Across 1,498 adults followed for a median of 53–66 months after bariatric surgery, all three procedures achieved comparable nadir weight loss (~38% total weight lost), but trajectories diverged markedly thereafter. At last follow-up, median total weight loss was 33.6% for one anastomosis gastric bypass (OAGB), 31.7% for Roux-en-Y gastric bypass (RYGB), and 29.6% for sleeve gastrectomy (SG). Critically, OAGB carried 66% lower odds of recurrent weight gain ≥10% from nadir versus SG (OR 0.34, 95% CI 0.18–0.64), with propensity-score-matched analysis confirming a striking absolute risk difference: 37.7% vs 61.6% experiencing significant regain.
Sleeve gastrectomy currently dominates global bariatric practice precisely because of its technical simplicity and favorable short-term profile — but accumulating evidence consistently shows its Achilles heel is long-term weight durability. This large multicenter Turkish cohort reinforces that narrative. The OAGB finding is clinically meaningful: a number needed to treat of ~5 to prevent one case of substantial regain is compelling for a surgical intervention. However, caution is warranted. The OAGB subgroup (n=53) is too small for robust effect estimates, the retrospective design precludes causal inference, standardized remission endpoints were not applied, and selection bias likely influenced which patients received each procedure. RYGB's intermediate position aligns with prior literature. For adults weighing long-term surgical options, this study adds evidence that OAGB may offer superior weight maintenance, but prospective head-to-head trials with standardized outcomes remain essential before practice should shift.