RESUMEN
There is limited evidence of the effectiveness of non-surgical interventions for severe obesity. Our aim was to evaluate a group intervention delivered by a National Health Service (NHS) specialist weight management service to contribute to the evidence base and inform the development of future services. Participants in this prospective cohort study were patients attending NHS Grampian Specialist Weight Management Services. The intervention was an interactive 12-session group programme based on evidence-based psychological model, with combined dietetic and psychological knowledge and support provided. The primary outcome was mean weight change at the end of the intervention and for 12-mo follow-up (including programme completers, baseline observation carried forward [BOCF], last observation carried forward). Secondary outcome measures included mood, anxiety, binge eating and quality of life. A total of 166 patients accepted a place on the group programme, mean body mass index was 48.9 kg/m2 . Mean weight loss at 6 mo was 5.6 kg and 35.2% of those who completed the group (n = 88) lost ≥5%. Using BOCF, 18.7% lost ≥5% at 6 mo. Those who remained in the programme maintained their weight loss 12 and 18 mo after the start of the intervention. Significant improvements were also found in psychological variables, including reduced depression, anxiety, binge eating and improved emotion regulation. This real-world evaluation of an NHS intervention for patients with severe obesity suggests that individuals who engage achieve a moderate weight loss, which most maintain a year later, although further research is needed to strengthen this conclusion.