Eat more grains, burn more calories

By Providence Health Team

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 fiber allowance lost as many calories each day as they would burn in a vigorous walk.

“We provided all food to ensure that the composition of diets differed only in grain source,” said senior author Susan B. Roberts, PH.D., senior scientist and director of the Energy Metabolism Laboratory at Tufts. “The extra calories lost by those who ate whole grains was equivalent to a brisk 30-minute walk, or enjoying an extra small cookie every day in terms of its impact.”

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:

  • Quinoa
  • Wild rice
  • Fresh corn (avoid “degerminated” varieties)
  • Whole-grain rye breads or other products
  • Whole wheat
  • Oats
  • Barley

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 nutritional 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: a healthier gut

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. The latter study found a modest positive effect on healthy gut microbes and immune system responses.

How much should we eat?

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 daily.

The dietary guidelines include a helpful table, which shows the calories and fiber in a variety of foods – from high-fiber bran, to roasted peanuts.