A psychological disorder in which the person has an intense desire due to social or peer pressure to be thin, often complicated by troubled family relations.  The person may be grossly underweight, but still believe themselves to be fat.  They may resist eating, self induce vomiting, and exercise vigorously, even though their body weight may be more than 25% below the standard.  It is a serious disorder which is beyond the person’s ability to control. This self-starvation leads to a deficiency in essential nutrients, which can cause health complications.