This book provides a comprehensive overview of key aspects of food insecurity, including definitional and conceptual issues, information systems and data sources, indicators, and policies. The aim is to equip readers with a sound understanding of the subject that will assist in the recognition of food insecurity and the design of suitable responses. The early chapters discuss the evolution and limitations of the concept and provide a set of conceptual frameworks for the analysis of food security. Systems used to collect data and their evolution over time are then explained, and the most commonly adopted indicators for monitoring food security are presented. Approaches to food security are then thoroughly reviewed decade by decade. Specific attention is paid to the food insecurity challenge in the new millennium, focusing particularly on recent food crises and institutional and policy-related consequences. Finally, the specific terminology of food aid and assistance is examined, with discussion of the instruments recently adopted in the food aid system. This book will be an informative and stimulating resource for both students and professionals.