A new study from researchers at Tufts University suggests that a simple switch in diet from refined grains to whole grains could lead to big results for dieters.

Results showed that consuming whole grains reduced calories retained during digestion and sped up metabolism when compared to the refined variety, according to a press release from Tufts.

Read: Eat Fiber: Whole Grains Prevent Gut Microbes From Eating Intestine Lining, Increasing Infection Risk

Researchers carried out an eight-week comparative study that included 81 men and women between the ages of 40 and 65. For two weeks prior to the study, they all ate the same foods and the research team determined individual calorie requirements. From there, participants were randomly assigned to follow either a whole grain or refined grain diet for eight weeks.

While on this diet, researchers tracked participants’ weight, metabolic rate, blood glucose, fecal calories, hunger and fullness for eight weeks.

Results showed that those who followed the whole grain regimen experienced an increase in resting metabolic rate, as well as fecal energy losses, compared to refined grain dieters. According to the press release, the latter was an effect the fiber had on the digestibility of other food calories.

These study results and previous research has confirmed that calorie loss was not because of the digestion of extra fiber intake.

Read: Cereals Rich In Whole Grains And Fiber Can Lower Risk For Early Death

"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., according to the release.

Source: Roberts SB, Karl JP, Meydani M, Junaidah BB, Vanegas SM, Goldin B, et al. Substituting whole grains for refined grains in 6-week randomized trial favorably affects energy balance parameters in healthy men and post-menopausal women. American Journal of Clinical Nutrition. 2017.

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