The Columbia Encyclopedia, Sixth Edition. Columbia Encyclopedia World Factbook Columbia Gazetteer American Heritage Coll. Anorexia nervosa is characterized by self-starvation to avoid obesity. People with this disorder believe they are overweight, even when their bodies become grotesquely distorted by malnourishment. Bulimia is characterized by massive food binges followed by self-induced vomiting or use of diuretics and laxatives to avoid weight gain.
Some anorexic patients combine bulimic purges with their starvation routine.
Others contend that these disorders are rooted in societal ideals that value slenderness. Rumination disorder generally occurs during infancy, and involves repeated regurgitation accompanied by low body weight. Infants suffering from rumination disorder may re-ingest the regurgitated food. Pica, also found primarily among infants, is characterized by eating various non-nutritive substances like plaster, paint, or leaves. Obesity is not generally considered an eating disorder, since its causes tend to be physiological.