Following weight loss, many people find it challenging to sustain their new weight, with about 80% regaining the weight lost within one year. There is growing evidence that interventions grounded in acceptance and commitment therapy (ACT) may provide more effective and compassionate support for long-term weight management than standard approaches.
The SWiM programme is a five-year, NIHR-funded research initiative led by Professor Amy Ahern from the Prevention of Diabetes and Related Metabolic Disorders in High-Risk Groups programme at the MRC Epidemiology Unit, University of Cambridge.
Building on findings from the SWiM feasibility study and the SWiM-COVID study, SWiM aims to address the challenge of weight regain, a common issue following initial weight loss interventions.
Using a guided self-help approach grounded in ACT, the SWiM intervention is designed to help individuals overcome the psychological barriers to long-term weight maintenance.
We will conduct a large-scale randomised controlled trial with 1,840 participants who have completed a behavioural weight loss programme. Over the five years, we will evaluate SWiM’s effectiveness, equity, and cost-effectiveness, measuring outcomes such as weight, mental health, and wellbeing at 6, 12, and 24 months.
SWiM involves working closely with people from diverse backgrounds, including those from underserved communities, offering access to web- and paper-based self-help materials, and remote support from trained coaches. The programme will also explore tailored adaptations for individuals who have undergone weight loss through medications or bariatric surgery.
This research will help inform NHS and government decisions on scaling up SWiM across the country, with the aim of enhancing weight maintenance support in health services nationwide.
If you’ve recently completed a behavioural weight loss programme and have been directed here because your provider thinks this study may be a good fit for you, we’d be delighted to hear from you.
You can find out more and register your interest at: https://redcap.link/swim2eoi.
Professor Amy Ahern
Professor Amy Ahern is a Research Professor and Programme Leader at the MRC Epidemiology Unit, University of Cambridge, leading the Prevention in High Risk Groups research programme. Her work focuses on developing and evaluating scalable behavioural interventions for obesity and diabetes prevention, with an emphasis on eating behaviour, long-term effectiveness, and mental and physical health outcomes.
Dr Sarah Bates
Dr Sarah Bates is a Research Fellow at the University of Sheffield and a public health economic modeller with a background in psychology. Her work focuses on estimating the long-term impacts and cost-effectiveness of weight management and mental health interventions.
Dr Clare Boothby
Dr Clare Boothby is a Data Scientist at the MRC Epidemiology Unit, University of Cambridge, responsible for data management within the Prevention in High Risk Groups programme. She has a background in physics and scientific publishing, and supports data collection for several of the Unit’s major studies.
Professor Alan Brennan
Professor Alan Brennan is Professor of Health Economics and Decision Modelling at the University of Sheffield, where he leads a large research group focused on mathematical modelling in health and healthcare. His work includes evaluating the cost-effectiveness of policies related to food, obesity, diabetes, and cardiovascular disease prevention.
Dr Penny Breeze
Dr Penny Breeze is a Senior Research Fellow at the Sheffield Centre for Health and Related Research, University of Sheffield. She is a health economist specialising in decision modelling, with a focus on evaluating the long-term cost-effectiveness of obesity interventions
Mr Ken Clare
Ken Clare is a UK-based obesity advocate, former nurse, and patient voice leader with lived experience of severe obesity, serving as Executive Director of UKCPO and Lead for PPIE at the Obesity Institute, Leeds Beckett University. He founded WLSInfo in 2003, co-founded the Obesity Voices Hub, and is a council member of BOMSS, with a strong focus on patient-led support and advocacy in obesity care and research.
Filly Liuni Cox
Filly Liuni Cox is Senior Study Coordination Assistant on the SWiM study and has previously worked at MRC Human Nutrition Research and in a global pharmaceutical contract research organisation. She holds a BSc in Human Nutrition from the University of Nottingham and brings experience in clinical coordination, alongside a passion for travel and baking.
Professor Robbie Duschinsky
Professor Robbie Duschinsky is Professor of Social Science & Health in the Department of Public Health and Primary Care at the University of Cambridge, and a Fellow and Director of Studies at Sidney Sussex College. His research focuses on the social and ethical dimensions of health and healthcare.
Dr Tamla Evans
Dr Tamla Evans is a Health Psychologist at the University of Cambridge specialising in the development and evaluation of behavioural interventions for long-term conditions such as obesity and type 2 diabetes. Her research focuses on the psychological determinants of health and illness.
Professor Simon Griffin
Professor Simon Griffin is Professor of General Practice at the University of Cambridge and a GP at Lensfield Medical Practice. His research focuses on the prevention and management of chronic conditions in primary care.
Dr Laura Gray
Dr Laura Gray is a Senior Research Fellow and health econometrician at the University of Sheffield. Her research focuses on obesity, its measurement, and its development over time in individuals and populations. Within the SWiM study, she is leading an econometric analysis exploring the dynamic, bi-directional relationship between obesity and mental health.
Professor Andrew Hill
Professor Andrew Hill is Professor of Medical Psychology at the University of Leeds, with a long-standing research focus on appetite, body image, disordered eating, and obesity. He teaches undergraduate medical students as well as psychiatrists and clinical psychologists in training.
Dr Carly Hughes
Dr Carly Hughes is a former NHS GP with over 30 years’ experience and an obesity specialist who led an award-winning primary care-based weight management service. Now retired from clinical practice, she continues as a researcher at the MRC Epidemiology Unit, with interests in weight loss maintenance, post-bariatric care, and models of primary care delivery.
Dr Julia Mueller
Dr Julia Mueller is an Assistant Professor in the MRC Epidemiology Unit, University of Cambridge, and co-investigator on the SWiM programme. Her research explores how psychological approaches can support the treatment and prevention of obesity.
Mrs Hazel Patel
Ms Hazel Patel is a Public Contributor with over six years of experience in patient and public involvement in health research, with a particular interest in ensuring studies reflect diverse community perspectives. She is passionate about inclusion, practical impact, and building trust between research and the public, contributing to studies nationally.
Mr Stephen Sharp
Mr Stephen Sharp leads the Statistics and Data Science team at the MRC Epidemiology Unit, University of Cambridge, and has over 15 years’ experience in medical statistics. He has worked in both academic and industry settings and served on a NICE Technology Appraisal Committee for over a decade.
Dr Marie Spreckley
Dr Marie Spreckley is the Research Programme Manager for the SWiM study at the MRC Epidemiology Unit, University of Cambridge, where she leads on programme operations, Patient and Public Involvement, and stakeholder engagement. She is a registered nutritionist with a PhD in sustainable weight loss, and her research focuses on behavioural strategies to support long-term weight maintenance and improve health outcomes.
Professor Jonathan Valabhji
Professor Jonathan Valabhji is Clinical Chair in Medicine at Imperial College London and Honorary Consultant Diabetologist at Chelsea & Westminster Hospital NHS Foundation Trust. He served as National Clinical Director for Diabetes and Obesity at NHS England (2013–2023), where he led the development of national programmes including the NHS Diabetes Prevention Programme.
Jenny Woolston
Jenny Woolston is the Study Coordinator for the SWiM study at the MRC Epidemiology Unit, University of Cambridge, and has worked on a range of studies within the Prevention in High Risk Groups programme. She has a background in clinical research and trial management, and holds an MSc in Clinical Trials from the London School of Hygiene and Tropical Medicine.
Please see our Data Sharing pages.
We would like to thank Dr Becky Richards, Dr Beckie Jones, and Ms Fiona Whittle for their valuable contributions to the development of the SWiM study. Their input helped shape the foundation of the programme and is greatly appreciated.
