Whole Grain Diet Linked to Lower Body Fat

Eating several servings of whole grains per day while limiting daily intake of refined grains appear to create less fat tissue in the body, according to researchers.

They add that limiting this particular type of fat tissue may help prevent cardiovascular disease and type 2 diabetes.

What's the difference between "whole" grain and "refined" grain? As the name implies, there is more of the grain in whole grain. It contains germ, endosperm and bran. Refined grain, on the other hand, usually just retains the endosperm.

Whole grains are a natural source of protein, as well as a source of carbohydrates.

Researchers at the Jean Mayer USDA Human Nutrition Researcher Center on Aging (USDA HNRCA) at Tufts University observed lower volumes of visceral adipose tissue (VAT) in people who chose to eat mostly whole grains instead of refined grains.

Whole grains three times a day

"VAT volume was approximately 10 percent lower in adults who reported eating three or more daily servings of whole grains and who limited their intake of refined grains to less than one serving per day," said first author Nicola McKeown, PhD, a scientist with the Nutritional Epidemiology Program at the USDA HNRCA.

An example of whole grain food is oatmeal or whole wheat bread. Examples of refined grain food are rice and white bread.

McKeown and colleagues, including senior author Caroline S. Fox, MD, MPH, medical officer at The Framingham Heart Study of the National Heart Lung and Blood Institute (NHLBI), examined diet questionnaires submitted by 2,834 men and women enrolled in The Framingham Heart Offspring and Third Generation study cohorts.

The participants, ages 32 to 83, underwent sophisticated tests to determine VAT and subcutaneous adipose tissue (SAT) volumes.

Visceral fat surrounds the intra-abdominal organs while subcutaneous fat is found just beneath the skin.

"Prior research suggests visceral fat is more closely tied to the development of metabolic syndrome, a cluster of risk factors including hypertension, unhealthy cholesterol levels and insulin resistance that can develop into cardiovascular disease or type 2 diabetes," said co-author Paul Jacques, director of the Nutritional Epidemiology Program at the USDA HNRCA and a professor at the Friedman School of Nutrition Science and Policy at Tufts.

"Not surprisingly, when we compared the relationship of both visceral fat tissue and subcutaneous fat tissue to whole and refined grain intake, we saw a more striking association with visceral fat. The association persisted after we accounted for other lifestyle factors such as smoking, alcohol intake, fruit and vegetable intake, percentage of calories from fat and physical activity," Jacques said.

Read the labels

Adding whole grain foods to your diet will probably require some label-reading. When shopping, check the ingredients list closely. If the first ingredient in the list is "whole wheat," "whole meal," or whole corn," then it's a whole grain food item.

Try to avoid products with ingredients described as "enriched" or "bromated." That could indicated refined ingredients.

Just because the first ingredient is listed as "wheat flour," that doesn't necessarily mean it's a whole grain product. A better indicator is "wholegrain wheat flour" or "whole wheat flour."