[A practicing physician's view on obesity].

Overweight and obesity are worldwide problems, its health and psychosocial burden on the individual and on society are tremendous. Diagnosing obesity is rather easy, and is based on simple anthropometric measurements, such as body weight, height and waist circumference. The different classes of obesity are determined by body mass index, which, together with waist circumference and comorbid conditions and other risk factors determine the individual risk for mortality and morbidity. Obesity is due to genetic and environmental factors, mainly is the consequence of excess calorie intake and sedentary lifestyle. The fat mass of the body is under neuroendocrine control, the central controller is the hypothalamus. Leptin, produced by adipocytes in proportion to fat mass, is the afferent signal to the hypothalamus. Decreasing or increasing levels of leptin result in orexigen and anorexigen neurotransmission, which mediate efferent activation towards food consumption and energy storage, or towards food restriction and energy expenditure, respectively. The balance of these events and/or the ,set point" of the controller--if leptin resistance is present--is shifted towards higher body/fat mass in obesity. Management of obesity is complex, however, in all stages of obesity lifestyle changes are mandatory--including diet, exercise and behavior modification. Pharmacotherapy might be needed if lifestyle changes alone do not result an acceptable weight loss. For the long-term treatment of obesity sibutramin and orlistat are the available approved drugs. In case of morbid obesity (body mass index > 40 kg/m2, or > 35 kg/m2 plus comorbid conditions and other risk factors) surgery might be the treatment of choice. There are different surgical methods, among those a widely used method nowadays is the laparoscopic adjustable gastric banding procedure.