Internet Explorer is no longer supported by Microsoft. To browse the NIHR site please use a modern, secure browser like Google Chrome, Mozilla Firefox, or Microsoft Edge.

Policy Research Programme Policy Research Unit - Healthy Weight


Published: 09 August 2022

Version: 1.0 - August 2022

Print this document

Area of Research: Healthy Weight

Section 1: Summary of main strands/themes for research

Poor diet and excess weight are one of the leading health challenges facing the country. At present, around two-thirds of adults are above a healthy weight, and of these, half are living with obesity. Forty per cent of children leave primary school already having overweight or living with obesity; obesity is socially patterned giving rise to long-term health disparities.

Maintaining a healthy weight and eating a healthy, balanced and nutritious diet is essential to overall good health and protects against chronic disease. Having a body mass index (BMI) that is too high and/or a poor diet significant combined contribution to life years lost to ill health and disability. It is a risk factor for a range of chronic diseases, including cardiovascular, liver and respiratory disease, type 2 diabetes, at least 13 kinds of cancer; and can impact negatively on mental health.

Research is required to inform all stages of policy related to good nutrition, healthy diets and healthier weights. Expertise within the Healthy Weight Policy Research Unit (HW-PRU) should be able to respond to policy research needs covering a broad range of areas, including but not limited to:

Health Disparities – we expect all research funded to consider health disparities within their focus. This includes but is not limited to age, gender, ethnicity, geography and deprivation. We require evidence to better understand health disparities to support targeted interventions for those most at risk of poor outcomes related to suboptimal diet, overweight and obesity, working in partnership with main agents of change including industry, local government, other community actors and the health service.

The Food System – the impact of the obesogenic environment on individuals’ diet leading to overconsumption of food and drinks high in saturated fat, salt or sugar (HFSS), and excess consumption of calories continues to be important. We have particular interest in the out of home sector, including delivery platforms and the take-away sector. In particular, the impact of the food industry on what people purchase and consume is irrefutable. Research on commercial (e.g., profit driven business models) and non-commercial (e.g., labelling) incentives to drive industry to ensure healthier food options are accessible, affordable, sustainable and promoted is of interest. A wide range of businesses are of interest from large organisations through to small and medium enterprises, which are currently out of scope of current regulatory changes. There are cross-government levers to support this so a systems approach will be key.

Prevention – supporting the population to eat a healthy and balanced diet and to maintain a healthy weight and prevent overweight and obesity are priorities. Physical activity also plays a critical role in maintaining a healthier weight and good overall health. This Unit should support current Department of Health and Social Care (DHSC) policies, including but not limited to: front of pack nutritional labelling; promotions and advertising restrictions of HFSS food and drink; improving the vitamin D status of the population; and the Healthy Food Schemes (e.g., Healthy Start). It should also look at both upstream and downstream interventions across the life course, building the evidence base on longer-term effectiveness and options for targeted and universal interventions.

Adult weight management – we require analysis and evidence to develop a more holistic, supportive and fiscally sustainable approach to weight management for adults including the identification of the key elements of behaviour change interventions that are clinically and cost-effective in the longer-term, and which lead to maintained weight loss in the future.

Food Insecurity – food insecurity is of growing concern. While food poverty is linked to deprivation, we require research to understand the impact of food security on the quantity and quality of diets, any correlation with malnutrition, and consumer behaviour, and to model and consider interventions to mitigate longer-term health related outcomes.

Section 2: Details of policy context and background

The Government’s current obesity strategy was published in July 2020. This brought together the commitments from the Childhood Obesity Plan (chapters 1 and 2) and the Prevention Green Paper into a single, holistic approach to enabling everyone achieve and maintain a healthier weight.

The current priorities from this strategy include the delivery and implementation of legislation to support the creation of a healthier food environment for all. This has seen the formal introduction of calorie labelling in large businesses in the out of home sector and will see restrictions on the promotion and advertising of less healthy food come into force over the next 18 months. We are also committed to consulting on infant food and marketing.

We are also focused on driving effective industry reformulation of food to improve nutritional intake, quality of diets and to help people achieve and maintain a healthier weight. This is driven by some of our regulatory interventions, but also through voluntary reformulation programmes on sugar, salt and calories.

These interventions will support us in meeting our target to halve childhood obesity by 2030. But more action will be required to meet the challenges of the past and those of the future (e.g., cost of living). Areas of interest for the Office of Health Improvement and Disparities (OHID) in tackling obesity and improving diets include how we most effectively deliver the systems change that is needed to help everyone live healthier for longer. This includes better cross-working within government, how government (both central and local) partners effectively with other core agents of change including industry, community groups and the health service. Considering the challenges of cost of living, it also includes how government, and its partners, enable and ensure access to a greater range of affordable, healthy options for everyone.

Section 3: Justification for research topics (should include areas of expertise required)

Research is needed to support the full policy cycle from improving our understanding of policy problems and generating options for policy development, through to piloting/testing and full programme evaluation, where possible.

Types of research expertise and resource required includes access to and analysis of large datasets; evidence reviews; mixed methodology primary research skills, including experimental design; modelling; health economics; support for evaluation from advice to underpinning research and smaller-scale pilots; behavioural science; and horizon scanning techniques.

Section 4: Other related research activity of which the Unit will need to be aware

Applicants should consider how they would work with other PRUs that might have food, nutrition or healthy weight related research within their remit, such as PRUs on Public HealthBehavioural Science and Policy Innovation and Evaluation.

The NIHR has a large-scale programme of research on healthy weight, diet and nutrition, food systems and wider public health research of which applicants should be aware. This includes research which captures the wider determinants of health. The UK Prevention Research Partnership have also invested in research relevant to the themes set out above, for example SPECTRUM and GENIUS.