Eating Disorders: Overview and Risk Factors

Anorexia nervosa and bulimia nervosa are common and serious eating disorders. Up to 3 percent of American women suffer from an eating disorder, and up to 20 percent of college-aged women engage in abnormal eating behaviors.

Anorexia nervosa is marked by refusal to maintain normal body weight. Affected individuals have a distorted body image, a body weight at least 15 percent below the expected value, absence of menstrual periods, and abnormal eating behaviors, particularly restricted food intake. About half of patients also have symptoms of bulimia.

Bulimia nervosa is a disease marked by recurrent episodes of binge eating and inappropriate methods to prevent weight gain, such as self-induced vomiting and laxative abuse.

The cause of these disorders is largely unknown, but genetic, psychological, environmental, and social factors are probably involved. Some experts believe that a cultural obsession with thinness and dieting in the United States and other Western countries has set the stage for eating disorders. However, equally likely is that poor dietary habits in Western countries frequently lead to weight gain among children and adolescents. Rather than adopt more healthful dietary habits, many young people turn to dietary restriction or other means to control their intake. Nearly 40 percent of adolescent girls in the United States believe they are overweight, and nearly 60 percent are attempting to lose weight. A substantial number have reported that they have tried vomiting or laxatives to control their weight.

The long-term health issues associated with eating disorders include osteoporosis, damage to certain areas of the brain, electrolyte imbalances, heart disorders, intestinal dysfunction, wearing down of the teeth, and infertility, some of which are irreversible, even with appropriate treatment. Many affected individuals also have other psychiatric disorders, including depression, anxiety, and obsessive-compulsive disorder.

Risk Factors

About 90 percent of cases occur in women, usually beginning in late adolescence and early adulthood. Additional risk factors include:

• History of obesity and/or dieting: A history of obesity is linked to an increased risk for eating disorders. Adolescents who reported dieting during mid-adolescence were significantly more likely to develop eating disorders.
• Participation in activities that emphasize leanness: Examples include ballet, gymnastics, and running.
• Family history: Women who have a first-degree relative with an eating disorder are up to 10 times more likely to develop an eating disorder themselves. Eating disorders are also associated with a family history of depression.
• Psychiatric history: Depression, substance abuse, sexual abuse, weight dissatisfaction, and low self-esteem are linked to a higher risk for eating disorders.
• Early puberty: Early sexual development may lead to increased self-consciousness regarding body image and is associated with subsequent dieting behaviors.