Modelling the health co-benefits of sustainable diets in the UK, France, Finland, Italy and Sweden

Background/Objectives It is not known if diets lower in greenhouse gas (GHG) emissions are also healthier. We evaluated the population health implications of changing to more sustainable diets in the UK, France, Finland, Italy and Sweden. Subjects/Methods We developed a life table model to simulate mortality and morbidity from diet-related diseases over the lifetime of the current population. Populating the model with locally available data for each country, we simulated the impact of country-specific dietary scenarios that had been optimised to meet dietary recommendations and reduce GHG emissions. Outcome measures included a change in disease-specific deaths, life expectancy and disability-adjusted life years (DALYs). Results Diets that meet nutritional recommendations lead to substantial improvements in population health, ranging from 0.19 (95% uncertainty interval: 0.18-0.21) DALYs per person in Italy up to 0.89 (0.80-0.98) DALYs per person in Finland. Simultaneously reducing GHG emissions does not reduce the size of this impact, and in some cases produces additional health benefits. If sustainable diets can be maintained throughout adulthood, life expectancy would increase by between 2.3 (1.6-3.2) and 6.8 (5.5-8.5) months by country. However, results are sensitive to assumptions about how quickly changes in diet can influence disease, and future trends in disease. Conclusions Modelling the health impact of diets that are both nutritional and low in GHG emissions shows the potential for significant co-benefits in health and sustainability from dietary changes. Future work is needed to find effective interventions to deliver healthy sustainable diets.