RESUMO
The objective of the present paper is to draw lessons from policy development on sustainable diets. It considers the emergence of sustainable diets as a policy issue and reviews the environmental challenge to nutrition science as to what a 'good' diet is for contemporary policy. It explores the variations in how sustainable diets have been approached by policy-makers. The paper considers how international United Nations and European Union (EU) policy engagement now centres on the 2015 Sustainable Development Goals and Paris Climate Change Accord, which require changes across food systems. The paper outlines national sustainable diet policy in various countries: Australia, Brazil, France, the Netherlands, Qatar, Sweden, UK and USA. While no overarching common framework for sustainable diets has appeared, a policy typology of lessons for sustainable diets is proposed, differentiating (a) orientation and focus, (b) engagement styles and (c) modes of leadership. The paper considers the particularly tortuous rise and fall of UK governmental interest in sustainable diet advice. Initial engagement in the 2000s turned to disengagement in the 2010s, yet some advice has emerged. The 2016 referendum to leave the EU has created a new period of policy uncertainty for the UK food system. This might marginalise attempts to generate sustainable diet advice, but could also be an opportunity for sustainable diets to be a goal for a sustainable UK food system. The role of nutritionists and other food science professions will be significant in this period of policy flux.