In Rome on June 2014 a report by the High Level Panel of Experts on Food Security and Nutrition (HLPE) approved by the HLPE Steering Committee came public. In fact HLPE was created in 2010 to provide the United Nations’ Committee on World Food Security (CFS) with evidence-based and policy-oriented analysis to underpin policy debates and policy formulation. The HLPE works on topics identified by the CFS. This is the eighth HLPE report to date. This policy-oriented report 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. Successful reduction of food losses and waste will save resources and has the potential to improve food security and nutrition, goals shared with the Zero Hunger Challenge and the post-2015 sustainable development agenda. Again the food losses and waste have been approached by two different angles: either from a waste perspective, with the associated environmental concerns, or from a food perspective, with the associated food security concerns. This duality of approaches has often led to confusions on the definition and scope of food losses and waste, contributing to unreliability and lack of clarity of data. The report also depicted Scope and extent of food losses and waste (FLW), impacts of FLW on food security and nutrition and on the sustainability of food systems, organizing the description of causes of FLW like micro, macro causes and the growing set of initiatives towards coordinated actions to tackle FLW. The HLPE recommends that States and international organizations better integrate food chains and food systems perspectives in any food security and nutrition strategy or action. Reduction of FLW should be systematically considered and assessed as a potential means to improve agricultural and food systems efficiency and sustainability towards improved food security and nutrition. Direct and indirect causes of FLW in a given system should be analyzed to identify hotspots where it would be most efficient to act.