Despite significant achievements in treatment modalities and preventive measures, diabetes has been increasing exponentially. Reduction in both fasting and prolonged postprandial glycemia is of paramount importance in the disease prevention and the delay of diabetic complications. Blood glucose concentration can be reduced by dietary means, and may be influenced by factors such as type and amount of carbohydrate, nature of starch, quantity of protein and fat, dietary fiber content, method of food processing, particle size and food form. Glycemic index (GI) is a measure of the blood glucose-raising ability of the available carbohydrate in foods. Although evidence is often insufficient and individual differences occur, prospective studies and clinical trials have shown that low-GI diets may reduce the risk of diabetes and improve glycemic control in diabetes.