LONDON (AlertNet) - The many technical terms used by aid agencies and hunger experts to describe the effects of severe food crises can be bewildering. The following definitions seek to add clarity.

Acute malnutrition This is the result of sudden weight loss due to starvation and disease. It often leads to rapid death unless it is caught in time and correctly treated. Even so, it may have long-term effects on physical and mental growth.

According to UNICEF, 14 percent of children under five years old in Niger suffer from acute malnutrition, 25 percent in Afghanistan, 17 percent in Somalia, and 15 percent in Cambodia and Laos.

Famine There is no single definition of famine which everyone agrees on. See TALKING POINT: Why is famine so hard to define? to find out more.

Food insecurity A situation that exists when people do not have secure access to enough food to lead an active and healthy life. It may be caused by the unavailability of food, people’s inability to buy food or poor food distribution. Food insecurity can be constant, seasonal or transitory.

Food security A situation that exists when everyone in a population always has access to enough nutritious food to lead an active and healthy life.

Malnutrition A condition caused by deficiencies, excesses or imbalances in energy, protein and/or other nutrients.

Stunting Low height for age, caused by undernutrition.

Undernourishment Food intake that is insufficient to meet energy requirements continuously.

Undernutrition The result of undernourishment and/or a person’s inability to absorb nutrients properly.

Wasting Where people are much thinner for their height than healthy people - usually caused by starvation or disease.

Sources: International Scientific Symposium on Measurement and Assessment of Food Deprivation and Undernutrition, WFP, UNICEF

For more food definitions, go to Food Insecurity and Vulnerablility Information and Mapping Systems (FIVIMS)