Aims/hypothesis <p>Timely metabolic surgery improves glycaemic control and reduces cardiovascular risk for patients with type 2 diabetes. Young age is a known predictor of favourable metabolic outcome, but Roux-en-Y gastric bypass (RYGB) is often delayed owing to reported surgical and psychological risks in young adults. We hypothesised that use of RYGB in adults aged 18–35 years would result in higher rates of diabetes remission compared with older individuals, without an associated increase in morbidity.</p> Methods <p>We analysed prospective registry data from three expert centres where young adults (29.5±5 years) and older adults (48±6.8 years) (means ± SD) who were living with non-insulin-dependent type 2 diabetes underwent RYGB. Younger adults were matched in a 1:2 ratio to their older counterparts for duration of preoperative diabetes, sex, BMI and American Society of Anesthesiologists physical status score. The rates of diabetes remission and adverse events in both groups were compared five years postoperatively.</p> Results <p>A total of 79.1% (53/67) of the young adults and 76.9% (103/134) of the older adults attended the 5 year follow-up. Diabetes remission occurred earlier and more frequently in the young adult group, with an HR of 2.92 (95% CI 1.13, 7.59; <i>p</i>=0.027) and a median time to remission of 6 months (95% CI 3.1, 8.9), compared with 24 months (95% CI 10.9, 37.1) for older adults (<i>p</i>=0.001). There were no significant differences in all-cause adverse events, percentage weight change or loss to follow-up between groups.</p> Conclusions/interpretation <p>Diabetes remission occurred earlier and more frequently in young adults within the first 5 years after RYGB. Surgical complications, nutritional deficiency or suboptimal weight loss were not different in the investigated young adult group compared with the older adults.</p> Graphical Abstract <p></p>