dramatic improvement. Scherer says even a weight loss of 5 to 10 percent lowers dangerous levels of insulin and estrogen.
Know your waist size
Only an MRI or a CT scan can show how much visceral fat you really have. But your waist size is a good indicator. The danger zone for women is a waist that's 35 inches or larger; for men it's 40 inches or larger. To measure correctly, wrap a measuring tape around your bare abdomen, just above the hip bone. Another way to take stock? Watch how your pants fit. Says Hattner: "The clothes really tell the truth."