Aside from being known to help in glycemic control and insulin sensitivity, whole grains and high dietary fibers have also been proved to have beneficial effects in weight regulation.

According to a new study published in the American Journal of Clinical Nutrition, eating whole grains and high dietary fiber has the same calorie reducing effect as brisk walking for 30 minutes.

"This study helps to quantify how whole grains and fiber work to benefit weight management, and lend credibility to previously reported associations between increased whole grains and fiber consumption, lower body weight and better health," said Phil J. Karl, PhD, a nutrition scientist t the U.S. Army Research Institute of Environmental Medicine and first author of the study, in a press release.

For the study, the researchers controlled the diet of 81 men and women between the ages of 40 and 65 for eight weeks. During the first two weeks, all the participants in the study ate the same type of food. During this time, the researchers determined the individual calorie needs of each participants.

After the initial two weeks, the researchers divided the participants into two groups. The first group was given a diet that included whole grains, while the second group was given a diet of refined grains. The participants were asked to consume only foods given by the researchers and carry on with their usual physical activities.

The whole grain and refined grain diet only differ in grain and fiber content. The researchers made sure that type of food, energy, meal structure and macronutrient composition is similar in both groups. During the course of the eight-week study, the researchers measured the weight, metabolic rate, blood glucose, fecal calories, hunger and fullness of each participant.

The researchers observed that participants in the whole grain group have an increase in resting metabolic rate and fecal calorie loss, compared to those who were given a refined grain diet. By reducing the calories retained during digestion and speeding up metabolism, the whole grain diet was able to increase calorie loss.

Despite the results of the study, the researchers noted that the effects of the whole grain diet on resting metabolic rate rely deeply on dietary adherence. The recommended minimum daily allowance of whole grains for women is three ounces, while men are advised to consume a minimum of four ounces of whole grain.