Mechanisms of Action of Bariatric Surgical Procedures

Bariatric surgery can effectively induce durable weight loss and can reduce the risk of obesity-associated complications, including type 2 diabetes mellitus (T2DM). Bariatric procedures fundamentally alter physiology, and in those with diabetes, bariatric surgery can affect insulin sensitivity and insulin secretion, resulting in remission of diabetes in many recipients. The action of each procedure differs, and the mechanisms by which each procedure produces weight loss and alters physiological mechanisms, such as glucose homeostasis, are multiple and often integrated. The known mechanisms include gut hormone mediated changes affecting appetite, insulin dynamics, food preferences, and energy expenditure. In this review, we outline the current knowledge on the putative mechanisms of weight loss and glucose homeostasis after the most commonly performed bariatric operations.