['There is marked variability in weight loss achieved after laparoscopic Roux-en-Y gastric bypass (LRYGB) with little ability to predict pre-operatively poor weight-loss outcomes. In this study, we categorize the patterns of post-operative weight loss after LRYGB by using a novel method of measurement based on the time to weight-loss steady state (SS).', 'A bariatric database was retrospectively reviewed for patients who underwent a LRYGB from 01/2001-12/2010. SS was defined as the month when the patient had ≤3% excess weight loss (%EWL) or weight gain from the prior visit. Percent total weight loss (%TWL) and %EWL were compared based on time to SS.', 'The average time to SS was 15.5 months (n\u2009=\u2009178). A percentage of 7.3 of patients lost >5%EWL after achieving their SS weight. Patients with SS <12 months (n\u2009=\u200947) had a significantly lower %TWL and %EWL at SS and a 3-4-year follow-up compared to SS ≥12 months (n\u2009=\u2009131, p\u2009<\u20090.05 for all). Initial weight loss velocity (IWLV) and body mass index (BMI) were not significantly associated with the time to SS. Patients with a SS <12 months were significantly older than patients with SS ≥months (42.7\u2009±\u200910.5 versus 46.5\u2009±\u200911.8 years, p\u2009=\u20090.05).'] Does the Time to Weight-Loss Steady State After Gastric Bypass predict Weight-Loss Success?