to present, on the basis of data relating to human evolution and genetic, anthropological and biomedical studies, the causes of the increased prevalence, in Western countries, of obesity and eating disorders (anorexia, bulimia and binge eating disorder); to explain and discuss the biological, metabolic, endocrine and neuroencephalic adaptive mechanisms related to the malnutrition by excess and by defect; to describe the nosographic, pathophysiological and clinical characteristics of eating disorders and the nutritional guidelines for the approach to these disease in different ages.