This issue brief reviews the drivers (long term and short term), their impacts, and indicators of food and nutrition security (FNS). The FAO defined food and nutrition security as a situation “when all people, at all times, have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life” (FAO 2006). This definition of FNS highlights four dimensions of food security: food availability, access to food, the utilization of food, and the stability of these three dimensions. FNS is clearly an individual-specific outcome, but many of its indicators and of its drivers (causes) are measured at macro level and can only serve as proxies for FNS (individual) outcomes. Availability, accessibility and stability reflect the issue of the adequacy of dietary intake and a number of existing indicators can be used to approximate it, like per capita net calories available in a given country, share of food in total household expenditures, or per capita food supply variability. Individual level indicators like stunting and over- and underweight can cover the utilization dimension of FNS.