Title: Randomised controlled trial of habit-based advice for weight control in general practice (The 10TT Trial)
Funder: Medical Research Council

Abstract: Increases in obesity prevalence over recent decades have made weight control a key issue for public health. The cross-government strategy Healthy Weight, Healthy Lives identifies primary care as the ?first port of call? for advice about weight control, creating an urgent need for simple, effective interventions that can be delivered by the primary care team without specialist therapeutic skills. A novel approach to health behaviour change draws on ?habit-theory?. Diet and activity behaviours are often loosely termed ?habits?, but few behaviour change interventions are based explicitly on the theory of habit-formation. The essential feature of habits is that they are automatic (i.e. require minimal deliberate effort). Habits are learned responses to environmental cues resulting from multiple repetitions in a consistent environmental context. They are more resistant to extinction than non-habitual behaviours because they don?t depend on deliberate self-control. There has been growing interest in the role of habits in health behaviours, but existing research focuses largely on bio-behavioural mechanisms In one of the first attempts to translate habit theory to practice, we used it to develop a simple weight-control programme. We took a set of simple behaviours known to be associated with weight control and presented them in leaflet format (TenTopTips) along with advice on how to make them habitual (repetition in consistent contexts, self-monitoring until automaticity developed). No further clinical contact was involved. Users involved in the development found it easy and effective. A trial in a volunteer population (n=104) showed that individuals randomised to receive the TenTopTips leaflet lost significantly more weight than the wait-list control group (-2.0kg vs -0.4kg in an intention-to-treat analysis; Lally et al, 2008). Weight loss was maintained over 32 weeks follow-up, with 54% (ITT=26%) achieving the 5% weight loss associated with health benefits. Weight loss was associated with increased automaticity of the behaviours, suggesting that development of habits underpinned the intervention?s effectiveness. These results provide a strong basis for conducting a controlled trial of the effectiveness of the TenTopTips intervention in Primary Care and incorporating clinical outcomes and health-economic analyses. This application is for an individually-randomised, controlled trial of 520 obese adults across 10 General Practices comparing the TenTopTips leaflet with a usual-care control condition. The primary outcome is loss of body-fat, with secondary outcomes including clinical risk-factors, behaviour change and automaticity, and quality-of-life. A full cost-effectiveness analysis will be carried out and surveillance will continue for 24 months to establish longer-term maintenance.


Research activity codes: 3.1 PRIMARY PREVENTION INTERVENTIONS TO MODIFY BEHAVIOURS OR PROMOTE WELL-BEING
Health categories: STROKE;CANCER AND NEOPLASMS;METABOLIC AND ENDOCRINE;CARDIOVASCULAR;ORAL AND GASTROINTESTINAL