Early Post-operative Weight Change After Roux-en-Y Gastric Bypass Predicts Weight Loss at 12-Month Follow-up

Introduction: Sub-optimal weight loss following Roux-en-Y gastric bypass (RYGB) represents an important clinical challenge in a significant number of patients. Early identification of such patients would be advantageous, as it could aid in the selective implementation of targeted adjunct interventions during the first post-operative year. Methods: Clinical audit data from 1137 patients undergoing RYGB between 2013 and 2016 at the Instituto Sallet in Brazil were prospectively registered in an online database (BOLD) and analyzed. Results: Forty-eight percent of patients achieving less than 5% total weight loss after the first post-operative month achieved a 20% total weight loss at 1 year (n = 626; OR = 0.6 CI = 95%). Eighty-three percent of patients losing between 5 and 10% at 1 month and 95% of patients losing greater than 10% at 1 month had lost at least 20% of total body weight after the first post-operative year. Forty-four percent of patients achieving less than 10% total weight loss after the third post-operative month achieved 20% total weight loss at 1 year (n = 494; OR = 0.3 CI = 95%). Conclusion: Total bodyweight reduction after RYGB of < 5% at 1 month and < 10% at 3 months is associated with suboptimal weight loss at 1 year. These results reinforce findings from other studies reporting that patients tend to follow a common weight loss trajectory. Identifying the patients with weight trajectory requiring adjunct therapies early on is crucial so appropriate adjustments can be made to post-operative care.