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 programme (LCP) on the level of TBWL at 12 months and its maintenance at 60 months post bariatric surgery (BS), as well as its impact on operation time, hospital stay, surgical complications and obesity-associated pathology remission.

Methods: This retrospective, single-centre study analysed 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; 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 [BMI and TBWL] were better in the LCP group at 1 and 5 years. Additionally, patients achieving 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 TBWL 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 TBWL in comorbidity resolution in BS patients.