A foods glycemic index is determined by the speed at which glucose, or sugar, enters the blood stream. Foods with a high glycemic index rapidly increase one's blood sugar and include white bread, table sugar, and bananas. Foods with a low glycemic index usually take longer to digest and slowly increase the blood sugar and include brown rice, leafy greens, and apples.
The glycemic index of foods can effect the development of diabetes and metabolic syndrome, two conditions characterized by blood sugar dysregulation. But some people believe the glycemic index of foods also affects weight gain. To test this hypothesis researchers in Denmark studied the diet of nearly 400 men and women over a six year period.
Each of the participants were of normal weight. Dietary habits were assessed at two different times six years apart. The researchers were mainly gathering data on the types of food choices the participants made in regards to the glycemic index. They also assessed weight gain and distribution over the six year period.
The results were published in the October issue of The American Journal of Clinical Nutrition.
Women in the study who consumed a diet with a majority of high glycemic index foods were more likely to add weight over the six year period compared to women who ate foods low on the glycemic scale. Weight gain in men was unaffected by the glycemic index of food choices.
In particular women who gained more weight had greater change in waist circumference and percentage of body fat as well as the increase in overall weight. A gradual increase in waist circumference is associated with Metabolic Syndrome in some studies and also may increase the risk for developing Type 2 diabetes in some studies.
The authors caution that this study was small and do not recommend that women go out and switch to a low glycemic index diet for weight loss, though the diet has other positive effects. More trials are needed to prove a true effect of foods glycemic index on weight gain.
Posted by Dr. Christina Gutierrez on November 2, 2006 01:49 PM
