There is a large bulk of evidence that using low glycemic index (GI) foods has a very significant impact on the amelioration of metabolic disturbances observed in diabetic and/or hyperlipidemic patients and in subjects affected by the metabolic syndrome. Studies bringing convincing evidence against this concept are very rare if any. Improvement is observed not only in postprandial blood glucose and insulin variations but also in circulating plasma lipid levels and the morphology and function of adipocytes. Using the concept of low GI foods in diet counseling of diabetic patients is not exclusive of other measures to improve postprandial and overall blood glucose control. On the contrary, the use of low GI foods should be considered as one of other means and tools available to improve diabetes control (such as other dietary modifications, use of specific and nonspecific drug therapy altering postprandial blood glucose). Among these therapies, the most promising ones are alpha-glucosidase inhibitors, glynides, rapid insulin analogues and in the near future the GLP1 analogue. Again, all these classes of drugs could be associated with one another in order to obtain a postprandial delta excursion target of not below 20 and not above 40-50 mg/dl blood glucose.