The effect of preoperative body weight loss on 5-year bariatric surgery outcomes

Objectives This study aimed to evaluate the effect of preoperative total body weight loss (TBWL) following a structured 6-month lifestyle change program (LCP) on operation time, hospital stay, surgical complications, obesity-associated pathology remission, and the achievement and maintenance of BWL at 12 and 60 months post-bariatric surgery (BS). Methods This retrospective, single-center study analyzed patients undergoing primary BS between 2013 and 2014. Outcomes were compared between patients participating in the LCP (LCP group) and those receiving standard preoperative education (Control group: CG). Data collected included anthropometric measurements, obesity-related pathologies, surgical complications, and weight-related outcomes. Results Among 340 BS procedures performed, 165 patients met the inclusion criteria, with 59 in the LCP group and 106 in the CG. The mean age was 47 (±11.6) years in the LCP group and 45 (±11.1) years in the CG with no significant differences in baseline clinical characteristics. At surgery, the LCP group showed significant weight reduction (-5.9 kg vs. -0.72 kg in controls, p = 0.008) and their BMI was significantly lower (46.55 vs. 49.47 kg/m², p = 0.002). Postoperatively, weight-related outcomes [BWL, BMI and TBWL] were better in the LCP group at 1 and 5 years. Additionally, patients achieved a preoperative TBWL >5% demonstrated a significantly lower weight and BMI, along with a higher postoperative TBWL. Surgical complications were minimal, with no significant differences in 30-day complication rates. We did not observe a greater resolution of comorbidities in patients who participated in the LCP or those who achieved a preoperative TBWL > 5%. Conclusions while current evidence suggests that preoperative BWL provides short-term benefits, our data suggest this may also be the case for TBWL in the long-term. Further research is needed to fully elucidate the role of preoperative BWL in comorbidity resolution in BS patients.