Penny McCubbins, age 15, of Meridian, Miss., for her question:

JUST EXACTLY WHAT IS MALNUTRITION?

Malnutrition is an unhealthy condition caused by poor intake, absorption or use of nutrients by the body.

Primary malnutrition results when the body does not get enough food or the right kinds of food. Secondary malnutrition occurs when, because of disease, the body connot use nutrients even though they are present in the food.

There are a number of types of malnutrition, depending on the nutrient or nutrients missing. Protein calorie malnutrition occurs when the diet is particularly low in calories. It is called kwashiorkor if the diet is especially low in proteins.

Malnutrition caused by a low intake of vitamins may lead to vitamin deficiencies. Various diseases result from deficiencies of different vitamins.

Social and economic conditions as well as natural conditions such as flooding and drought may produce malnutrition. Poverty, war, disease and ignorance also cause malnutrition.