IS YOUR BIG BELLY SLOWING YOU DOWN?

Whole Grains Battle Your Dangerous Belly Fat

American Journal of Clinical Nutrition, November 2010

Whole grains can help fight the belly fat that’s linked to heart disease and diabetes, according to Tufts researchers, while refined grains like white bread and pasta can cancel out those benefits.

“Observational studies have linked higher intakes of whole grains to lower abdominal adiposity; however, the association between whole- and refined- grain intake and body fat compartments has yet to be reported,” noted Nicola McKeown, PhD, a scientist in Tufts’ HNRCA Nutritional Epidemiology Program and program director of Nutrition Epidemiology at the Friedman School, and colleagues in the American Journal of Clinical Nutrition.

So McKeown and colleagues analyzed data on 2,834 men and women, ages 32 to 83, participating in the renowned Farmingham Heart Study.  Dietary information was assessed using a food-frequency questionnaire, and results were adjusted for other lifestyle factors such as smoking and alcohol consumption, as well as calorie intake.  Researchers compared grain intake with individuals’ abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) -essentially, belly fat.  Such fat around the abdominal organs is particularly unhealthy, and is a factor in metabolic syndrome, a precursor to heart disease and diabetes.

People who reported eating three or more daily servings of whole grains and who limited their intake of refined grains to less than one serving a day averaged 10% lower VAT volume.  Eating more whole grains was also associated with lower SAT, while people consuming more refined grains tended to have greater SAT volumes.

In this study, a serving of whole grains was considered one cup of whole-grain breakfast cereal, such as oat cereal; half a cup of cooked oatmeal, brown rice or other grains; one slice of dark bread; three cups of popcorn; or two tablespoons of added bran or added germ, such as wheat germ.  Refined grains included processed breakfast cereals, white bread, English muffins, bagels, muffins, biscuits, white rice, pasta, pancakes, waffles, crackers, and pizza.

McKeown and colleagues reported that the VAT-fighting benefits of whole grains were diminished among people also eating four or more daily servings of refined grains.  McKeown commented, “This result implies that it is important to make substitutions in the diet, rather than simply adding whole-grain foods.”

How much whole grains should you aim to include in your diet?  The American Heart Association recommends getting at least three one-ounce-equivalent servings of fiber-rich whole grains per day.