Assessment of weight change patterns following Roux en Y gastric bypass, one anastomosis gastric bypass and sleeve gastrectomy using change-point analysis

Abstract

Abstract We aimed to assess the weight loss trend following Roux en Y Gastric Bypass (RYGB), One Anastomosis Gastric Bypass (OAGB), and Sleeve Gastrectomy (SG), utilizing a change-point analysis. A retrospective cohort study was conducted on 8640 patients, from 2009 to 2023. The follow-up period extended to 7 years, with a median follow-up of 3 years (interquartile range: 1.4–5). Following metabolic bariatric surgery, four weight loss phases (three change points) were observed. The primary, secondary, and tertiary phases, transitioned at 12.64–13.73 days, 4.2–4.8 months, and 11.3–13.1 months post-operation, respectively, varying based on the type of procedure. The weight loss rate decreased following each phase and plateaued after the tertiary phase. The nadir weight was achieved 11.3–13.1 months post-procedure. There was no significant difference in the %TWL between males and females, however, males achieved their nadir weight significantly earlier. Half of the maximum %TWL was achieved within the first 5 months, with the greatest reduction rate in the first 2 weeks. Our findings inform healthcare providers of the optimal timing for maximum weight loss following each surgical method and underscore the importance of close patient monitoring in the early postoperative period.

Keywords

• Bariatric surgery
• Weight loss
• Gastric bypass
• One anastomosis gastric bypass
• Roux-en-Y gastric bypass
• Sleeve gastrectomy