Food systems are expected to provide food security and nutrition, to contribute to the livelihoods of millions, and to do so in an environmentally sustainable way. The broad outlines of these challenges are clear, and in many cases evidence exists on how better policies can improve the performance of food systems. But there are considerable gaps in data and evidence. This paper provides a panoramic overview of different types of evidence gaps on food systems and their causes, and makes the case that better evidence is needed to enable better policies. At the same time, evidence will never be complete. Policy makers and the research community thus need to adopt a pragmatic approach, focusing on where better evidence can make the biggest difference.
