The obesity and the metabolic disorders associated characterize the metabolic syndrome, which has increased at an alarming rate around the world. It is known that environmental and genetic factors are involved in the genesis of obesity. Peroxisome Proliferator-Activated Receptors (PPARs) stand out among these factors. They compose the nuclear receptor superfamily and there are in three isoforms (PPARα,PPARβ/δ and PPARγ), which play an important role in the regulation of the metabolism of carbohydrates, lipids and proteins. The present review aims to understand the relationship between the diet, the PPARs and the control of the blood glucose and body weight, since the understanding about the mechanisms by which these receptors act may benefit the development of the strategies aiming at prevention and elaboration of therapeutics actions which are more effective for the treatment of obesity and diabetes.