1. Introduction
Since the seventies, the concept of food security has evolved from a predominant focus on supply to a multi-dimensional construct. The initial focus, reflecting the global concerns of 1974, was on the volume and stability of food supplies. Food security was defined in the 1974 World Food Summit as “availability at all times of adequate world food supplies of basic foodstuffs to sustain a steady expansion of food consumption and to offset fluctuations in production and prices” (FAO, 1996). Twenty years later, food security was defined to “exist(s) when people, at all times, have physical, social or economic access to sufficient, safe and nutritious food which meets their dietary needs and food preferences for an active and healthy life” (FAO, 1996).