Contribution of Malabsorption to Weight Loss After Roux-en-Y Gastric Bypass: a Systematic Review

Roux-en-Y gastric bypass (RYGB) is traditionally classified as a combined restrictive and malabsorptive operation. This notion of the operation influences its technical variations and revisions for patients who do not achieve significant weight loss after this surgery. There is an increasing body of literature suggesting a role for appetite suppression mediated by neuro-hormonal signals after RYGB. The purpose of this paper was to systematically review published English language scientific literature to determine the role of malabsorption towards weight loss achieved with RYGB. This review finds that there is little or no malabsorption of carbohydrates or protein after RYGB but there is some fat malabsorption. Overall, malabsorption makes a little (approximately 11.0% in the early period) overall contribution to weight loss after RYGB.