People who eat fiber, which is found in whole grain foods, consume fewer calories and boost their metabolism. And that can help keep your weight i check as effectively as a brisk 30-minute daily walk, according to research from Tufts University in Boston. What are whole grain foods? They include barley, brown rice, wild rice, buckwheat, cracked wheat bulgur, millet, oatmeal, popcorn and whole wheat bread, pasta and crackers How do whole grain foods keep your weight in check? Study leader J. Phili Karl, a nutrition scientist, explains that whole grains seem to do double duty: First, they lower the number of calories your body absorbs during digestion and they speed metabolism. What the study did not prove is whether a whole grain diet will result in weight loss, but Karl suspects that it will — specifically five pounds a year.