Psychological Disorders

Feeding and Eating Disorders

Feeding and eating disorders have biological and environmental causes. Anorexia nervosa involves excessive weight loss and an inaccurate perception of being overweight. Bulimia nervosa involves a cycle of binging and purging.

In industrialized nations, many people live in an environment of abundant food. Many people have sedentary jobs, and the processed food they eat is loaded with excess calories. Thus, maintaining a normal body weight has become a major issue in many societies.

In addition, movies, shows, and ads bombard people with images of slim, athletic bodies. The gap between these "ideal" bodies and average bodies leads to distress about body weight and shape. These cultural factors help explain the rise in eating disorders over time.

Anorexia nervosa is an eating disorder in which a person refuses to eat and does not maintain a normal body weight for their height and frame. They have an intense fear of becoming fat and perceive themselves as fat even when they are very underweight. Women with anorexia often stop menstruating. One risk factor for anorexia is dysfunctional family dynamics, where parents set excessively high standards for their children. People with anxious, compulsive, and perfectionist personality traits are also at risk for this disorder. Anorexia affects mostly girls and women (about 10 percent of those with anorexia are male). Men may express body image problems in other ways, such as obsessive focus on building muscle mass.

Bulimia nervosa is characterized by frequently eating large amounts of food followed by purging. For a diagnosis, people must binge at least twice each week over a period of at least three months. Feelings of guilt, shame, or disgust lead to purging (eliminating the food consumed) with the help of vomiting, laxatives, vigorous exercise, or fasting. People with bulimia, like those with anorexia, are obsessed with body shape and weight. The roots of bulimia lie in cultural pressure to be slim, oversensitivity, low self-esteem, and an excessive drive for achievement. Sometimes people with eating disorders also experience depression, anxiety, impulsivity, and mood swings. Those with bulimia are also at risk for developing obesity. Binge eating disorder involves overeating followed by distress but no efforts to purge.

Anorexia and bulimia nervosa have both physical and psychological consequences. Continually starving the body disrupts memory, causes depression and fatigue, and impairs thinking. It can lead to organ damage and heart failure. Binging and purging can damage the teeth and throat, cause facial swelling, and lead to dehydration and electrolyte imbalance. Electrolyte imbalance is an even greater risk for people with anorexia nervosa. Electrolyte imbalance means that the body has an incorrect balance of sodium, potassium, calcium, or other essential elements. This imbalance can lead to death and is one of the reasons eating disorders have the highest mortality rate of any mental illness. People with anorexia die at about six times the rate of people without the disorder.

How Anorexia Affects the Body

While anorexia is a psychological disorder, the eating disorder has negative physical effects throughout the body.
Although anorexia and bulimia nervosa are the best known feeding and eating disorders, there are other eating disorders, such as pica. Pica involves eating nonfood items, such as paper, soap, paint, dirt, chalk, and cloth. To count as a disorder, the consumption of non-food items must be developmentally inappropriate and cause problems such as intoxication, poisoning, or blockage of intestines. Pica can be caused by nutritional deficiencies that produce unusual cravings or by intellectual disabilities.