Specific traits are linked to each of the disorders. People with anorexia tend to be perfectionist, for instance, while people with bulimia are often impulsive. Physical factors such as genetics also may play a role in putting people at risk.

A wide range of situations can precipitate eating disorders in susceptible individuals. Family members or friends may repeatedly tease people about their bodies. Individuals may be participating in gymnastics or other sports that emphasize low weight or a certain body image. Negative emotions or traumas such as rape, abuse or the death of a loved one can also trigger disorders. Even a happy event, such as giving birth, can lead to disorders because of the stressful impact of the event on an individual's new role and body image.

Once people start engaging in abnormal eating behaviors, the problem can perpetuate itself. Binging can set a vicious cycle in motion, as individuals purge to rid themselves of excess calories and psychic pain, and then binge again to escape problems in their day-to-day lives.