The Pros and Cons of the Diagnosis of “Atypical Anorexia”

I’ll take a break from the recent series of posts to write a few thoughts about the diagnostic construct of “atypical anorexia” recently described in the media.

The concept is not new, but the recently coined term is. People’s bodies and minds respond differently to food restriction or starvation. Anorexia until now referred to people who severely restricted their food and whose bodies lost a significant amount of body weight. The medical effects on their bodies combined with the psychological effects of being chronically underweight outlined a constellation of symptoms treated as Anorexia Nervosa.

The illness was also borne out of a societal obsession with thinness and a morbid curiosity of severely underweight girls. Accordingly, both the culture and the medical field has had strong feelings about the illness and in fact glorified a potentially fatal condition as the apotheosis of self-control.

There have always been people who severely restrict their food and whose bodies respond differently. Some people maintain a typical weight and others paradoxically end up at higher weights from restricting.

The reason is that metabolism—the way a body digests and uses energy from food—adapts to food restriction. Some people store the energy and can function at a high level on much less energy than others, while some use the energy and lose weight rapidly.

The ability to conserve energy is an adaptation to survive famine. Often these people don’t experience food and weight obsession as intensely as people who are at very low weights and see limited decline in cognitive function the way people who are very underweight do.

A more accurate assessment of restrictive disorders is to separate the illnesses into categories. “Atypical anorexia” implies that anorexia has a common and uncommon variant, but these are simply the body’s differing response to food restriction. It makes more sense to name these as separate illnesses in order to make clear what distinguishes them and to differentiate the treatment as well.

Anorexia Nervosa is a specific illness that ought to continue to describe the symptoms and disorder already known medically and culturally. Other restrictive disorders need a new nomenclature.

Although it’s valuable to broaden the scope of eating disorder diagnoses, a more thoughtful approach to the classification will avoid confusion and misguided treatment for all eating disorder patients.