Childhood overweight and obesity are major health problems with immediate and long-term consequences of staggering magnitude. Despite this, there are few preventive and therapeutic strategies of proven effectiveness available to public health and clinical practitioners. Accruing such evidence is currently and appropriately a health policy priority, but there is an urgent need to intervene even before comprehensive solutions are fully established. The aim of this Clinical Report on Overweight Children and Adolescents is to present information on current understanding of pathogenesis and treatment of overweight and obesity. We report on the epidemiology, molecular biology and medical conditions associated with overweight; on dietary, exercise, behavioral, pharmacological and surgical treatments; and on the primary prevention of overweight in children and adolescents.