Introduction Reliable food systems – which include production, value chain, market, infrastructure and consumption subsystems – are critical for human health, nutrition, well-being and equity. Producing suffi cient food of adequate quality for nine billion people by 2050 is a daunting challenge for agricultural research for development. We need access, stability and safety in food systems to achieve food security and nutrition for all. The sheer scale and urgency of our world’s food security-related mega challenges require action from many actors.