They were also found to have an above-average interest in systems and order, and below-average scores in empathy - a profile similar, but less pronounced, to that seen in people with autism, suggesting the two disorders may have common underlying features, Baron-Cohen said.
"Traditionally, anorexia has been viewed purely as an eating disorder. This is quite reasonable, since the girls' dangerously low weight and their risk of malnutrition or even death has to be the highest priority," he said.
"But this new research is suggesting that underlying the surface behavior, the mind of a person with anorexia may share a lot with the mind of a person with autism. In both conditions, there is a strong interest in systems. In girls with anorexia, they have latched onto a system that concerns body weight, shape, and food intake."
People with autism have varying levels of impairment across three main areas - social interaction and empathy or understanding, repetitive behavior and interests, and language and communication.
Cohen noted that autism and anorexia share certain features, such as rigid attitudes and behaviors, a tendency to be very self-focused, and a fascination with detail. Both disorders also share similar differences in the structure and function of brain regions involved in social perception.
The findings, researchers say, could help in the development of new treatments for anorexia.
Image: Anorexia sign, via Shutterstock