The postprandial activation of the peripheral sympathetic nervous system is crucial to maintain cardiovascular homeostasis. A contribution of postprandial sympathetic activation to the thermic effect of food is not always evident and depends on the size and composition of the meal, with carbohydrates having the clearest effect. Signals related to food intake from various origins (e.g. gut, hepatoportal area, baroreceptors) are integrated in the brain and result in increased peripheral sympathetic outflow. It is of interest to further explore the role of diet composition in the level of sympathetic activation during the day in view of the potential role of adrenergic overactivity in the pathogenesis of obesity and its cardiovascular and metabolic comorbidities.