The impact of preoperative weight loss on outcomes following laparoscopic Roux-en-Y gastric bypass (LRYGB) is a controversial issue. We evaluated our outcomes of LRYGB in patients who lost different amount of weight prior to surgery.

Patients who underwent primary LRYGB were divided in three groups on the basis of preoperative weight loss percentage. Group A comprised 166 patients, who lost <5 % of their weight preoperatively; group B comprised 239 patients who lost >5 to 10 % and group C included 143 patients who lost >10 %. Intra- and postoperative complications at 30 days, hospital stay, and outcomes were evaluated.

Significant difference was found in operative (mean ± SD) time [104.43 ± 36.40 min in group A, 80.08 ± 23.07 min in group B, and 76.99 ± 23.23 min in group C; p < 0.001 in group A versus group B or group C; p  = 0.210 in group B versus group C]. Difference in hospital stay was significant (3.33 ± 3.22 days in group A, 2.10 ± 2.77 in group B, and 1.87 ± 1.44 in group C; p < 0.001 in group A versus groups B or C). Overall postoperative morbidity rate was 33.13 % in group A, 19.25 % in group B, and 11.89 % in group C, with significant difference in group A versus groups B or C (p = 0.002 and p < 0.001). Mean excess weight loss was significantly higher (72.7 %) in group C versus group A (63.1 %) (p = 0.015) at 12 months.

Weight loss >5 % prior to LRYGB may reduce morbidity, and preoperative weight loss >10 % may improve weight loss outcomes at 1-year follow-up.