Appendices

What is a Themed Review?

Themed Reviews are narrative reviews of NIHR-funded research. They provide an overview of existing NIHR evidence, with the aim of illuminating and informing discussions on practice. Themed Reviews are one way for the NIHR to inspire the sharing of research evidence and ideas, and to promote evidence-based practice.

This review identified 143 research studies relevant to local authorities on tackling obesity. A wide array of interventions, settings, and study types were considered; some of the research is in emerging fields. Ongoing research that the NIHR has recently funded is also highlighted, since the upcoming results could help address the current gaps in the evidence base.

The Themed Review drew on the expertise of a group of practitioners, researchers and public members. Additional insight was provided by conversations with a range of staff from local councils and other key stakeholders. Insights from these exchanges provided valuable direction on the context, framing, and sense-making of the review.

Review scope

Projects in the NIHR portfolio relating to obesity and public health were screened. Projects were identified by the NIHR Centre for Business Intelligence (using definitions previously agreed for coding and classification purposes). Supplementary searches for NIHR-funded papers were performed using Dimensions.

The studies included assessed ways to tackle obesity through individual, population, community and environmental interventions, provided they were of potential relevance to local authorities. A broad approach was taken to identifying studies related to obesity. Projects on increasing physical activity or moving more were included even if they were not directly related to weight. Since the review aims to facilitate evidence-based decision making, exploratory, developmental, and early-stage studies were not included.

Studies were grouped into 9 themes, based on the nature of the studies in the portfolio, and to align the review to local authorities’ interests and the aspects they oversee.

Stakeholder Engagement

For this Themed Review, we consulted key stakeholders to understand the context in which NIHR research would be received, and to see how far the evidence reflected experiences within local authorities. We held meetings with groups of staff from the following organisations:

Additional information on graphic and charts

Table of included studies

Area of intervention Number of studies Percentage of total
System-wide approaches 9 6%
Weight management programmes 29 20%
Built and natural environments 12 8%
Active travel and public transport 13 9%
Active workplaces 10 7%
Preventing obesity in children and families 8 6%
Healthy schools 18 13%
Public sports and leisure services 14 10%
What people buy and eat 30 21%

Text alternative for Obesity in the UK graphic

Obesity in the UK

Scotland England Wales Northern Ireland
Percentage of adults with obesity 29% 28% 25% 27%
Percentage of children with obesity 16% 16% 13% 6%
Percentage of adults getting 5-a-day 222% 28% 25% 44%
Percentage of adults meeting physical activity guidelines 46% 61% 53% 36%
Areas of highest obesity Ayrshire and Arran The North East and the West Midlands Cwm Taf Morgannwg and Aneurin Bevan Health Board In the most deprived areas there were 32% of adults with obesity, compared with 25% in the least deprived areas

Definitions

How we calculate obesity. Body mass index (BMI) is a widely accepted measure for obesity based on weight and height. A BMI of 25 to less than 30 is classified as overweight. A BMI of 30 or more is classified as obese. A BMI of 40 or more is classified as morbidly obese.

Healthy eating guidelines. Guidelines recommend eating at least five portions of fruit or vegetables every day.

Physical activity guidelines. Adults should be active daily, doing 150 minutes of moderate-intensity exercise, 75 minutes of vigorous-intensity exercise, or a combination of both, over a week. Children and young people should take part in physical activity for an average of 60 minutes a day.

References for Obesity in the UK graphic

Information for this infographic was drawn from:
Welsh Government. National survey for Wales: Headline results April 2019-March 2020. 2020.
Public Health Wales. Child Measurement Programme for Wales 2018/19. 2021. (Figures in the infographic apply to children in reception year)
UK Parliament. House of Commons Library. Obesity Statistics. Briefing paper. Number 3336. 2021.
Public Health Wales NHS Trust. Obesity in Wales. 2019.
Department of Health Northern Ireland. Health survey NI trend tables 2019/20. 2020. (Figures relating to children in the infographic apply to those aged 2 – 15)
Department of Health Northern Ireland. ‘A fitter future for all’ – outcome framework (2015-19). 2019.
Department of Health Northern Ireland. Health survey NI first results 2020/21. 2021.
NHS Digital. Health survey for England 2019. Overweight and obesity in adults and children. 2020. (Figures relating to children in the infographic apply to those aged 2 – 15 and take an average of figures for boys and girls)
NHS Digital. National Child Measurement Programme England 2020/21 School Year. 2021.
Sport England. Active Lives adult survey report. May 2020/21. 2021.
OHID. Official Statistics. Physical activity data tool: statistical commentary. 2022.
Sport England. Active lives children and young people survey. Academic year 2020-21. 2021.
NHS Digital. Statistics on Obesity, Physical Activity and Diet, England. 2021.
Scottish Government. Diet and healthy weight: monitoring report 2020. 2020.
Scottish Government. The Scottish Health Survey 2020 edition. 2021. (Figures relating to children in the infographic apply to those aged 2 – 15)
Public Health Scotland. Physical activity overview. 2021.
PHE in association with the Welsh Government, Food Standards Scotland and the Food Standards Agency in Northern Ireland. Eatwell Guide. 2016.
DHSC. UK Chief Medical Officers’ Physical Activity Guidelines. 2019.
Department of Health Northern Ireland. Health survey NI trend tables 2019/20. 2020.

Foreword

I am delighted that this Themed Review has been undertaken. The NIHR is a well-oiled machine for commissioning research, but we sometimes lack the time and space to stand back and understand what we have learned from our various outputs. Over time, obesity research has of course encompassed diet and nutrition as well as wider interventions related to travel, the environment and physical activity. It’s a good time to step back and ask what we have learned from this body of research.

Inevitably this review is a snapshot and only part of the vast amount of evidence on obesity. However, it provides us with important pointers about where to go next. At the NIHR, we will continue dialogue with the research and policy communities to make sure that future research targets the areas likely to offer the most value in tackling this complex public health issue. Just as there is no single magic bullet to intervene in obesity, there will be no single path for research. Future approaches will need to complement other research initiatives and activities both within and outside of the NIHR.

Professor Brian Ferguson, Programme Director NIHR Public Health Research (PHR) Programme

Commentaries

“Obesity is a complex problem with a large number of different but often interlinked causes. No single measure is likely to be effective on its own in tackling obesity. To have a significant impact on obesity levels, it is clear that everybody needs to get involved. Local authorities are particularly well placed as the functions they are responsible for serve all generations in society and can directly influence people’s health. This research provides really useful information to support local authorities with implementing a whole systems and whole council approach to address obesity and promote a healthy weight.”

“Obesity prevention continues to be a major public health priority. Recognising that local authorities are uniquely positioned to work with partners and influence the local drivers of obesity, public health teams have been asked to take a whole systems approach. This themed review presents local authorities with a collation of key research findings for interventions targeting individual drivers of obesity. Going forward a step change is needed to look at interventions as part of a system and not in isolation. To support a whole systems approach and build the evidence-base, future research should consider how interventions interact with the context (a complex dynamic system) and consider how they change the system to address obesity.”

“This summary is a good starting point if you want to explore obesity research. If digging deeper, consider not just what does and doesn’t work but the ‘why’ and ‘how’. This is not an overall guide of what to do, for three reasons. First, this review only covers NIHR-funded research. Second, and more broadly, much of the research is inconclusive. For instance, it might say an intervention didn’t work, but not whether it would have worked if it was implemented slightly differently. Finally, the research that has been carried out to date does not represent all topics and types of research evenly (e.g. there is more on individuals than systems).
There is currently no definitive prescription for a multifaceted local authority approach. What does seem to be clear is that local authority action needs to take account of the ‘whole system’ and how it works (in particular the food industry), even if the local authority can only influence a part of it. This is particularly important in the food industry. Local authorities can use their own data and experience and data to help shape and contribute to future research.”

“Obesity is a complex public health challenge. Drawing on complex adaptive systems has enabled detailed descriptions of the determinants of obesity and their interactions. Views differ on what whole systems approaches to tackling obesity mean but the scope of such systems extend beyond single entities. There is a risk that ‘whole systems’ is understood to imply ‘multiple concurrent interventions at various levels and across the entire life course’. This is neither achievable, even with additional resources, nor sufficiently cognisant of the role of simple rules (small changes) in a complex system in producing transformational impact. Future research has to further our understanding of those small changes in sufficient practical detail if we are to achieve sustained impact in terms of a left-ward shift of the dial on the population’s weighing scale. This review is a real welcome step in the right direction but it signals the need for more work.”

“Health & Wellbeing Boards have (since the Health & Social Care Act 2012) been the formal committee of a local authority charged with promoting greater integration and partnership between bodies from the NHS, public health, the voluntary sector and local government. With the introduction of Integrated Care Systems (ICSs) as part of the 2022 Health & Care Bill, system-wide approaches between local health, local authority and voluntary and community sector partners will also be in the remit of integrated care partnerships both at ICS (sub-regional) level and more local Place-based partnership level (at the level of a single unitary authority).

With Place-based Committees and Health & Wellbeing Boards being guided to try and adopt Shared Outcomes in the Integration and innovation White Paper, the opportunity to embrace, develop, plan and implement system-wide approaches for tackling obesity and promoting healthy weight, healthy eating and physical activity throughout the life course has never been greater, nor the need more sharply focussed in both the health and care arena, at both hospital, secondary-care, primary care, community, school and neighbourhood levels. Nor could the need for evidence-led actions be greater, to inform best-practice approaches and evidence-led programmes that have been shown to work as practical interventions.”

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