Objectives To investigate the effect of 2 years of add-on prednisolone 5 mg/day on body weight and composition in patients with active rheumatoid arthritis (RA) aged 65+ and the relation with disease activity.Methods The Glucocorticoid Low-dose Outcome in RheumatoId Arthritis trial, a pragmatic, placebo-controlled, double-blind, randomised controlled trial investigated the balance of benefit and harm of 2 years of prednisolone 5 mg/day added to standard care in 451 patients with active RA aged 65+. In the current study, 449 patients were included, and body weight and Disease Activity Score of 28 Joints were measured at baseline and after 3, 6, 12, 18 and 24 months. In 57 patients, body composition was assessed at baseline and after 2 years with dual-energy X-ray absorptiometry. Data were analysed with longitudinal mixed models.Results The mean (95% CI) change in body weight was 0.9 (0.3 to 1.6) kg in the prednisolone group and –0.4 (–1.1 to 0.2) kg in the placebo group (difference 1.3 (0.5–2.2), (p