Bariatric Surgeries, from Weight Loss to Weight Regain: A Retrospective Five-Years Cohort Study

Introduction: Bariatric surgery may lead to unsatisfactory weight loss, weight loss plateau, and even weight regain after various types of surgery. Despite the numerous studies, the mid-term results of surgery, after repetitive weight fluctuations remain a major concern. The aim of the present study was to determine the key time points of weight changes after three types of bariatric procedures, as well as to determine 5-year weight loss outcome after surgery. Methods: This is a retrospective cohort study including patients with morbid obesity conducted in the Minimally Invasive Surgery Research Center. The patients underwent one of the three types of bariatric surgeries including laparoscopic sleeve gastrectomy (LSG), Roux-en-Y gastric bypass (RYGB), and one-anastomosis gastric bypass (OAGB), who had been followed up for weight loss trend during 5 years postoperatively. Results: The mean excessive weight loss (%EWL) and total weight loss (%TWL) of 2,567 participants with obesity (mean age = 39.03, mean BMI = 45.67) in the first 6 months after surgery was independent of the type of surgery (p > 0.05). OAGB and RYGB showed significantly higher weight loss compared to LSG in ninth and 24th month after surgery, respectively (p < 0.05). The 5 years %WL could be comparable with %WL in 6, 9, and 12 months after LSG, RYGB, and OAGB, respectively. Conclusion: OAGB provides the fastest and highest %EWL and %TWL, while LSG induced the earliest and largest weight plateau and weight regain during 5-years post-surgery. The pattern of early weight loss could predict the mid-term outcome of bariatric surgery. So, early identification of suboptimal weight loss could enhance long-term weight loss.