Providing affordable access to enough healthy and safe food for an ever-more-affluent and growing world population has become more challenging in the face of climate change, rising income inequality and a more uncertain global trade environment. Agriculture is expected to contribute more, but is under pressure in both high-income and developing countries to do so more sustainably and inclusively. This paper reviews the roles of food policy in this changing setting. It begins by revisiting the case for keeping food markets open to international trade, investment and technology transfer, and concludes that openness is even more important, especially for developing countries, as the climate becomes warmer and more volatile. It then summarizes trade-related food policy developments globally in the 50 years prior to the global financial crisis, and in the price-spike periods since then. The current situation is calling for more action - including from agriculture - to mitigate climate change and biodiversity loss. The scope for re-purposing food policies to better meet these demands is then assessed. It proposes some alternatives to current measures that could better achieve national societal objectives while simultaneously benefitting the rest of the world in terms of easing natural resource and environmental stresses and reducing national and global poverty, food and nutrition insecurity, and inequalities in income, wealth and health. The review concludes by noting areas where further research could facilitate such transformations in food policies.