What is an atypical eating disorder?

An atypical eating disorder isn’t something that many people are familiar with or have even heard of. Typically, an eating disorder is described as 'atypical' if it has features that closely resemble anorexia or bulimia but doesn't meet the precise diagnostic criteria of either one.

Some eating problems don't fit into the more common diagnostic boxes, but it doesn’t mean that they’re any less serious or dangerous. They still need to be treated. Eating disorder helplines, GPs and therapists are always there to help support someone suffering from an atypical eating disorder. 

A few examples of why an eating disorder may be atypical include:

• The person’s weight may be just above the diagnostic threshold for anorexia
• Binge eating and purging may occur but not often enough to be classed as a ‘problem’
• In women, if body mass index (BMI) is less that 17.5 but menstruation still takes place

Atypical anorexia nervosa fulfils some of the features of anorexia but the patient’s overall clinical picture does not justify being diagnosed as anorexic. For example, the patient could have a fear of becoming fat and may no longer be menstruating due to their low weight, but there might not have been any drastic weight loss that has taken place.

Atypical bulimia follows a similar pattern because there may be recurrent bouts of overeating and purging or overuse of laxatives, but the patient may not undergo a significant weight change or have the typical concern about body shape and weight.

Due to the inexact symptoms of an atypical eating disorder, it can be very difficult to recognise and diagnose. However, some key symptoms may include:

• Going through periods of being severely underweight followed by periods of being severely overweight
• Eating habits have undergone changes that are uncharacteristic of the person
• The person is no longer engaging in social activities they used to enjoy. They may also be avoiding friends and family so that the problem isn’t identified