The study looked at the eating habits — including the consumption of whole-grain bread, brown rice, popcorn and other whole grains as well as fruits and vegetables — of 177 men and 257 women, who averaged 68 years old.
Overall, the participants consumed relatively low amounts of whole-grain foods, averaging 1.5 servings a day, and dietary fiber, averaging 18.6 grams a day. U.S. Department of Agriculture dietary guidelines recommend that older people consume three or more servings daily of whole-grain foods and 21 to 30 grams of dietary fiber a day.
Among the study participants, bread and cold breakfast cereals were the main sources of whole grains, and women were more likely than men to consume whole grains.
After adjusting for factors such as levels of physical activity, the researchers found that a higher intake of whole grains was associated with lower amounts of total body fat and abdominal fat.
People who consumed the highest amounts of whole grains had about 2.4 percent less total body fat and 3.6 percent less abdominal fat than those who ate the least. This difference was found to be related to fiber in cereal, but not in fruits or vegetables. When only cereal fiber was taken into account, those who consumed the most had 3.2 percent less body fat and 5 percent less abdominal fat than those who ate the least amount of cereal fiber.
The findings appear in the October issue of the Journal of Nutrition.
The study’s authors said that further research is needed to learn more about how whole-grain foods might regulate energy intake and how different types of fiber affect body fat distribution.