307 Dietary Intake of Soft and Liquid Calories Is Associated With Weight Regain After Roux-en-Y Gastric Bypass

Abstract

Background: Roux-en-Y gastric bypass (RYGB) renders the stomach less capable of performing mechanical breakdown of solid food into chyme, decreasing the proportion of calories later absorbed by the intestine. Additionally, the pyloric sphincter is substituted by an always-patent gastrojejunal anastomosis. Thus, soft and liquid calories quickly exit the pouch, resulting in rapid caloric absorption without induction of satiety. Intake of soft or liquid calories may circumvent surgical mechanisms of action and exploit limitations of the Rouxen-Y anatomy, leading to weight regain. Aim: To analyze the relative effects of nutritional and lifestyle factors on weight regain in patients after RYGB. Methods: 100 post-RYGB patients seen in the bariatric clinic for follow-up. Patients were asked to list dietary intake and eating habits for the prior 24 hours, and to report the instances of aerobic exercise during the prior seven days. Demographic data and pre-RYGB, nadir, and current weight data were abstracted from clinic records. Multiple linear regression was performed using STATA 12. Results: 100 patients (49.0 ±1.1 yr, 4M/96F, BMI 49.1 ±1.1 kg/m2) underwent RYGB with postoperative weight loss of 78.1 ±2.5% excess weight loss (EWL) at nadir (loss of 104.8 ±3.8 lb). Patients reached nadir at 18.5 ±1.4 months. The visit occurred at a mean 6.7 ±0.3 yr after RYGB. Patients regained 26.0 ±2.4% of lost weight to result in BMI of 35.6 ±1.0 at the time of the visit. Multiple linear regression for percentage of weight regained fromnadir was performedwith potential predictors including BMI, time since RYGB, instances of exercise, whether patient wakes up to eat, and dietary categories. BMI and intake of softconsistency foods or liquid calories were significant independent predictors for weight regain. Regression results are shown in Table 1. Conclusions: After controlling for patient characteristics and exercise habits, intake of soft-consistency foods or li'quid calories predicts weight regain after RYGB. Gastric bypass patients may benefit by limiting the intake of soft foods and liquid calories. Table 1: Multiple linear regression for % weight regained