Mechanisms of bariatric and metabolic surgery

Under the circumstances of rising numbers of patients suffering obesity and its related comorbidities, bariatric surgery becomes a more and more important treatment option. Thereby the Roux-en-Y gastric bypass (= RYGB) and sleeve gastrectomy (= SG) are the most frequent operations performed in this field. The significant weight loss and the observed changes in food consumption cannot be explained by mechanical restriction and caloric malabsorption as initially assumed, but seem to be rather based on a complex interplay of endocrinological, neurological and behavioral mechanisms. It is thus the aim of this article to provide a short overview on the most important physiological mechanisms of bariatric and metabolic surgery considering the available data to date.