Age is sometimes a barrier for acceptance of patients into a hospital-based obesity service. Our aim was to explore the effect of age on the ability to lose weight through lifestyle interventions, implemented within a hospital-based obesity service.Cross-sectional study in a cohort of randomly selected patients with morbid obesity (n=242), who attended our hospital-based obesity service during 2005-2016 and received only lifestyle weight loss interventions. Primary outcome measures were percentage weight loss (%WL) and percentage reduction in Body Mass Index (%rBMI) following implemented lifestyle interventions. Data were stratified according to patient age at referral: group 1 (age<60 years, n=167); group 2 (age≥60 years, n=75). Weight loss was compared between groups and correlations with age at referral were explored.The duration of hospital-based weight loss interventions ranged between 1 and 143 months (mean: 38.9 months; SD: 32.3). Baseline BMI at referral differed significantly between groups 1 and 2 (49.7kgm-2 [SD: 8.7] vs 46.9kgm-2 [SD: 6.1], respectively; P<0.05). Following implemented lifestyle interventions, between groups 1 and 2 there were no differences in %WL (6.9% [SD: 16.7] vs 7.3% [SD: 11.60], respectively; P=NS) or %rBMI (8.1% [SD: 14.9] vs 7.8% [SD: 11.7], respectively; P=NS). Overall, there was no significant correlation between patient age at referral and %WL (r=-0.13, P=NS).Older age does not influence the success of weight loss through the implementation of lifestyle modification within a hospital-based obesity service. Therefore, age per se should not influence clinical decisions regarding acceptance of patients to hospital-based obesity services.