Ahern et al. BMC Public Health 2011, 11:434 http://www.biomedcentral.com/1471-2458/11/434 R E S E A R C H A R T I C L E Open Access Weight Watchers on prescription: An observational study of weight change among adults referred to Weight Watchers by the NHS Amy L Ahern†, Ashley D Olson†, Louise M Aston† and Susan A Jebb*† Abstract Background: The scale of overweight and obesity in the UK places a considerable burden on the NHS. In some areas the NHS has formed partnerships with commercial companies to offer weight management services, but there has been little evaluation of these schemes. This study is an independent audit of the Weight Watchers NHS Referral scheme and evaluates the weight change of obese and overweight adults referred to Weight Watchers (WW) by the NHS. Method: Data was obtained from the WW NHS Referral Scheme database for 29,326 referral courses started after 2nd April 2007 and ending before 6th October 2009 [90% female; median age 49 years (IQR 38 - 61 years); median BMI 35.1 kg/m2 (IQR 31.8 - 39.5 kg/m2). Participants received vouchers (funded by the PCT following referral by a healthcare professional) to attend 12 WW meetings. Body weight was measured at WW meetings and relayed to the central database. Results: Median weight change for all referrals was -2.8 kg [IQR -5.9 - -0.7 kg] representing -3.1% initial weight. 33% of all courses resulted in loss of ≥5% initial weight. 54% of courses were completed. Median weight change for those completing a first course was -5.4 kg [IQR -7.8 - -3.1 kg] or -5.6% of initial weight. 57% lost ≥5% initial weight. Conclusions: A third of all patients who were referred to WW through the WW NHS Referral Scheme and started a 12 session course achieved ≥5% weight loss, which is usually associated with clinical benefits. This is the largest audit of NHS referral to a commercial weight loss programme in the UK and results are comparable with other options for weight loss available through primary care. Background A quarter of UK adults are obese and a further 41% men and 32% women are overweight [1]. If current trends continue, almost nine in ten adults will be over- weight or obese by 2050 [2]. Weight-related morbidity already places a substantial burden on the NHS, with direct costs estimated at £991-1124 million per annum [3]. Weight loss of ≥5% of initial weight is associated with reductions in health risk [4], and a number of behavioural and pharmacological treatments are avail- able for adult weight management [5]. However, many treatment options do not offer the capacity to be * Correspondence: Susan.Jebb@mrc-hnr.cam.ac.uk † Contributed equally MRC Human Nutrition Research Unit, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge, CB1 9NL, UK delivered at the necessary scale, while in other cases the NHS may lack the resources to achieve a meaningful population-level impact [6]. NICE guidelines recommend that primary care provi- ders should discuss with patients all treatment options meeting best practice guidelines, including commercial programmes [4]. However, at present, there is a paucity of data on the effectiveness of weight management options in primary care and providers need reliable information from which to select appropriate services [4]. Weight Watchers (WW) is a lifestyle-based group weight loss programme which offers weekly meetings at community venues, a nutritionally-balanced eating plan and advice on physical activity, aiming to produce moderate weight loss. A rando- mised clinical trial in the USA showed that WW led to greater weight loss over 12 months than a guided self-help © 2011 Ahern et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.