Food security is not just a food policy issue. What, when, where and how much people eat is influenced by a complex mix of factors at the societal and individual levels. These influences operate both directly through the food system and indirectly through political, economic, social, and cultural pathways - peoples' dietary behaviours are a response to the broader daily living conditions in which they are born, live, learn, work and age. In this paper we propose that to address food insecurity and diet-related death and disease, policy must tackle the systemic problems that generate poor nutrition in all its forms, and reflect how our food systems are making people sick. This has implications for economic, agriculture, food, social and health policy at the global, regional, national and local levels.