It sounds too good to be true. Lose 100 calories a day by eating?
But that’s the upshot of a study out of Tufts University, which found that people who eat whole-grain foods in the amount recommended for their daily allowance for fiber lost as many calories each day as they would burn in a vigorous walk.
“We provided all food to ensure that the composition of the diets differed only in grain source. The extra calories lost by those who ate whole grains was equivalent of a brisk 30-minute walk -- or enjoying an extra small cookie every day in terms of its impact,” said senior author Susan B. Roberts, Ph.D., senior scientist and director of the Energy Metabolism Laboratory at Tufts.
The researchers believe that whole grains help speed up metabolism and cut the calories your body absorbs during digestion.
What are whole grains?
Whole grains retain their nutritious outer layer of bran and the germ, which sprouts new plants. Milled, or refined, grains are processed to a finer texture and no longer contain the bran and germ. Think of the difference between white rice and whole-grain brown rice.
Some examples of whole grains are:
- Wild rice
- Fresh corn (avoid “degerminated” varieties)
- Whole-grain rye breads or other products
- Whole wheat
The Oldways Whole Grain Council lists a variety of whole grain choices, including tips on what to look for when you’re buying food.
The Providence Health Library describes how many Americans fail to include whole-grain foods in their diets, and gives ideas about how to find the best sources of whole grains. Hint: Read the nutrition labels on the foods you buy. Also see our Tips for Heart-Healthy Eating, which will fill you in on the importance of fiber in your diet.
Another benefit of whole grains
The Tufts study was published in The American Journal of Clinical Nutrition along with a companion study that looked at the role of whole grain foods on gut microbes. That study found a modest positive effect on healthy gut microbes and immune system responses.
The 2015-2020 Dietary Guidelines for Americans calls for women to eat at least 3 ounces of whole grains each day and men to eat 4. This is the equivalent of 1½ to 2 cups of brown rice or oatmeal each day.
The dietary guidelines include a helpful table showing the calories and fiber in a variety of foods, from high-fiber bran to roasted peanuts.