Although starving children may be the first thing that comes to mind when many people think of malnutrition, malnutrition can refer to either being undernourished or overnourished. Being underweight, overweight or not getting enough essential nutrients, such as vitamins and minerals, can affect your disease risk. In some cases, malnutrition increases your risk for certain diseases and health problems, while in other cases, it is the actual cause of the condition.
Vitamin A Deficiency
Not getting enough vitamin A can cause a condition known as xerophthalmia, which begins with dry eyes and night blindness but can eventually lead to total blindness if the deficiency isn't corrected. A more serious complication of vitamin A deficiency is lowered immune function, which makes children more susceptible to other illnesses. Malnutrition potentially increases a child's risk of becoming sick and of dying from diarrhea, acute respiratory infections, measles and malaria, according to the World Health Organization. Vitamin A interventions in developing countries have led to decreases in child deaths of between 19 percent and 54 percent, according to an article published in "Food and Nutrition Bulletin" in December 2003.
Niacin and Iodine Deficiencies
Not getting enough niacin can cause pellagra, characterized by diarrhea, rashes on the skin and, if the deficiency isn't corrected, dementia and death. Children who don't get enough iodine may develop a goiter, or enlarged thyroid, and those born to mothers with this deficiency may suffer from cretinism and be stunted both mentally and physically.
Vitamin D Deficiency
Vitamin D deficiency is a growing problem even among children in the United States. Not getting enough of this essential nutrient can cause rickets, typically associated with bowed legs due to soft bones. Rickets can also cause weak bones that break very easily, bone pain, skeletal deformities, muscle cramps, impaired growth and dental deformities.
Iron-deficiency anemia is one of the more common nutritional deficiencies around the world. If children don't get enough iron, they don't make enough hemoglobin for their red blood cells, so they don't get as much oxygen carried to their cells. This can make them tired, pale, dizzy and irritable and may cause a rapid heartbeat and a decrease in appetite. Iron-deficiency anemia also slows brain development, decreases immune function and decreases school performance.
Being obese itself doesn't necessarily cause disease, but it increases the risk for a number of health problems. Obese children are more likely to have high cholesterol, high blood pressure, joint problems, breathing problems, type-2 diabetes, gallstones, acid reflux and fatty liver disease than children of normal weight, according to the Centers for Disease Control and Prevention. As they get older, they are also more likely to develop heart disease, cancer and diabetes.