Brain changes with eating disorders similar to those in OCD and autism

In children with anorexia nervosa or other restrictive eating disorders, changes in the brain’s outer layer don’t seem to be due to lack of nutrition alone – and some mirror those seen in other neurological conditions

By Grace Wade

15 July 2025

A false-colour nuclear magnetic resonance image of a child’s brain

CNRI/SCIENCE PHOTO LIBRARY

Children with anorexia nervosa have widespread brain changes that can’t be explained by starvation alone. The finding brings us closer to identifying the neurological processes behind the condition, which could lead to better treatments for it.

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Anorexia nervosa, an eating disorder characterised by severe calorie restriction and distorted body image, is poorly understood. Previous research has shown that the brain’s outer layer, called the cortex, is significantly thinner in people with the condition than those without it. But it isn’t clear the degree to which these changes are the result of malnutrition or an indication of the cause of anorexia.

Clara Moreau at the University of Montreal in Canada compared brain scans from children with anorexia to those with avoidant/restrictive food intake disorder (ARFID). Both conditions involve severe food restriction and weight loss, but ARFID isn’t motivated by body image concerns or a fear of gaining weight. Instead, people with ARFID avoid food due to sensory issues, a lack of interest in food or fear of negative consequences like choking, vomiting or gastrointestinal pain. Because both disorders can lead to low body weight and malnutrition, comparing them could reveal brain changes unique to each condition and those caused by starvation, says Moreau.

They collected brain scans from 124 children with anorexia, 50 with ARFID and 116 without an eating disorder. All of the children were under 13 years old and living in France. The researchers compared the magnitude of brain differences between children with eating disorders and those without them.

On average, children with anorexia had significantly thinner cortices than those without an eating disorder. After accounting for body mass index (BMI), anorexia was associated with cortical thinning in 32 brain regions, with the greatest effect seen in the superior parietal lobule, an area involved in processing sensory information. “That can make sense because we know that patients with anorexia have disturbed perception of their body weight, of their size,” says team member Anael Ayrolles at the University of Paris.