Behavioural weight management programmes can help people lose weight and reduce their risk of chronic diseases, but programmes led by specialists in clinical settings can be too costly for the NHS to deliver at the necessary scale. There is good evidence that primary care referral to commercially available open-group behavioural weight management programmes (like Weight Watchers or Slimming World) is a cost-effective option and 12-week referrals to these programmes are often used in the NHS. However, there is debate about whether a 12 week programme is sufficient to have a long term impact. In the WRAP trial we evaluated whether an extended referral (52 weeks) is more effective and cost-effective than a 12-week referral or a brief intervention. WRAP is the first trial of this type of scalable non-specialist intervention to have followed participants up for 5 years.
We recruited 1267 adults with overweight and obesity and randomly allocated them to one of three weight loss programmes: brief intervention (a self-help booklet), an open-group behavioural weight management programme (Weight Watchers) for 12 weeks, or the same programme for 52-weeks. Participants were followed up for 5 years, and we collected clinical measurements and self-reported data on psychosocial variables and health resource use at baseline, 3 months, 1 year, 2 years and 5 years.
At 1 year, both behavioural programmes led to greater weight loss than the brief intervention, but the 52 week programme led to greater weight loss and greater reductions in risk markers for diabetes than the 12 week programme and the brief intervention. Participants in the 52 week programme still had lower weight that the other groups at 2 year follow up. At 5 years some weight loss was maintained, but the difference between groups was no longer statistically significant.
We modelled the impact of the three programmes on weight-related diseases and health care costs over a lifetime. We found that both the 12-week and the 52-week programme were cost-saving. Despite higher initial costs, the 52-week programme is likely to save the NHS more money in the long term because of greater reductions in diabetes, heart disease and other weight-related diseases.
You can read more about the 5 year outcomes of the WRAP trial and the long term health economic modelling in the full paper in the Lancet Public Health. For more information on the main findings from the first 2 years of the trial you can read our earlier publication in the Lancet. A full list of publications from the WRAP trial is available here.
- Dr Amy Ahern – University of Cambridge
Five year follow up of the WRAP trial was completed in 2019. The main findings have been published and secondary analyses are ongoing. Data is available for sharing with other researchers for replication or additional analyses, as detailed below.
Applications are pending for passive long term follow up of participants via medical records.
From 31st October 2016, responsibility for the WRAP study transferred from MRC Human Nutrition Research to the MRC Epidemiology Unit, University of Cambridge. University of Cambridge are the sponsor and data controller for this trial. For more information about this please read our letter to participants.
The WRAP Study is led by the MRC Epidemiology Unit with responsibility for data and samples.
The WRAP trial was funded by the National Prevention Research Initiative through research grant MR/J000493. Five year follow up of the WRAP trial was funded by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research Programme (RP-PG-0216-20010).
The cost of the Weight Watchers programme and the costs of blood sampling and analysis were funded by Weight Watchers International as part of an MRC Industrial Collaboration Award.
Please see our Data Sharing pages.
If you would like to submit a data request to the Chief Investigators, please use the WRAP Data Request Form (MS Word).