Obesity, defined as a body mass index>or=30 kg/m2, is a modern epidemic and is increasing worldwide. Depending on the genetic makeup, lifestyle factors such as high-caloric nutrition, lack of physical activity and certain psychosocial conditions are the main determinants of its manifestation and progression. Numerous epidemiologic studies consistently show that obesity is associated with many comorbidities and, moreover, reduces quality of life and life expectancy. For this reason, there is clear need for an evidence-based treatment considering the individual risk. Each treatment program consists of a hypocaloric diet, increase in physical activity, a behavior modification training and, eventually, weight-lowering drugs. An effective treatment of this condition may not only significantly improve most somatic and psychological comorbidities of the patients but also prolong life.