A diagnosis often viewed as less serious than anorexia and bulimia – and the most common eating disorder worldwide – can cause just as much harm, a new study has found. 

Other Specified Feeding or Eating Disorder (OSFED) is diagnosed when a person’s symptoms don’t fit neatly into the classical categories but are still clinically significant. 

Researchers from McGill University and Douglas Research Centre compared clinical data from adults with OSFED to those with anorexia and bulimia. Across measures of depression, anxiety, well-being, and concerns about shape, weight and eating, they found people with OSFED were just as ill, and in some cases had more severe symptoms. 

“It’s easy to think of OSFED as a ‘catch-all’ or ‘mild’ category,” said lead author Linda Booij, professor in McGill’s Department of Psychiatry and head of research and academic development at the Douglas Eating Disorders Continuum and Research Centre. “Because it doesn’t present like the more well-known conditions, it can be overlooked,” she said. 

The misconception can also lead people to avoid seeking help because they feel their condition isn’t serious enough, she added.

What makes OSFED different 

Anorexia nervosa involves extreme restriction of food intake, driven by an intense fear of weight gain. Bulimia nervosa is marked by cycles of binge eating followed by purging behaviours such as vomiting or misuse of laxatives, which are harmful and ineffective for weight loss, the researchers explain. 

“Someone with OSFED might meet all the criteria for anorexia nervosa, but their weight is not low enough to get a formal diagnosis,” explains Booij. “Another example could be someone who purges frequently but is not underweight and never binges.”  

Up to one in nine young people are affected by OSFED, she said, adding awareness needs to grow within clinics and the broader public. 

“We need to take OSFED seriously,” said Booij. “It’s important to do a thorough assessment and not automatically deprioritize or deny treatment to people because they don’t fit a traditional diagnosis. Some people with OSFED need the same level of care and attention.” 

The study drew on data from 836 patients, mostly women, treated through the Douglas Eating Disorders Continuum, using questionnaires to assess mood, eating-disorder symptoms and overall wellbeing. 

About the study 

“Restrictive and Binge-Purge OSFED Variants: Clinical Features and Comparisons With Classical Eating Disorders” by Linda Booij, Emily Mizzi, Samantha Ginsberg and Howard Steiger was published in the International Journal of Eating Disorders.