Gastrointestinal Hormones and Bariatric Surgery-induced Weight Loss

Obesity continues to be a major public health problem in the United States and worldwide. While recent statistics have demonstrated that obesity rates have begun to plateau, more severe classes of obesity are accelerating at a faster pace with important implications in regards to treatment. Bariatric surgery has a profound and durable effect on weight loss, being to date one of the most successful interventions for obesity. Objective: To provide updates to the possible role of gut hormones in post bariatric surgery weight loss and weight loss maintenance. Design and Methods: The current review examines the changes in gastro-intestinal hormones with bariatric surgery and the potential mechanisms by which these changes could result in decreased weight and adiposity. Results: The mechanism by which bariatric surgery results in body weight changes is incompletely elucidated, but it clearly goes beyond caloric restriction and malabsorption. Conclusion: Changes in gastro-intestinal hormones, including increases in GLP-1, PYY, and oxyntomodulin, decreases in GIP and ghrelin, or the combined action of all these hormones might play a role in induction and long-term maintenance of weight loss.