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People with large brains may be more susceptible to eating disorders.

A new study reveals that teens with anorexia nervosa have bigger brains than those who don't have the eating disorder. 

Researchers compared a group of adolescents with anorexia nervosa to a group without and found that anorexic girls had a larger insula, a part of the brain that activates when tasting food, and a larger orbitofrontal cortex, a brain region that tells people when to stop eating.

Lead researcher Dr. Guido Frank, MD, assistant professor of psychiatry and neuroscience at CU School of Medicine say the latest findings suggest that the bigger brain may be the reason anorexics are able to starve themselves.

Researchers said that previous research also suggests that insula and orbitofrontal cortex brain size could predispose a person to develop eating disorders. Other studies revealed similar results in children with anorexia nervosa and adults who had removed from the disease.

"While eating disorders are often triggered by the environment, there are most likely biological mechanisms that have to come together for an individual to develop an eating disorder such as anorexia nervosa," Frank said in a news release.

The study involved 19 adolescent girls with anorexia nervosa and 22 in a control group.  Using magnetic resonance imaging (MRI) to study brain volumes, researchers found that people with anorexia nervosa showed greater left orbitofrontal, right insular, and bilateral temporal cortex gray matter compared to the control group.  

Researcher found that orbitofrontal gray matter volume related negatively with sweet tastes in people with anorexia nervosa. Further analysis revealed that adults with anorexia nervosa also had greater orbitofrontal cortex and insula volumes compared to healthy adults.

Researcher explain that a larger medial orbitofrontal cortex, which has been associated with signaling when people feel satiated by a certain type of food, could be trait across eating disorders.  A larger volume in this brain area could promote anorexics to stop eating before eating enough.

The findings are published in the Journal of the American Academy of Child and Adolescent Psychiatry.