In recent years, researchers and clinicians have become increasingly aware of the relationship between Autism Spectrum Disorder (ASD) and Anorexia Nervosa (AN). What was once considered an unusual overlap is now recognised as a significant area of clinical importance.
Research consistently shows that autistic traits and autism diagnoses occur at much higher rates amongst people with anorexia nervosa than in the general population. This has important implications for assessment, treatment, and recovery. Understanding this relationship can help ensure that autistic individuals receive appropriate support and avoid treatments that may not fully address their underlying needs.
What is Anorexia Nervosa?
Anorexia nervosa is a serious eating disorder characterised by:
- Persistent restriction of food intake leading to significantly low body weight.
- An intense fear of gaining weight or becoming fat.
- Disturbance in the way body weight or shape is experienced.
- Behaviours that interfere with weight gain.
It has one of the highest mortality rates of any psychiatric disorder and often requires specialist treatment.
What Does the Research Say About Autism and Anorexia?
The link between autism and anorexia was first highlighted by Swedish psychiatrist Christopher Gillberg in the 1980s. Since then, numerous studies have found elevated rates of autistic traits and autism diagnoses amongst individuals with anorexia nervosa.
A 2017 literature review concluded that, despite methodological differences between studies, research consistently demonstrates an over-representation of autistic characteristics in people with anorexia nervosa.
More recently, a 2024 systematic review and meta-analysis examined 22 studies involving over 1,100 individuals with anorexia nervosa. The researchers found that people with anorexia demonstrated significantly higher levels of autistic traits than healthy controls.
How Many People With Anorexia Are Autistic?
Research findings vary because studies use different diagnostic tools and examine different populations. However, several key findings provide useful estimates:
Diagnosed Autism
A review of the literature found that the proportion of individuals with anorexia who either met criteria for autism or displayed substantial autistic traits ranged from 4% to 52%, depending on the study and assessment methods used.
Positive Autism Screening Results
A 2024 meta-analysis reported that approximately 29% of children and adults with anorexia nervosa scored above the cut-off for autism on the Autism Diagnostic Observation Schedule (ADOS), suggesting clinically significant levels of autistic symptomatology.
Autistic Traits
Researchers consistently find elevated autistic traits amongst people experiencing anorexia, even when they do not meet full diagnostic criteria for autism.
Taken together, these findings suggest that autism and autistic traits are substantially morecommon in people with anorexia nervosa than in the general population.
Why Are Autism and Anorexia Linked?
Researchers do not believe there is a single explanation. Instead, several autistic characteristics may increase vulnerability to restrictive eating behaviours.
Cognitive Rigidity and Preference for Sameness
Many autistic people prefer predictability, routine, and consistency. This cognitive style can sometimes contribute to rigid eating patterns.
Some individuals may:
- Eat the same foods repeatedly.
- Follow strict food-related rules.
- Become distressed when routines change.
- Find flexibility around meals challenging.
These characteristics may overlap with behavioural patterns commonly observed in anorexia nervosa.
Sensory Differences
Sensory sensitivities are a core feature of autism and can have a significant impact on eating.
Autistic individuals may experience strong reactions to:
- Food textures.
- Smells.
- Taste.
- Temperature.
- Appearance of foods.
For some people, food restriction develops partly due to sensory difficulties rather than concerns about body image alone.
Social and Emotional Differences
Research suggests that some autistic people experience difficulties with:
- Identifying emotions.
- Communicating distress.
- Managing anxiety.
- Coping with uncertainty.
Restrictive eating behaviours can sometimes develop as a way of creating predictability or managing overwhelming emotions.
Perfectionism and Detail-Focused Thinking
Autistic individuals often show strengths in attention to detail and systematic thinking. In some circumstances, these traits can contribute to highly structured or rule-based approaches to eating, exercise, or weight management.
Why Autism Often Goes Unrecognised in Eating Disorder Services
Autism has historically been under-recognised in eating disorder settings, particularly amongst women and girls.
Many autistic females develop effective masking strategies, consciously learning social behaviours that make autism less obvious to others. Consequently, clinicians may focus on the eating disorder while missing underlying neurodevelopmental differences.
Research suggests that autistic people with anorexia often present with:
- More complex clinical profiles.
- Higher levels of anxiety and depression.
- Greater social difficulties.
- Poorer psychological outcomes compared with non-autistic individuals with anorexia.
Implications for Treatment
The growing evidence for an autism-anorexia overlap has important implications for treatment.
Traditional eating disorder interventions are often developed for neurotypical populations. However, autistic individuals may benefit from adaptations such as:
- Greater predictability and structure.
- Sensory-informed meal planning.
- Adjustments to communication styles.
- Longer treatment pathways where required.
- Recognition that difficulties may relate to autism as well as body image concerns.
Researchers have increasingly highlighted the need for neurodiversity-informed eating disorder services that recognise the unique needs of autistic people.
When Should Someone With Anorexia Consider an Autism Assessment?
An autism assessment may be worth considering if a person with anorexia has a lifelong history of:
- Social communication differences.
- Sensory sensitivities.
- Strong preference for routines.
- Highly focused interests.
- Feeling different from peers.
- Difficulty adapting to change.
- Repetitive behaviours or stimming.
- Challenges that existed before the eating disorder developed.
Particular consideration should be given when eating difficulties appear to be driven by sensory needs, predictability, or rigidity rather than concerns about weight, shape, or appearance alone.
Conclusion
Evidence increasingly demonstrates a significant relationship between autism and anorexia nervosa. While studies vary, research consistently shows that autistic traits and autism diagnoses occur at much higher rates amongst people with anorexia than would be expected by chance.
Recent meta-analytic evidence suggests that around 29% of individuals with anorexia score above the threshold for clinically significant autistic symptomatology, while broader reviews report autism or autistic traits in anywhere from 4% to 52% of anorexia populations depending on the assessment method used.
For clinicians, patients, and families, recognising this overlap is essential. Identifyingunderlying autism can help explain longstanding difficulties, improve access to appropriate support, and ensure that treatment is tailored to the individual’s neurodevelopmental profile rather than focusing solely on the eating disorder itself.
References
Gillberg, C., Råstam, M. and Wentz, E. (2021) ‘Adolescents with autism spectrum disorder and anorexia nervosa comorbidity: common features and treatment possibilities with cognitive remediation therapy and oxytocin’, Frontiers in Psychiatry, 12, Article 686030.
Inal-Kaleli, I., Dogan, N., Kose, S. and Bora, E. (2024) ‘Investigating the presence of autistic traits and prevalence of autism spectrum disorder symptoms in anorexia nervosa: a systematic review and meta-analysis’, International Journal of Eating Disorders.https://onlinelibrary.wiley.com/doi/pdf/10.1002/eat.24307
Leppanen, J., Sedgewick, F., Halls, D. and Tchanturia, K. (2022) ‘Autism and anorexia nervosa: longitudinal prediction of eating disorder outcomes’, Frontiers in Psychiatry, 13, Article 985867. https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2022.985867/full
Westwood, H. and Tchanturia, K. (2017) ‘Autism spectrum disorder in anorexia nervosa: an updated literature review’, Current Psychiatry Reports, 19(7), 41.
