Men who increase their intake of whole-grain foods appear to have a hedge against weight gain, according to a study published in the November 2004 issue of The American Journal of Clinical Nutrition. The surprise in this study was that the mechanism of action was not the high fiber content of the whole grains.
“This suggests that additional components in whole grains may contribute to favorable metabolic alterations that may reduce long-term weight gain,” the researchers reported.
The study involved a prospective cohort of 27,082 men aged 40–75 in 1986. Researchers followed these subjects for 8 years, tracking their weight gain. At the end of this time, the researchers reported a dose-response relationship between whole-grain intake and long-term weight gain. For every daily 40-gram (g) intake of whole grains (derived from all foods), weight gain was reduced by 0.49 kilogram (kg). Bran added to the diet or obtained from fortified foods further reduced the risk of weight gain. No distinctions in terms of weight gain were noted between natural and refined whole grains.