Glycemic response and health: summary of a workshop

Interest in the glycemic impact of diet on health and well-being is growing among health care professionals and consumers. Diets with high glycemic impact have been postulated to increase risk of obesity, insulin resistance, diabetes, and cardiovascular disease. A reduction in the glycemic impact of the diet has been proposed as a means of assisting body weight management, improving blood glucose control, and reducing diabetic, cardiovascular, and related risks. Foods are increasingly carrying labels that describe their glycemic properties. Yet, a scientific debate exists about whether a relation between the glycemic response to diet and health truly exists, and, if so, which descriptor of a food's glycemic properties best predicts its effect on health outcomes. This article reports the proceedings of a workshop at which a meta-analysis of the relation between the glycemic response to foods and health was presented and the merits of glycemic index (GI), glycemic load (GL), and glycemic glucose equivalent as predictors of health outcomes were discussed. The conclusions include the findings that many studies purporting to investigate lower GI interventions actually studied lower GL interventions; that unavailable carbohydrate (eg, dietary fiber), independent of GI, seems to have at least as big an effect on health outcome as GI itself; that lower GI and GL diets are beneficial for health in persons with impaired glucose metabolism, but that it is as yet unclear what they mean for healthy persons; and that the larger the divergence of glucose metabolism from the norm, the larger the effect of lower GI and GL interventions.