When most people hear about eating disorders, they typically think of anorexia, bulimia, and maybe even binge eating disorder. Binge eating disorder (BED) is receiving more attention lately than it has in the past--and as a side note, Cynthia Bulik, the Director of the UNC Eating Disorders Program, recently wrote a great book on binge eating called Crave that is worth checking out.
Anyways, what you may not know is that the way in which these eating disorders present themselves can differ from person to person. We are always learning more about eating disorders as research is being done, and recently, there have been an increasing number of discussions about a variation of anorexia called orthorexia. To be clear, orthorexia is not defined as its own type of eating disorder-- it is not included in the Diagnostic and Statistical Manual of Mental Disorders. Orthorexia is different from anorexia in its motivation, in that one who is orthorexic is not necessarily trying to lose weight or be thin; rather, one is trying to eat as healthfully as possible. As with all eating disorders, the underlying causes go much deeper than a desire to be thin or to be healthy.
Orthorexia, as defined by the National Association of Eating Disorders (NEDA), is a "fixation on righteous eating." Dr. Steven Bratman is responsible for coining this term, and he describes it as a "pathological fixation on eating proper food." Basically, the idea is that one becomes so obsessed with consuming healthy food, and refuses to eat anything but food that is of a high purity and quality. This may even apply to how a food is packaged. There is often an obsessive compulsive quality that accompanies this type of eating behavior. Most residential facilities that treat eating disorders treat orthorexia and are educated about this form of anorexia. For more information on orthorexia, follow THIS LINK.
Also, visit THIS LINK to read NEDA's information about orthorexia.