Objective and BackgroundAlthough many studies on evaluating the safety of liver resection in obese patients have been conducted, the results remain contradictory. The aim of our study was to investigate the safety of overweight and obese patients undergoing liver resection for hepatitis B-related hepatocellular carcinoma in a large sample.MethodsIn a retrospective cohort with 1543 hepatitis B-related hepatocellular carcinoma patients, the subjects were stratified into four groups according to their body mass index(BMI): obesity(BMI≥28), overweight(BMI:24.0–27.9), normal weight(BMI:18.5–23.9) and underweight(BMI<18.5). The Dindo–Clavien classification system was used for grading complications. Clinical characteristics and operative outcomes were compared among the four groups. Risk factors for postoperative complications were evaluated by multivariate analysis.ResultsAccording to the category criteria of the Working Group on Obesity in China (WGOC) criteria, 73(4.7%) obese, 412(26.7%) overweight, 982(63.6%) normal weight and 76(4.9%) underweight patients were included in our cohort. Overweight and obese patients had more preoperative comorbidities such as hypertension(P<0.001). Mortality, total complications and complications classified by Clavien system were similar among the four groups except that the underweight patients had fewer total complications. However, postoperative wound complication was more common in overweight and obese patients(6.3% vs 2.5%,P<0.001,11.0% vs 2.5%,P = 0.001). Multivariate analysis revealed that BMI was not an independently significant factor for postoperative complications.ConclusionsLiver resection for obese and overweight patients is safe and BMI itself is not a risk factor for mortality and morbidity.