Mechanisms of Weight Loss following Intestinal Bypass Surgery

Dramatic weight loss has been observed following intestinal bypass surgery. Initially, malabsorption was recognized as the major cause of weight loss. Only in recent years have investigators noted that the intestinal bypass could significantly reduce caloric intake, which largely or almost fully explains the weight loss following this procedure. The reduced energy intake as well as malabsorption are probably the major causes of weight loss after intestinal bypass surgery. Increased energy output has been proposed as a factor for weight loss, and more recently, it has been suggested that certain hormonal changes may play a role in regulating satiety and metabolic processes. This article examines these proposed factors that may impact on weight loss following intestinal bypass surgery.