Joseph V. Spadaro

Health effects of adopting low greenhouse gas emission diets in the UK

Objective Dietary changes which improve health are also likely to be beneficial for the environment by reducing emissions of greenhouse gases (GHG). However, previous analyses have not accounted for the potential acceptability of low GHG diets to the general public. This study attempted to quantify the health effects associated with adopting low GHG emission diets in the UK. Design Epidemiological modelling study. Setting UK. Participants UK population. Intervention Adoption of diets optimised to achieve the WHO nutritional recommendations and reduce GHG emissions while remaining as close as possible to existing dietary patterns. Main outcome Changes in years of life lost due to coronary heart disease, stroke, several cancers and type II diabetes, quantified using life tables. Results If the average UK dietary intake were optimised to comply with the WHO recommendations, we estimate an incidental reduction of 17% in GHG emissions. Such a dietary pattern would be broadly similar to the current UK average. Our model suggests that it would save almost 7 million years of life lost prematurely in the UK over the next 30 years and increase average life expectancy by over 8 months. Diets that result in additional GHG emission reductions could achieve further net health benefits. For emission reductions greater than 40%, improvements in some health outcomes may decrease and acceptability will diminish. Conclusions There are large potential benefits to health from adopting diets with lower associated GHG emissions in the UK. Most of these benefits can be achieved without drastic changes to existing dietary patterns. However, to reduce emissions by more than 40%, major dietary changes that limit both acceptability and the benefits to health are required.

What Role Can Taxes and Subsidies Play in Changing Diets

The study examines the use of fiscal instruments to achieve a healthier diet while reducing CO2 emissions. The methodology is to minimize the deadweight losses in attaining a healthy diet. Given that the shift should not impose a large burden on the consumer, the analysis is conducted with a system of taxes and subsidies - a bonus-malus framework. The model generates heavy subsidies on carbohydrates and heavy taxes on red meats, which would be politically unacceptable. A more plausible goal may be to aim to close the gap between the current diet and a healthier one by 20-25 percent.