Dietary composition is one of the factors that is influencing the current epidemie of obesity. Carbohydrate composition and protein content in weight reduction diets háve been discussed in recent years. The glycaemic index of carbohydrates is one of the most controversial issues. The effect of glycaemic index (GI) on weight is explained by a higher sérum glucose and insulin response induced by high GI carbohydrates, which promote lower fat oxidation and higher fat storage in comparison with low GI carbohydrates. Therefore foods with a high GI could contribute to the maintenance of excess weight in obese individuals and during weight reducing diets; high GI foods can also predispose obesityprone subjects to weight gain. But in studies using low and high glycaemic index foods equivocal results were shown. In this review, studies comparing the effects of meals with low and high glycaemic index carbohydrates are discussed. The European DIOGenes study (Diet, Obesity and Genes) focuses on the role of glycaemic index and protein proportion in weight management in parents and their children, and should assist in clarifying this issue.

        Key words: obesity, glycaemic index, DIOGenes, diet, carbohydrates, proteins.