A brief intervention for weight management in primary care: study protocol for a randomized controlled trial

BACKGROUND: Obesity affects 25% of the UK adult population but modest weight loss can reduce the incidence of obesity-related chronic disease. Some effective weight loss treatments exist but there is no nationally available National Health Service (NHS) treatment service, and general practitioners (GPs) rarely discuss weight management with patients or support behavior change. Evidence shows that commercial weight management services, that most primary care trusts have 'on prescription', are more effective than primary care treatment.

METHODS/DESIGN: We propose a controlled trial where patients will be randomized to receive either the offer of help by referral to a weight management service and follow-up to assess progress, or advice to lose weight on medical grounds. The primary outcome will be weight change at 12-months. Other questions are: what actions do people take to manage their weight in response to the two GP intervention types? How do obese patients feel about GPs opportunistically discussing weight management and how does this vary by intervention type? How do GPs feel about raising the issue opportunistically and giving the two types of brief intervention? What is the cost per kg/m2 lost for each intervention? Research assistants visiting GP practices in England (n = 60) would objectively measure weight and height prior to GP consultations and randomize willing patients (body mass index 30+, excess body fat, 18+ years) using sealed envelopes. Full recruitment (n = 1824) is feasible in 46 weeks, requiring six sessions of advice-giving per GP. Participants will be contacted at 3 months (postintervention) via telephone to identify actions they have taken to manage their weight. We will book appointments for participants to be seen at their GP practice for a 12-month follow-up.

DISCUSSION: Trial results could make the case for brief interventions for obese people consulting their GP and introduce widespread simple treatments akin to the NHS Stop Smoking Service. Likewise, the intervention could be introduced in the Quality and Outcomes Framework and influence practice worldwide.

TRIAL REGISTRATION: Current Controlled Trials ISRCTN26563137.