The glycemic index issue
Purpose of the review In recent years, many of the concerns surrounding the glycemic index (GI) have been addressed by methodological studies and clinical trials comparing diets carefully matched for other nutrients. These findings are reviewed together with new observational evidence for the role of the dietary GI in the etiology of cardiovascular disease. Recent findings The determination and classification of the GI of a food product is now standardized by the International Standards Organisation. Systematic studies using isoenergetic single and mixed meals have shown that GI and/or glycemic load (GL) are stronger predictors of postprandial glycemia and insulinemia than carbohydrate content alone. In overweight individuals, a diet that combined modestly higher protein and lower GI carbohydrates was the most effective diet for prevention of weight re-gain. New observational studies have reported increased risks of coronary heart disease associated with higher intakes of carbohydrates from high GI foods. Epidemiological evidence has emerged linking dietary GI to visceral fat and inflammatory disease mortality. Summary There is growing recognition that replacing saturated fat with refined, high GI carbohydrates increases postprandial glycemia and may be detrimental for weight control and predisposition to cardiovascular and inflammatory disease. In contrast, low GI carbohydrates reduce risk.