Researchers from the University of Liverpool, in collaboration with The Health Foundation, have analysed anonymised health data from 1.5 million people in England to understand how changes in everyday health behaviours - such as diet, exercise, and smoking - could influence the nation's long-term health. Their modelling shows that improving these behaviours could significantly reduce the burden of chronic illness across the population over the next two decades and beyond.
More people in England are now living with multiple long-term conditions - such as heart disease, diabetes, and cancer - and this trend is expected to continue as the population ages. This represents a serious hindrance to people's quality of life and a major challenge to the NHS. However, many chronic conditions are preventable or can be delayed, and the study makes clear that improving health behaviours and reducing health risks across the population can meaningfully reverse current trends in future illness over the next 20 years and substantially more in the longer term.
Commissioned by the Health Foundation, the study used advanced computer modelling to simulate the health of adults aged 30 and over in England from 2023 to 2043. The analysis identified some key findings:
- Obesity (measured by BMI), smoking, and high blood pressure are the three leading contributors to the growing diagnosis of major long-term illness.
- In the most optimistic scenario - where everyone in the population achieved the healthiest possible levels across eight key risk factors - the model projected over five million years of major illness could be prevented or delayed by 2043, with illness prevalence reduced by 2%, from 30% to 28%.
- This improvement is compounded by, and perhaps secondary to, a large increase in the number of people living without major illness, with 2.1 million more people alive and without major illness in 2043. This can be considered as the number of healthy lives lost by poor public health.
- Even a modest improvement in risk factors - a 10% reduction in risk factors compared to current projections - would still make a measurable difference, preventing or postponing around 1 million years lived with illness over the period and reducing prevalence by 0.3 percentage points.
- The improvements in health from such changes would not be fully realised in 2043 and health improvements would continue to grow into the 2050s and beyond.
- The benefits would not be evenly distributed: reducing obesity would have the greatest impact in the most disadvantaged communities, while lowering blood pressure would be more beneficial in wealthier areas, where life expectancy is higher.
- However, researchers observe that population health is a complex dynamic system and health means that some people may live longer with their pre-existing illness in the near term.
Dr Chris Kypridemos, Senior Lecturer in Public Health, Policy & Systems at the University of Liverpool said: "Our findings show that while healthier behaviours can reduce illness, meaningful change requires action beyond the individual. We need ambitious, society-wide policies - like improving food environments, eradicating smoking and bridging socioeconomic divides - to tackle the root causes of poor health and reduce pressure on our healthcare system."
The research underscores the need for policymakers to act now with bold public health measures, especially around reducing obesity and smoking, to ease future strain on healthcare and support healthier lives for all. The team is now conducting further analysis of real-world policy options, including those that consider both health and economic outcomes. This work will incorporate newer data -such as post-pandemic trends - to design practical, long-term strategies.
Dr Anna Head, Research Fellow, Public Health, Policy & Systems at the University of Liverpool, said: "Alongside ambitious policies to support primary prevention efforts and address the wider determinants of health and health inequalities, substantive action is also needed to support people of all ages living with long-term conditions."
Dr Toby Watt, Lead Economist at the Health Foundation said: "This research highlights the scale of the challenge: even with ambitious action, an ageing population means demand for health and care will keep rising. It shows that making improvements in risk factors like obesity, smoking, and blood pressure can make a real difference to people's lives. Effective prevention could prevent millions of cases of serious illness in the future and keeping people in work longer. This research helps us understand where to focus our efforts and shows us the scale of ambition needed. Tackling the root causes of poor health demands a clear strategy, creating environments where healthy choices are the easy choices."
The paper, 'Exploring the contribution of risk factors on major illness: a microsimulation study in England, 2023-2043' was published in Nature Communications.
