Policy analysis indicates health-sensitive trade and subsidy reforms are needed in the UK to avoid adverse dietary health impacts post-Brexit.

The United Kingdom's food system will be greatly impacted by Brexit-related trade deals and policy developments-with implications for dietary risk factors and public health. Here we use an integrated economic-health modelling framework to analyse the impacts of different policy approaches to Brexit. A 'soft Brexit' that is in line with the EU-UK Trade and Cooperation Agreement increases diet-related mortality in the United Kingdom as costs for health-promoting and import-dependent foods increase and their consumption decreases. Negotiating free-trade agreements with the United States and Commonwealth countries as part of a 'global Britain' approach could triple the negative health impacts of Brexit as greater availability of energy-dense foods increases weight-related risks without meaningfully reducing dietary risks. Eliminating import tariffs on health-sensitive horticultural products could mitigate the negative health impacts of Brexit, and reforming agricultural subsidies to incentivize greater domestic horticultural production could lead to net health gains. Combining these health-sensitive approaches to trade policy and subsidy reform doubled the health gains, offering a promising approach for mitigating the detrimental impacts Brexit could have on dietary health in the United Kingdom.