Food security is defined as the availability of and accessibility to sufficient food at all times for all people. Sufficient food refers to both quantity and quality needed for good health. Food security is one of the major concerns of developing countries (especially in Africa south of the Sahara) despite the efforts to improve food situation in the world. Food security can be viewed at different spatial levels: global, national, household, and individual. Increasing attention is made at household and individual level because achieving food security at both global and national levels does not necessarily mean food availability and accessibility at household level.

Household food security can be measured using several indicators. The basic indicator is Adult Equivalent (AE) kilocalories per day (See Measuring Food Security in a Survey Round). In addition, several other possible indicators can be used. (See Food Security Indicators). The best practice is to collect these indicators once in every DSS round; this allows longitudinal food security monitoring (see Sample Food Security Form and Land Asset Form).