Function
One of the best-known eating disorders is anorexia nervosa. This illness is a psychological disorder that causes a severe fear of being overweight. The sufferer will limit their food intake more and more until they are eating little or nothing in a quest to become thinner and to avoid weight gain. The disorder is often considered a young woman's disease, but 10 percent of its sufferers are male. In the most severe cases, the sufferer will starve to death or die from heart failure due to poor nutrition.
Significance
Bulimia nervosa is an illness that can result into similar fears of gaining weight and being fat. Instead of restricting calories, the bulimic seeks to purge the calories from their body. This can be done by throwing up in order to remove the food from the system. It can also be done by the use of diuretics and laxatives to try to take the calories from the body before they have been absorbed. Some bulimics exercise obsessively to try to rid themselves of the calories. Many bulimics combine two or more of these techniques.
Types
Orthorexia nervosa is a different type of eating disorder that is often not rooted in a fear of gaining weight. It can come from a fear of being unhealthy or becoming sick. Sometimes, it arises in someone who is already sick and trying to become well. Orthorexia can cause nutritional deficiencies when sufferers try to eat diets that are limited in variety. Choosing a few healthy items and eating little else can result in nutritional deficiencies and too few calories being eaten.
Features
Pica is a different type of disorder that has been linked to iron deficiency. The disorder leads sufferers to eat items that are non-nutritional. This can be anything from rocks and plaster to chalk or paper. Some sufferers of pica crave raw potatoes and ice. Others crave laundry starch. In rare cases, eating dangerous items such as glass or nails has been discovered. Anemia has been linked to the disorder but few formal studies have been conducted.
Misconceptions
What is eaten isn't the only indicator of an eating disorder. What time a person eats most of their food can also be an issue. Night eating disorder consists of eating most of a person's calories at night. This can result in higher weight, depression and feelings of guilt for the sufferer. It has been linked to depression and other mood disorders.