Good nutrition is an important part of a healthy lifestyle, and most people would benefit from focusing on eating more healthfully. However, for some people, healthy eating can turn into an unhealthy obsession. Individuals for whom nutritious eating becomes an all-encompassing obsession may be suffering from an eating disorder known as orthorexia nervosa.

Orthorexia nervosa is a term coined by Dr. Steven Bratman, a Colorado specialist in eating disorders. The phrase takes its name from the Greek root words orthos, meaning "right," and orexis, or "appetite." While orthorexia nervosa has gained a lot of attention in the psychiatric community, it is not currently recognized in the Diagnostic and Statistical Manual's list of official eating disorders.

Individuals suffering from orthorexia nervosa may become so obsessed with healthy eating that it intrudes into other areas of their lives. For example, patients frequently create very specific systems for what they are allowed to eat based on the nutritional value of their foods. In many cases, patients restrict their diets to the point that they become underweight. However, unlike patients suffering from anorexia nervosa, an eating disorder driven by a desire to be thin, individuals with orthorexia nervosa seek to attain optimum nutrition and purity through their diets.

Orthorexia nervosa is characterized by a compulsion to eat only foods that are "pure" or "correct." In many cases, patients with orthorexia nervosa spend large amounts of time thinking about healthy food, frequently planning menus a day in advance. As the disorder progresses, the list of foods an individual is allowed to eat may become increasingly restrictive. Because of this, orthorexia nervosa can make it difficult for sufferers to eat outside the home. Patients may begin to feel isolated from others, as their restrictive diet prevents them from participating in many social activities.

Patients with orthorexia nervosa may also suffer from depression or obsessive-compulsive disorder. Generally, sufferers are perfectionistic, placing their value as individuals on their ability to adhere to a "perfect" diet. In this sense, orthorexia nervosa shares many characteristics with anorexia nervosa.

Although orthorexia nervosa is not yet officially recognized by the psychiatric community, patients usually benefit most from psychological treatment. Usually, eating disorder specialists are best equipped to treat patients with orthorexia nervosa. As with other eating disorders, antidepressants or anti-anxiety medications may also be effective in treating orthorexia nervosa.