Press release: May 2017

New study in The Lancet: Weight Watchers is more effective than a brief intervention and self-help
Published 3 May, 2017

-Weight loss sustained two years down the line-

A new, two-year UK-based study published today (Thursday 4th May) in The Lancet indicates that overweight and obese adults referred to Weight Watchers®, the world’s leading community based weight management provider, for one year lost more weight for longer and had greater reductions in diabetes risk than those who were referred for a 12-week programme, and lost more than twice as much weight as those who received brief advice and self-help materials.

The large independent study, looked at weight loss among 1267 participants randomised to attend Weight Watchers for a 12-week or one year period, or to receive a brief intervention, alongside self-help materials and regular weigh-ins. It also analysed the cost effectiveness of these programmes. The study was conducted by research teams led by Dr. Amy Ahern, at the University of Cambridge; Professor Jason Halford and Dr. Emma Boyland at the University of Liverpool, and Professor Susan Jebb and Professor Paul Aveyard at the University of Oxford and involved 26 GP practices across the UK.

People assigned to the brief intervention were given a 32-page booklet of self-help weight management strategies with follow up weigh-ins at three, 12 and 24 months. Those assigned to Weight Watchers were asked to attend weekly meetings and had access to internet resources for the duration of their programme, 12-weeks or one year at no cost to themselves. 

Participants assigned to a year of Weight Watchers lost, on average, more than twice as much weight as those in the brief intervention group[1]. They were also more likely to lose 5% and 10% or more of their initial weight, which are milestones that are associated with levels shown to have significant health benefits[2]. The superior weight losses in the one year Weight Watchers group were sustained even two years down the line.

Using microsimulation modelling, the study also estimated that over a 25-year period, the 12-week programme could be cost-saving for the NHS, and that, despite the greater initial investment, the one year programme is cost effective compared with the 12-week programme[3].

The 12-week programme was predicted to prevent more illnesses than the brief intervention due to the greater weight loss. Over 25 years, the cost to the NHS of providing the programme would be more than offset by the later savings as a result of reductions in disease.

Offering a year-long programme was estimated to prevent an additional 1786 cases of disease (including 642 fewer cases of hypertension, 373 fewer cases of diabetes and 104 fewer cases of heart disease) for every 100,000 people, compared to the 12-week programme. And, although it was more expensive upfront, the study shows that the year-long programme is cost-effective by preventing more cases of weight related illness.

The study shows that Weight Watchers one year programme achieved improvements in type 2 diabetes risk factors comparable to more intensive (and costly) health professional-led interventions[4]. The data also demonstrates how a referral to Weight Watchers can be successful on a large scale in helping those with excess weight achieve medically significant health benefits, reducing the strain on the NHS.

This evidence comes as the problems of obesity worldwide result in huge demands on medical services, with the disease taking over smoking as the leading cause of preventable death. The worldwide prevalence of obesity more than doubled between 1980 and 2014 and World Health Organisation estimates that close to two billion people worldwide are currently overweight and more than 600 million are obese with 62% of the adult UK population being classified as overweight or obese. Healthcare systems around the world whether public, private or combination are under pressure, and have a desire to respond to the obesity crisis.

Lead author Dr. Amy Ahern of the MRC Epidemiology Unit at the University of Cambridge says: “We’ve seen before that a 12-week programme can help people lose weight, but for the first time we’ve shown that extending this to a full year leads to greater weight loss over a longer period and a lower risk of diabetes. Although the initial costs of the year-long programme are greater, it’s very likely that it will be good value for money over the long term because of the reduction in weight-related illnesses.”

Zoe Griffiths, Head of Programme and Public Health, Weight Watchers UK says: “Obesity is a chronic disease which puts enormous pressure on limited and already overburdened NHS resources. There is a clear need for practical treatments that are proven effective, affordable and scalable which have a population-wide impact. Trials like this are vital to identify effective solutions to tackle obesity and provide the evidence to inform policy decisions.

“For the first time this study has shown that referring people to Weight Watchers is potentially cost-saving – it could actually save the NHS money. Unfortunately, the provision of GP referral schemes to services like Weight Watchers is patchy across the nation; with budgets being squeezed, many local authorities have no services in place at all. With government cuts, this situation is getting worse and worse, yet could offer the NHS one way of saving money.    

Griffiths continues: “Once again, it has been proven that Weight Watchers is a highly effective weight management programme and is part of the solution to help tackle the high and rising levels of overweight and obesity. The study adds significant evidence and credibility for health professionals and Weight Watchers working together to transform the health of the nations in the short and long term. Success comes from GPs and Weight Watchers working together; GPs raising the issue of weight and referring them to a programme that gives them intense support via weekly meetings and digital tools and community. ”

The study design was a randomised, prospective, controlled clinical trial, the gold standard in medical research.

As further proof of the effectiveness and scalability of this public health approach, GPs across the UK have been referring overweight and obese patients to Weight Watchers for 12 years. An independent audit of this real world experience, published in BMC Public Health in June 2011, shows that it consistently delivers effective weight loss outcomes even across geographies[5].


For more information please contact Sophie Pettifer on / 0207 841 7070 

Notes to Editors

About Weight Watchers International, Inc.

Weight Watchers International, Inc. is one of the most recognised and trusted brand names among weight-conscious consumers. Weight Watchers provides commercial weight management services through a global network of Company-owned and franchise operations and offers innovative, digital weight management products through its websites, mobile sites and apps. These services and products are built on the WW weight-loss programme, which helps millions of people around the world lose weight through sensible and sustainable food plans, activity, behaviour modification and group support. Weight Watchers has an unparalleled network of service providers to assist members on their journey and also offers a wide range of products, publications and programmes for those interested in weight loss and healthier living.


The study was funded by the National Prevention Research Initiative (a consortium including government departments, research councils and major medical charities). Weight Watchers International funded the analysis of the blood samples taken as part of the study, as part of an MRC Industrial Collaboration Award. The intervention used was provided free to the NHS by Weight Watchers.

Conflicts of Interest

ALA, SAJ, EJB, BRM and JCGH have received research funding to their institutions from Weight Watchers International and have given and received hospitality from providers of commercial weight loss services on a small number of occasions. PA and SAJ have conducted another publicly funded trial in which part of the intervention was delivered by and donated free by Slimming World and Rosemary Conley, and they are principal investigators on a trial funded through a grant to the University of Oxford from Cambridge Weight Plan. JCGH is Principal Investigator on studies funded through research grants to the University of Liverpool from the California Prune Board, Ingredion and American Beverage Association (ABA), and has studentships funded through BBSRC and ESRC with Unilever, Coca-Cola, and Tate & Lyle. JCGH provides expertise on health, weight management and appetite control to the food and beverage, commercial weight management, pharmaceutical and ingredient sectors.

[1] Mean weight change at 12 months was -3.26kg for brief intervention, -4.75kg in the 12-week programme and -6.76kg in the 52-week programme.

[2] At 12 and 24 months, participants in the 52-week programme had greater reductions in waist and fat mass than participants in the 12-week programme or brief intervention group. At 12 months, participants in the 52-week programme had greater reductions in HbA1c than those in the 12-week programme and brief intervention and greater reductions in fasting plasma glucose than those in the 12-week programme and brief intervention.

[3] When the impact of the 12-week programme was modelled over 25 years, it was cost-saving compared with the brief intervention. Although the 52-week programme was more expensive in the within-trial analysis, when the impact was modelled over 25 years, it resulted in the greatest gain in QALYs and the greatest reduction in disease incidence.

[4] Reductions seen in the 52-week programme participants at 12 months are larger than those seen at the same timepoint in the intensive lifestyle intervention arm of the Diabetes Prevention Programme (DPP), whose participants were similar to those in the current study in baseline BMI, HbA1c and glucose and had similar weight loss at 12 months, but achieved at a fraction of the cost. Notwithstanding gradual weight regain and increase in associated risk factors observed over 15 years follow-up, DPP achieved a 27% reduction in the cumulative incidence of diabetes in the lifestyle intervention relative to the control group.

[5] Ahern A et al (2011) Weight Watchers on prescription: An observational study of weight change among adults referred to Weight Watchers by the NHS, BMC Public Health, 11, 434.