Objective <p>In this interventional weight loss study, health-related quality of life (HRQoL), anxiety, depression and fatigue were compared at baseline (BL) and at 12 months (M12) in patients with psoriatic arthritis (PsA) and controls.</p> Methods <p>PsA patients (<i>n</i> = 39) between 25 and 75 years of age, with body mass index (BMI) ≥ 33&#xa0;kg/m² were included in a weight loss intervention with very low energy diet (VLED) for 12 or 16 weeks depending on BL BMI &lt; 40 or ≥ 40&#xa0;kg/m². The 36-item short-form health survey (SF-36) was used to assess HRQoL. Anxiety and depression were assessed by the Hospital Anxiety and Depression Scale. Assessments were done at BL, M3, M6 and M12. As controls (<i>n</i> = 39), obese individuals, already planned for VLED treatment were recruited and matched for sex, age and weight to the PsA patients.</p> Results <p>In PsA patients, physical HRQoL, as demonstrated by the physical component summary (PCS) of SF-36, improved from median (IQR) 34 (25–45) at BL to 43 (34–50) at M12, <i>p</i> = 0.009. No significant effect on mental HRQoL, demonstrated by the mental component summary (MCS) score, was seen. Similarly in controls, PCS significantly improved (median IQR, 44 (36–50) at BL to 52 (44–55) at M12, <i>p</i> &lt; 0.001), whereas no significant improvement was seen in MCS. Anxiety and depression decreased significantly in both PsA patients and controls.</p> Conclusions <p>The weight loss intervention was associated with significant improvements in physical HRQoL, as well as anxiety and depression, in PsA patients and controls.</p> Trial registration <p>ClinicalTrials.gov identifier: NCT02917434, registered on September 21, 2016, retrospectively registered.</p>