Problem
More than one in ten children aged 5 to 19 in southern Europe are living with obesity. In Greece, Malta and Italy, more than one in three children are overweight. The health consequences last a lifetime: obesity in childhood raises the risk of serious diseases in adulthood and places a growing burden on health services and economies across Europe.
Simulation modelling is now standard practice for infectious diseases. It is not yet standard for long-term conditions such as obesity and diabetes. That gap has a cost.
Science
We built Health-GPS, a policy simulation tool that creates a virtual population representative of a real country and tracks the life of each person in it from birth to death. We developed the model at the Centre for Health Economics & Policy Innovation (CHEPI) at ³Ô¹ÏºÚÁÏ as part of a multi-million-pound European project aimed at influencing childhood obesity policy. We drew on national dietary surveys, demographic records and disease registries across European countries to build a picture of how risk factors such as diet, physical activity, and body weight change over time, and how these risk factors interact with conditions including diabetes, hypertension and certain cancers.
We estimate the impact of new health policies by running two simulations side by side: a baseline run, in which no policy is applied, and an intervention run, in which a policy such as food labelling or a healthy eating programme is introduced. The difference between the two shows the effect of the policy. Health-GPS is open-source and designed to run on standard computing platforms, enabling researchers and policy teams anywhere can use it.
Outcome
Our results show that Health-GPS can estimate the impact of health interventions on a population, tracking changes in body mass index (BMI), disease rates, life expectancy and healthcare costs over time. The model was a central output of STOP (Science and Technology in childhood Obesity Policy), a Horizon 2020-funded research programme that brought together 31 organisations across 16 countries and produced over 50 scientific publications, including two special issues in Obesity Reviews and PLoS Medicine.
Health-GPS is now being used in active research projects at ³Ô¹ÏºÚÁÏ, including studies on the health effects of taxes on ultra-processed food, foods high in fat, salt and sugar in India and the UK, and work to assess the impact of diet on the incidence of chronic diseases across six EU countries.
Change
Health-GPS changed how governments across Europe and beyond can make decisions about childhood obesity and test whether their policies will work. It gives policymakers a way to compare the likely effects of different interventions before committing public money and to identify which communities stand to benefit most.
We call on health ministries, national public health agencies and international bodies to treat simulation modelling as a standard part of the policy development process for long-term conditions. Health-GPS is open-source, designed to be expanded, and already in active use across multiple countries.
Professor Franco Sassi, Dr Jingmin Zhu, Dr Jack Olney; Centre for Health Economics & Policy Innovation (CHEPI), ³Ô¹ÏºÚÁÏ