A blueprint for halving obesity

A case study

At a glance

In the last 30 years, the number of adults living with obesity has doubled, with numbers projected to rise even further in the years to come.

Over this period, we’ve seen a succession of government initiatives focused on tackling the issue. But too often these focused on actions that aren't very effective, or just weren't sufficient to the scale of the challenge.

We set out to provide policymakers with a clear, evidence-based roadmap for effective intervention. We created a toolkit that synthesises evidence on effective interventions and presents a range of cost-effective policy options.

Since its launch, our blueprint for halving obesity has become the go-to guide on obesity for government officials. One of the policies it evaluated as being high impact while low cost to implement - based on previous work by Nesta - directly influenced the UK government's announcement of a new healthy food standard. This is a measure we estimate could reduce obesity by around a fifth, helping over three million people achieve a healthier weight.

The challenge

Rising rates of obesity in the UK are a major public health concern. Obesity is linked to significant negative health conditions, including type 2 diabetes, several types of cancer, heart disease and stroke. A 2025 study estimated the annual cost of adult obesity and overweight to the UK at around £126 billion, while the NHS spends around £12 billion a year on treating obesity-related ill health.

Over recent decades, government initiatives have fallen short of tackling the scale of the problem, focusing on individual willpower rather than system-wide change.

At Nesta, we want to halve the prevalence of obesity by 2030, bringing us back to rates last seen in the 1990s. Achieving such a reduction is an ambitious goal and will take concerted effort from multiple actors across the food and health systems. But if we take the right action at the right scale, it can be achieved.

What we did

To provide policymakers with a clear path forward, we engaged scientific experts and policymakers to calculate the relative impact of different interventions to reduce obesity.

We worked with a panel of experts to synthesise peer-reviewed evidence and reach a consensus about the relative impact and cost of these interventions.

And finally, we consulted with civil servants working across central, devolved and local governments to test the usability of our product: an online toolkit that enabled users to assess the cost and impact of different policies aimed at reducing obesity in the UK.

We wanted policymakers to feel confident that they could consider all of the best evidence when making decisions. Nesta’s project delivered a toolkit that presents this much-needed information in an accessible way.

What we found out

Our analysis showed that there are several feasible and cost-effective routes to halving obesity. Some will require deeper pockets, and others greater political will.

Our analysis made clear that policies focused on individual behavioural change (such as media campaigns, information provision or education in schools) are not sufficient. While these could form small parts of a wider strategy, we will not get where we need to be on obesity – or indeed the UK government’s current commitment to reduce inequalities in healthy life expectancy – without much greater ambition.

We also found that treatment alone (in the form of weight-loss medications) would be a prohibitively expensive route to halving obesity.

To make real change in the real world, we found that a package of policies is needed, which includes regulation to shift incentives for big food businesses towards healthier sales, increased treatment for those most in need, and implementation of existing commitments on advertising restrictions.

To illustrate how the toolkit could be used by policymakers designing an obesity reduction strategy, we estimated the total cost and impact of four potential policy packages, two of which would halve the current rate of obesity.

What we found out

Our analysis showed that there are several feasible and cost-effective routes to halving obesity. Some will require deeper pockets, and others greater political will.

Our analysis made clear that policies focused on individual behavioural change (such as media campaigns, information provision or education in schools) are not sufficient. While these could form small parts of a wider strategy, we will not get where we need to be on obesity – or indeed the UK government’s current commitment to reduce inequalities in healthy life expectancy – without much greater ambition.

We also found that treatment alone (in the form of weight-loss medications) would be a prohibitively expensive route to halving obesity.

To make real change in the real world, we found that a package of policies is needed, which includes regulation to shift incentives for big food businesses towards healthier sales, increased treatment for those most in need, and implementation of existing commitments on advertising restrictions.

To illustrate how the toolkit could be used by policymakers designing an obesity reduction strategy, we estimated the total cost and impact of four potential policy packages, two of which would halve the current rate of obesity.

What was the outcome?

Since its launch in November 2024, Nesta’s Blueprint for halving obesity has become a go-to obesity policy guide. It’s been widely used, with praise from government officials from Alan Milburn to Lord Gus O’Donnell calling it “compelling,” “phenomenal,” and “required reading”. We continue to review the latest evidence and update the toolkit regularly to reflect this.

Our policy recommendation on health targets for retailers - based on previous work by Nesta - was included in the government’s 10 Year Health plan as part of the healthy food standard, which will require food businesses, including supermarkets, to sell healthier food. The Right Honourable Wes Streeting MP, Secretary of State for Health and Social Care, confirmed that “the genesis of the supermarket health targets policy was an idea from Nesta.”

Our analysis has found that if the policy is successfully implemented, it could make a huge difference to our nation’s health over time.

Nesta’s own modelling suggests this policy could reduce obesity by around a fifth over time, with the right level of ambition and incentives, helping more than three million people move to a healthier weight.

What we learnt

Assess the evidence at pace

Rigorous synthesis of academic research can take several years. But given Nesta’s role as an impact-focused innovation agency, the method for synthesising evidence needed to be adapted. Policy research needs to happen on a more rapid timeframe to respond to changing political landscapes. To achieve this, tapping into a panel of experts early on was key.

Working at pace meant we were able to deliver the toolkit at an opportune moment, while still utilising rigorous research and the collective knowledge of experts.

Identify your most important metric

There have been thousands of trials published about the most effective interventions for weight loss, but all are tested against different metrics, making it very difficult to recognise which one is most effective.

The blueprint toolkit uses high-quality evidence produced by academics but models the impact of interventions against a single metric: the impact on national obesity rates. Whilst assumptions were required to achieve this, it was much more useful to be able to compare policies against the same metric to inform evidence-based decision-making.

A best guess is better than nothing

In a trial, an intervention might have one impact, but in the real world, there are many more variables, and lots of assumptions need to be made to model the impact of policy change.

This means we’re less confident about the exact outcome for an intervention that is complicated to deliver and hard to monitor. But at a policy research level, we believe that having a partial approximation of the outcome is good enough if that indicates a sufficient impact towards a policy goal.

Show the path to scale

To illustrate the potential for impact, we modelled different policy packages and demonstrated how they could lead to our ambitious goal of halving obesity. This approach helped make a seemingly intractable problem feel solvable and provided a clear roadmap for change.