Though at first they may seem too “heavy” to be a diet food, whole grains have been proven to help with weight control.
A study conducted by the Harvard School of Public Health showed that eating 40 grams (equivalent to about 1 cup of oatmeal or 3/4 cup of brown rice) of whole grains a day could significantly reduce middle-age weight gain. It’s thought that the fiber and protein in whole grains helps to regulate blood sugar, increase satiety and delay the return of hunger. The body also uses more calories to break down high-fiber foods.
Remember though, it's getting the right number of calories that leads to weight loss - not specific foods.