London, UK - More than 340,000 adults living with severe obesity in England will lose around 20kg of weight as a result of the NHS rolling out tirzepatide (also known as Mounjaro), according to new analysis by research foundation Nesta. Taken together this amounts to around 7 million kilograms of weight lost over five years for those at highest risk.

The rollout will initially target those most in need - adults with a BMI of 40 and above who face the highest health risks. This represents around one in five of the 1.5 million people in England living with severe obesity.

The analysis estimates the policy will deliver savings and benefits valued at around £10 billion over 5 years while costing around £1.6 billion to implement. Around a third of the savings will be ‘cashable’ - through, for example, fewer treatments for heart failure and other diseases associated with obesity.

For individuals, the effect will be transformative. For example, on average a person in the most severe class of obesity weighs around 122 kilograms. After treatment, they will lose around 23kg - moving them to a healthier weight with significant health and quality of life improvements.

While life-changing for recipients, the programme addresses just a fraction of England's obesity challenge. Around 13 million people are living with obesity in England, a major public health challenge that leads to early deaths, avoidable health problems and a less healthy workforce.

This new analysis supports previous Nesta research which shows that while obesity drugs are an excellent solution for treating very high-risk groups, it is too expensive to rely on drugs alone.

Hugo Harper, director of health at Nesta said: “The planned NHS rollout of weight-loss drugs looks to be a game-changer for people living with the most severe obesity. For those who get access to the drugs it will be life changing. But it also shows how much more we need to do. This is ultimately helping one in 40 of the 13 million people living with obesity. It is simply not affordable to treat our way out of the problem. We need both treatment and prevention - making our food healthier so fewer people need the drugs in the first place."

In its blueprint to halve obesity, first published in 2024, Nesta set out the first fully-costed and evidence-based route to reduce obesity in the UK to rates last seen in the 90s. It recommended a package of treatment and prevention policies with the objective of quickly treating those most in need while also using policy to improve the healthiness of food. The evidence assessment tool informed the development of the UK government’s 10-year Health Plan for England and contributed to the UK government adopting the Healthy Food Standard.

Obesity is one of the themes at this year’s Policy Live event today (11 September), run by Nesta, in which keynote speaker Secretary of State for Health and Social Care Wes Streeting will speak about his mission to reduce obesity and the plan to introduce a healthy food standard for large food businesses.

Notes to editors

1. For more information on the analysis or to speak to one of the experts involved, please contact Kieran Lowe, Media Manager, on 020 7438 2576 or [email protected]. Spokespeople are available for broadcast interviews.
2. The numbers in the analysis are based on 580,000 being offered treatment, with an estimated 70% (406,000) accepting. Within this group, around 344,000 will experience significant weight loss (after accounting for around 15% dropping out of the treatment).
3. The impact of the policy in terms of savings and benefits is calculated using Frontier Economics’ cost of obesity work (commissioned for the Tony Blair Institute).
   1. Around a third of the £10 billion savings are cashable gains, eg, future costs that are avoided (for example, through fewer people needing treatment for cardiovascular disease and other comorbidities)
   2. The remaining two thirds are positive but not directly cashable, eg, through people feeling healthier with improved quality of life
4. The likely cost-effectiveness of this rolling out tirzepatide to those most in need in England is within the range that NICE considers an acceptable use of NHS resources.
5. National Institute for Health and Care Excellence (NICE) guidance ‘Tirzepatide for managing overweight and obesity’: https://www.nice.org.uk/guidance/ta1026
6. NHS England Implementation Proposal: https://www.nice.org.uk/guidance/ta1026/documents/supporting-documentation-7

About Nesta

Nesta is an independent think tank focused on solving society’s biggest challenges.

Nesta conducts experiments with public and private organisations, builds and invests in early-stage ventures, and shapes policy.

Our three missions are to give every child a fair start, help people live healthy lives, and create a sustainable future where the economy works for both people and the planet.

For over 20 years, Nesta has worked to support, encourage and inspire innovation. Harnessing the rigour of science and the creativity of design, we design, test and scale solutions to change millions of lives for the better. Find out more at nesta.org.uk