In addition to identifying the causes and physical effects of various nutritional deficiencies, this discussion describes the effects of each deficiency on the learning process. The recommended daily food intake for children and teenagers is also noted. Eight types of nutritional deficiency are discussed in detail: (1) malnutrition (both marasmus--calorie deficiency and kwashiorkor--protein deficiency); (2) protein excess; (3) hyperkinesis (hyperactivity--possibly related to food additives); (4) sugar excess; (5) lead poisoning; (6) iron deficiency; (7) vitamin deficiency; and (8) hunger. Other problems discussed are the effects of not eating breakfast and the effects of increased stress. Finally, some information is given on changes in federal programs that help alleviate nutritional problems of low income children. Parents and health and education practitioners are encouraged to strive to improve children's nutrition. (CB)