Morbid obesity represents a serious health issue in Western countries, with a rising incidence and a strong association with increased mortality and serious co-morbidities, such as diabetes. Surgical interventions, such as laparoscopic gastric banding have been developed with the aim of providing a laparoscopic placed device that is safe and effective in generating substantial weight loss. By investigation of the incretin effect, the secretion of GIP and GLP-1, the insulin response and sensitivity and the beta-cell responsiveness to glucose in 10 obese patients without type 2 diabetes before and after laparoscopic gastric banding the aim of this project is describe the pathophysiological mechanisms involved in the amelioration of glucose homeostasis during long-term weight loss.