Food insecurity exists when people are undernourished as a result of the physical unavailability of food, their lack of social or economic access to adequate food, and/or inadequate food utilization. Food-insecure people are those individuals whose food intake falls below their minimum calorie (energy) requirements, as well as those who exhibit physical symptoms caused by energy and nutrient deficiencies resulting from an inadequate or unbalanced diet or from the body's inability to use food effectively because of infection or disease. An alternative view would define the concept of food insecurity as referring only to the consequence of inadequate consumption of nutritious food, considering the physiological utilization of food by the body as being within the domain of nutrition and health.

Vulnerability refers to the full range of factors that place people at risk of becoming food-insecure. The degree of vulnerability of individuals, households or groups of people is determined by their exposure to the risk factors and their ability to cope with or withstand stressful situations.

Food insecurity is a complex phenomenon, attributable to a range of factors that vary in importance across regions, countries and social groups, as well as over time (see Figure). These factors can be grouped in four clusters representing the following four areas of potential vulnerability:

• the socio-economic and political environment;
• the performance of the food economy;
• care practices;
• health and sanitation.

In order to achieve success, strategies to eliminate food insecurity have to tackle these underlying causes by combining the efforts of those who work in diverse sectors such as agriculture, nutrition, health, education, social welfare, economics, public works and the environment. At the national level, this means that different ministries or departments need to combine their complementary skills and efforts in order to design and implement integrated cross-sectoral initiatives which must interact and be coordinated at the policy level. At the international level, a range of specialized agencies and development organizations must work together as partners in a common effort.

The World Food Summit estimated that approximately 840 million people in developing countries subsist on diets that are deficient in calories.

The latest estimates indicate that roughly 826 million people are undernourished -- 792 million people in the developing world and 34 million in the developed world. Projections for 2015 and 2030 suggest that the number of undernourished in the developing world should fall to around 580 million. This still lies far short of the World Food Summit goal of reducing the number to 400 million. That goal will not be reached until 2030 according to current projections.

Undernourishment around the World

To view the prevalence of undernourishment in developed and underdeveloped countries click here [source: SOFI 1999].

More than a quarter of the world's chronically hungry people live in countries where the prevalence of undernourishment is very high (35 percent or more). The problem is especially severe in Central, East and Southern Africa. Almost half (44 percent) of the 340 million people living in the 26 countries of these sub-regions are undernourished. Only six countries elsewhere in the world have such high prevalence rates - Afghanistan, Bangladesh, Haiti, the Democratic People's Republic of Korea, Mongolia and Yemen. Around 570 million undernourished people - almost three-quarters of the world total - live in countries where the prevalence of hunger is neither very low (below 5 percent) nor very high (above 35 percent). While Asian countries are about equally divided between the "moderately low" (5-19 percent) and "moderately high" (20-34 percent) categories, most countries in Latin America and the Caribbean fall in the former. Six million undernourished people live in countries where the prevalence is very or extremely low, mainly in the Near East.