Introduction
The Food and Agriculture Organization of the United Nations (FAO) defines food security as a ‘situation that exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life’ (FAO 2002). This definition comprises the four key dimensions of food security: availability, stability, utilisation and access. The first dimension relates to the availability of sufficient food, that is, to the overall ability of the agricultural system to meet demand for food. The second dimension, stability, relates to individuals who are at high risk of temporarily or permanently losing their access to the resources needed to consume adequate amounts of food, either because these individuals cannot insure ex ante against income shocks or they lack the resources to smooth consumption ex post or both. An important cause of unstable access to food is climate variability.
The third dimension, utilisation, encompasses all aspects of food safety and quality of nutrition. Its subdimensions are therefore related to health, including the sanitary conditions along the entire food chain. It is not enough that someone is getting what appears to be an adequate quantity of food if that person is unable to use the food properly (Schmidhuber and Tubiello 2007).
The fourth dimension, access, covers access by individuals to adequate resources (or entitlements) to acquire appropriate foods for a nutritious diet.