Researchers suggest switching to whole-grain foods may actually help you lose weight. Based on previous research and current study measurements, however, they believe that the calorie loss was not due exclusively to the digestion of extra fiber intake.
The nutritionist said that this new study has helped them to "quantify how whole grains and fiber work to benefit weight management", while also giving credibility to the previous reports that have suggested that increasing one's consumption will in fact lead to better overall health, as well as lowering one's body weight. Both studies are published online today in the American Journal of Clinical Nutrition.
To make this finding, Tufts researchers provided 81 men and women aged between 40 to 65 all their daily food for eight weeks. These men and women were asked to consume the same food during the first couple of weeks, and were then divided into those who were provided with a diet of whole grain foods and those who were given the refined-grain diet.
Although improvements were modest, the results showed that those who ate the whole grain diet had an increase in Lachnospira, the bacteria that produces short-chain fatty acids, and a decrease in the pro-inflammatory bacteria, Enterbacteriaceae.
Throughout the eight weeks, researchers measured weight, metabolic rate, blood glucose, fecal calories, hunger and fullness.
Whole grains increased the rate of metabolism and promotes weight loss.
In the first two weeks, all the participants ate the same type of food and individual calorie needs were determined.
Furthermore, the extra fecal energy loss was the result of the effects of the fibre content on the digestion of calories from other foods, and not because of the extra fibre itself.
'The extra calories lost by those who ate whole grains was equivalent of a brisk 30 minutes walk? or enjoying an extra small cookie every day in terms of its impact'.
The researchers add that these beneficial effects were only generated because of a close adherence to the particular diet, and so, they include a word of caution regarding the interpretation of their findings. This is compared to those who consumed refined grains without a lot of fiber. Whole grain flour and whole grain kernels were the ideal diet that should be followed.
The grain group includes foods such as rice, wheat, oats, and barley. A whole grain contains all three components, whereas a refined grain is processed so that the bran and germ are removed.
The research compared people eating whole grains such as whole-wheat flour, oatmeal and brown rice with people eating refined grains such as white flour, white bread and white rice. This process, known as milling, drains the starch of dietary fiber, iron and many forms of B vitamin. But one thing to keep in mind before you start filling your grocery cart with "whole grain" products is labels can be misleading.