This policy-oriented report from the High Level Panel of Experts on Food Security and Nutrition (HLPE) presents a synthesis of existing evidence about the causes of food losses and waste and suggests action to reduce them in order to improve food and nutrition security and the sustainability of food systems. The aim of this report, given the diversity of contexts, is to help all concerned actors to reduce food losses and waste by identifying the causes and potential solutions that may be implemented, alone or in a coordinated way, by the relevant actors in the food system, including the public and private sectors, civil society, individual producers, wholesalers, retailers and consumers.