Five-Year Outcomes of Laparoscopic Sleeve Gastrectomy and Roux-en-Y Gastric Bypass: A Comparative Study of Weight Loss and Nutritional Deficiencies

Introduction: Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) are the two most commonly performed metabolic and bariatric surgery (MBS) procedures worldwide, yet routine clinical practice long-term comparative data remain limited, particularly regarding gastroesophageal reflux disease (GERD), postoperative morbidity, and nutritional deficiencies. Methods We performed a retrospective observational cohort study including 860 consecutive adults undergoing primary laparoscopic SG (n = 502) or RYGB (n = 358) between 2014 and 2020 at a certified bariatric center. Outcomes were assessed at baseline and 3, 6, 12, 24, 36, 48, and 60 months. Longitudinal BMI, %EWL, and %TWL were analyzed using generalized linear mixed models; repeated binary outcomes were analyzed using generalized estimating equations. Results RYGB achieved greater long-term weight loss and lower BMI throughout follow-up (60 months: %EWL 84.0 ± 30.0 vs. 70.2 ± 26.9; %TWL 30.1 ± 10.3 vs. 26.8 ± 9.4). Clinical GERD was more prevalent after SG (60 months: 49.3% vs 29.9%); among individuals with baseline GERD, RYGB achieved higher GERD remission rates at 12 months (70.0% vs 21.9%). Major complications (Clavien–Dindo ≥ III) and readmissions were more frequent after RYGB (7.3% vs 1.8%; and 14.5% vs 6.7% within 12 months). SG was associated with higher rates of folate and vitamin D deficiency during the first two years. Conclusion At five years, RYGB provides superior weight-loss durability and more effective GERD control compared with SG, with an associated increase in major morbidity and readmission rates. SG remains an effective procedure but requires close long-term monitoring for reflux progression and specific micronutrient deficiencies.