Does Preoperative Weight Loss Tip the Scale? Impact on Weight Loss after Bariatric Surgery with 5-Year Follow-up

Abstract

Introduction: Evidence for the benefits of preoperative weight loss on total weight loss after bariatric surgery (BS) is controversial. We aimed to determine the impact of preoperative total body weight loss (PrTBWL%) on postoperative total body weight loss (PoTBWL%). Methods: Data from 711 patients who underwent BS (LSG: 69.1%, LRYGB: 19.2%, revisions: 11.7%) between March 2016 and January 2022 were prospectively collected. All patients participated in a structured behavior modification, exercise, and low-calorie diet plan with a goal of 10% PrTBWL. Patients were grouped into < 7% or ≥ 7% PrTBWL. Results: The mean age was 43.97 years, mean BMI was 44.6 kg/m2, 86.35% were women and 52.46% were Hispanics. Patients with < 7% PrTBWL had lower PoTBWL% at 1-year (28.78% vs 34.95%, p =.0008), 2-year (26.11% vs 32.98%, p =.0008), 3-year (23.73% vs 30.46%, p =.0008), 4-year (21.55% vs 31.23%, p =.0012) and 5-year follow-up (18.08% vs 33.1%, p =.0008). Time from initial visit to BS was longer in < 7% PrTBWL group (210 vs 164 days, p =.0424). There was an independent linear effect of PrTBWL% on PoTBWL% (p <.0001, r=.4403) on multiple regression analysis. PrTBWL% was inversely correlated with operative time, but not with hospital stay. The 30-day morbidity and mortality was zero. Patients with preoperative BMI < 35 kg/m2 after preoperative weight loss were not denied surgery by their insurance. Conclusion: A significant linear association between PrTBWL% and up to 5-year PoTBWL%, irrespective of the type of BS, was observed. Preoperative weight loss does not contribute to insurance denials.