Orthorexia Nervosa

Orthorexia nervosa (also known as orthorexia) is not mentioned in the DSM, but was first used by Steven Bratman to characterize people who develop an obsession with avoiding foods perceived to be unhealthy. Orthorexia nervosa is believed to be a mental disorder. Bratman claims that in rare cases, this focus may turn into a fixation so extreme that it can lead to severe malnutrition or even death. Even in less severe cases, the attempt to follow a diet that cannot provide adequate nourishment is said to lower self-esteem as the orthorexics blame themselves rather than their diets for their constant hunger and the resulting cravings for forbidden foods.

In 2009, Ursula Philpot, chair of the British Dietetic Association and senior lecturer at Leeds Metropolitan University, described people with orthorexia nervosa to The Guardian as being "solely concerned with the quality of the food they put in their bodies, refining and restricting their diets according to their personal understanding of which foods are truly 'pure'." Compared to other eating disorders, such as anorexia nervosa and bulimia nervosa, whereby people "focus on quantity of food".

The term orthorexia derives from the Greek ορθο- (ortho, "right" or "correct"), and όρεξις (orexis, "appetite"), literally meaning a correct diet. It was introduced in 1997 by Doctor of Medicine Steven Bratman, to be used as a parallel with other eating disorders, such as anorexia nervosa.