Some diets don’t seem to make a dent in that stubborn muffin top. But now experts say consuming fiber—the right kind in generous amounts—may be the path to a leaner waistline, better health, and resistance to diseases.
Excess belly fat is not only unattractive; it could be deadly. Visceral fat hides deep in the core, nestled around organs. Different from the jiggly, just-skin-deep fat that determines whether you look good in skinny jeans, deep fat is dangerous. It releases inflammatory compounds that increase a person’s risk of developing cardiovascular disease, cancer, and diabetes. As if that triple threat weren’t enough, a 2009 study from Rush University Medical Center indicates that these compounds are also triggers for depression. What’s more, a 2010 study by Harvard Medical School radiologists indicates that active excess visceral belly fat is linked to bone loss and the development of osteoporosis.
According to Charlotte Lawson, RD, LD, a public health dietitian based in Florida, “A small amount of belly fat does not pose any real harm, but excess amounts around the middle can release more fat into the bloodstream after a meal. This can lead to increased triglycerides and free fatty acids, which can ultimately cause insulin resistance.” Belly fat, she adds, can also release enzymes that increase stress hormones such as cortisol, which make it generally harder to lose weight.
Researchers have long contemplated what makes genetics, diet, and exercise the keys to eliminating obesity. A team that included Kristen Gill Hairston, MD, an assistant professor of internal medicine at Wake Forest School of Medicine in Winston-Salem, North Carolina, conducted a study of 1,114 men and women, measuring deep fat with imaging—CT scans or MRIs. The study, says Hairston, shows how soluble fiber may affect the accumulation of visceral belly fat. For every 10 grams of soluble fiber that participants added to their diets each day, visceral fat was reduced by 3.7% over five years.
“Eating 10 grams of fiber is achieved by consuming two small apples, 1 cup of green peas, and 1⁄2 cup of pinto beans in a day,” explains Hairston. Great sources of soluble fiber also include other types of beans, oats, citrus fruits, and barley.
The study also points to the importance of exercise for reducing belly fat. Moderate activity—exercising for 30 minutes two to four times a week—results in a 7.4% decrease in the rate of visceral fat accumulation.
Obviously, we can’t each get a CT scan to measure our midsection. But those skinny jeans that haven’t fit for years may provide a clue. “Some visceral fat is normal, but detrimental levels of visceral fat are usually only seen when a person is overweight in general,” Hairston says.
“Women should aim for a waist circumference under 35 inches,” Lawson says, “and men less than 40 inches to reduce their risk for diabetes and heart disease.”
Hairston’s results revealed a tendency for blacks and Hispanics to have higher rates of visceral fat.
And many Americans have sported a super-sized waistline for a while. But Hairston offers hope. “Make small changes in the areas that you can affect,” she says. “We cannot change our race or gender or ancestry, but we can change what we put in our mouths and what we do with our bodies.” Her three-fold prescription includes “increasing fiber, getting six to seven hours of sleep each night,and exercising.”