The epidemic of obesity concerns also children and adolescents. Excess weight increases the risk of metabolic complications, diabetes type 2, hypertension, cardiovascular disease, pulmonary and musculoskeletal disorders, psychosocial problems. Simple obesity leads to secondary endocrine disturbances. Long lasting insulin resistance and proinflammatory state induced by cytokines, which are produced in adipose tissue, play the main role in the development of obesity associated complications. Many disturbances can be reversed at the early stage, if even small weight loss is achieved.