Wikipedia defines hunger as a condition in which a person, for a sustained period, is unable to eat sufficient food to meet basic nutritional needs. Some negative effects are:
Health:Hunger and malnutrition make the body weak and vulnerable to diseases and infections as the body does not have the fuel to build muscle and fight off infections.
Education:Without proper foods (with the right balance of vitamins and minerals) the brain is not able to develop properly. Hunger also makes it difficult to concentrate on anything, especially for children.