Sufferers have been known to go to extremes to disguise the disorder. One student said her friend even placed weights on her ankles before doctors' checkups in order to add weight. Using APA's Diagnostic and Statistical Manual of Mental Disorders, Nyles informed the students. He said some anorexics drop to about 85 percent of the normal body weight for their age and height, they have an intense fear of gaining weight or becoming fat, and women lose their menstrual cycle. They tend to be perfectionists and overachievers, but lack self-esteem.
Some theories suggest that a brain chemical imbalance or genetic influences are involved.
Nyles' own theory is that people who grow up in very controlling families feel the need to control at least this area in their lives. Treatment can include psychotherapy, behavior modification, nutritional counseling, and self-help groups. Nyles said that bulimics have recurrent episodes of binge eating, averaging about 5,000 calories per episode. These are followed by induced vomiting or large doses of laxatives. Bulimia may result from social pressures to be thin coupled with poor self-image.