Some mental disorders are characterized by severe disturbances in eating behavior specific diagnoses, anorexia and bulimia nervosa. Anorexia nervosa are that the individual refuses to maintain a minimally normal body weight and is intensely afraid of gaining weight the term anorexia is a misnomer because loss of appetite is rare. Diagnostic and statistical manual of mental disorders Fourth Edition DSM- IV- TR.(pg. 583). Stated disorders of feeding and eating that are usually first diagnosed in infancy or early childhood (i.e., Pica, Rumination Disorder, and Feeding Disorder of infancy or Early Childhood) are included in the section "Feeding and Eating Disorders of Infancy or Early Childhood" (pg. 103).
People with eating disorders fear gaining weight or becoming fat also known as Criterion B. Concerns of weight gain often become high even as weight continues to drop. Many people feel very over weight. Other people realize and understand they are thin, but are afraid that certain parts of their body are "too fat". Specifically their buttocks, thighs or abdomen. To keep track of their weight they find a wide variety of activities. Particularly to estimate their size or weight. Such activities are constant weighing obsessive measuring of the body parts, and constantly using the mirror to get a big picture of were areas of fat lye. Persons with anorexia nervosa self-esteem are highly depending on their shape as well as their weight. Weight loss is seen upon as a great achievement and also great self-discipline. Weight gain, on the other hand is seen as an unacceptable failure of self-control. .
Amenorrhea, in post menarche females is an indicator of dysfunction in anorexia nervosa physiologically. A consequence of weight loss is amenorrhea. In a minority of individuals it may actually precede through. In prepbertal females an illness may delay monarch.
There are two specific subtypes.