Who Gets Anorexia Nervosa and Bulimia Nervosa

Eating disorders seem to be most prevalent in industrialized societies, especially those in which thinness is considered the attractive ideal. About 90 to 95 percent of the cases of anorexia and bulimia nervosa occur in females. Anorexia usually develops in adolescence, between the ages of 14 and 18, while bulimia is more likely to develop in the late teens or early 20s. It is estimated that anorexia occurs in about 0.5 percent of adolescent girls, and bulimia in about 1 to 2 percent, although various symptoms and milder versions of these disorders occur in about 5 to 10 percent of young women. The large majority of women with eating disorders are white, although in recent years the disorder has been increasing in minority women.

Possible Causes

Several factors may play a role in the onset of anorexia and bulimia, including a familial predisposition to these disorders, as well as individual personality characteristics. However, the stage for eating disorders is set by our society’s glorification of thinness and strong prejudice against those who are overweight. The thin ideal is portrayed in the media (for example, using fashion models and movie stars) and is often linked with social desirability and achievement. As a result, girls and young women are now dieting in record numbers in quest of a leaner shape.

It should be noted that both anorexia and bulimia nervosa were well-documented before the thinness ideal reached its current state, suggesting that this factor alone is not sufficient for the onset of an eating disorder. It may, however, be linked to the increase of cases of both anorexia and bulimia in recent years.

What separates individuals who diet and develop an eating disorder from those who do not experience complications? Genetic studies have found that anorexia nervosa is five times as likely to co-occur in monozygotic (identical) twins than in dizygotic (fraternal) twins or non-twin siblings, suggesting a biological component in the onset of the disorder. In fact, data suggests an increased risk for both anorexia and bulimia nervosa in first-degree biological relatives of an individual with the disorder.

Certain personality characteristics also seem to be associated with these two disorders. Such predisposing factors include the fear of losing control, inflexible thinking, a tendency toward perfectionism, self-esteem which is unduly determined by the individual’s view of her or his body shape and weight, dissatisfaction with body shape, and an overwhelming desire to be thin. Anorexia nervosa also has been linked to obsessive-compulsive tendencies, such as a preoccupation with thoughts of food, while mood disturbances, such as depressed mood or social anxiety, have been associated with bulimia nervosa.