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Autism & eating disorders

Published: February 2, 2023
Last updated on September 11, 2024

Prevalence of eating disorders & autism

Eating disorders are associated with a higher mortality rate than other mental illnesses. There is no discrimination regarding eating disorders since they affect people of all ethnicities, sexualities, gender identities, ages, and backgrounds. One group, however, is disproportionately affected by these disorders: those with autism spectrum disorders. We are so disproportionally affected that clinicians are advised to screen fro autism when someone presents with an eating disorder.

Eating disorders are prevalent among autistics most likely due to our problems with interoception and anxiety; as a response, some autistic people engage in eating disorders as a way to cope.

70% of autistics have atypical eating behaviours,[1]Atypical eating behaviors in children and adolescents with autism, ADHD, other disorders, and typical development (Dickerson & Zickgraf, 2019) while up to 30% of us have an eating disorder.[2]Trajectories of autistic social traits in childhood and adolescence and disordered eating behaviours at age 14 years: A UK general population cohort study (Solmi et al., 2021) This is over 3 times the prevalence rate of the general population, which is 9%.[3]Eating Disorder Statistics | ANAD

We also are disproportionately represented in treatment centers, with up to 35% of people who are treated for an eating disorder being autistic.[4]Supporting people with autism experiencing eating disorders | Maudsley Center

Until recently, it was unclear whether autistic traits resulted from eating disorders or preceded them. In a recent longitudinal study published in the Journal of Child Psychology and Psychiatry, researchers found that autistic traits preceded eating disorders and may be a predictor of eating disorders in the future.[5]Children with autism face higher risk of eating disorders, study finds (2020) | ScienceDaily[6]Trajectories of autistic social traits in childhood and adolescence and disordered eating behaviours at age 14 years: A UK general population cohort study (Solmi et al., 2021)

Researchers have postulated that alexithymia (difficulty identifying and describing emotional states) may explain the relationship between autistic and eating disorder.[7]Alexithymia may explain the relationship between autistic traits and eating disorder psychopathology (Vuillier et al., 2020) Follow the link below to learn more about alexithymia in autism.

Alexithymia & autism guide

My experience

I eat a wide range of food, likely due to significant travel during my early childhood. I grew up in London, Paris, Venice, Rome, South Africa, the USA (including Michigan, Pennsylvania, Florida, and California), Canada, Japan, and Hong Kong. So I was constantly exposed to different foods. My childhood memories include foods I refused to eat, such as bananas on peanut butter sandwiches. Coconut on my chicken once caused a meltdown when I was ten.

Certain aspects of my eating are relatively restricted. I have the same breakfast daily—heated Holy Crap chia cereal with apples and cinnamon in cooler weather and chocolate banana smoothies in warmer weather. I tend to get GERD or indigestion when I deviate too far from these choices. Moreover, I shouldn’t eat anytime close to sleeping (at night or before a nap) because it causes me to feel sick.

That said, I have had an eating disorder, specifically bulimia. For me, it was something that, in a sense, just happened. I always had a sensitive stomach. As a child, I often threw up without provocation when we had guests. Also, anytime I was stressed, I would feel nauseated, and after I threw up, I felt better. Why? When we vomit, our body releases vomiting-induced endorphins or endogenous opioid peptides that make us feel better. In addition, vomiting is also associated with falls in depression and anxiety.[8]Bulimic vomiting alters pain tolerance and mood (Abraham & Joseph, 1986) So it is easy to see how the brain can unconsciously link throwing up to feeling better. Especially for those of us who struggle with anxiety.


Anorexia nervosa

Anorexia nervosa is often characterized by a significantly low body weight, especially if it’s much lower than expected based on the person’s age and height.

Research shows that people with anorexia are more likely to be autistic than those without anorexia.[9]Do girls with anorexia nervosa have elevated autistic traits? (Baron-Cohen et al., 2013)

Common symptoms

Anorexia may also cause the following symptoms:

  • Missing meals or eating little
  • Limiting consumption of high-calorie foods
  • Lying about what they ate
  • Excessive exercise

Causes

For autistic women with anorexia, weight and body shape may not be as consequential as other autism-related factors.[10]Autism symptoms in anorexia nervosa: a comparative study with females with autism spectrum disorder (Kerr-Gaffney et al., 2021) Research shows that anorexia in autism is caused by:

  • Having a high level of anxiety
  • A rigid, rule-driven approach to eating and exercising
  • Food-related sensory problems
  • Difficulties sensing hunger

Avoidant/restrictive food intake disorder

Similar to anorexia, avoidant/restrictive food intake disorder (ARFID) is a type of eating disorder. ARFID differs from anorexia in that people with ARFID don’t worry about their body image. There are intense restrictions on the type and amount of food you can eat in both conditions.

It is common for children to go through phases of picky eating. ARFID (formerly known as selective eating disorder) is a different disorder. When someone has ARFID, their bodies do not get enough calories to function correctly. Children can suffer from delayed weight gain and growth as a result. Adults who suffer from ARFID may lose weight dangerously, but they may also lose the ability to maintain basic body functions.

Causes

There is no known cause of ARFID, though genetics is believed to be a factor.[11]Estimating the Prevalence and Genetic Risk Mechanisms of ARFID in a Large Autism Cohort (Koomar et al., 2021) It is believed that 1 in 10 autistics may have extreme sensitivity to taste or texture, and 17% of their parents may struggle with ARFID as well.[12]Estimating the Prevalence and Genetic Risk Mechanisms of ARFID in a Large Autism Cohort (Koomar et al., 2021) They might be anxious or fearful about food because they had a bad experience with food, such as choking or vomiting.

ARFID is most likely to affect:

  • Those who never outgrow picky eating
  • Autistic individuals
  • People with ADHD

Anxiety disorders are common among kids with ARFID. In addition, they are more likely to suffer from other psychiatric disorders.


Binge eating disorder

Research shows that not only anorexia nervosa but also bulimia and binge eating disorder (BED) patients show greater autistic traits compared to non-autistics.[13]Autistic Traits in Patients with Anorexia Nervosa, Bulimia Nervosa or Binge Eating Disorder: A Pilot Study (Gesi et al., 2020)

Binge eating is characterized by compulsive overeating. As with bulimia, this diagnosis requires at least one binge per week. Those suffering from this disease cannot control their behaviours and will eat long after their appetite has been satisfied; or even when they are not hungry. In contrast to other eating and food issues, there are no subsequent episodes of purging.[14]Binge-Eating Disorder in Adults (Brownley et al., 2016)[15]Binge-Eating Disorder: Clinical foundations and treatment (Halmi, 2010) Afterward, they often feel depressed and ashamed. In addition, there are no telltale weight parameters; victims could be within average weight for their age and height or slightly overweight or obese. It can lead to obesity, diabetes, heart complications, and other health problems.


Bulimia nervosa

In bulimia nervosa, people cycle between diets, binges, and purges. Those who binge may feel out of control and continue eating despite feeling uneasy or nauseated. 

According to the DSM, for a person to be diagnosed with bulimia, they must binge at least once a week. When patients binge, they tend to compensate by fasting, exercising, or purging. Underweight people who exhibit these behaviours are considered to have binge-eating/purging anorexia.

Common symptoms

As well as similar symptoms to those associated with anorexia, people with bulimia may also experience the following symptoms:

  • Sore throat
  • Swollen salivary glands in the cheeks
  • Heartburn and acid reflux
  • Dental decay
  • Diarrhea
  • Esophageal tears
  • Gastric rupture

Diagnosis

Accurately assessing the prevalence of autism in anorexia is challenging, despite its benefits. In females with autism who have not been diagnosed in childhood, secondary mental health problems such as anorexia may obscure their autism spectrum disorder (ASD) diagnosis when manifested by extreme rigidity or obsessive interest in calories or exercise.[16]Identifying the lost generation of adults with autism spectrum conditions (Lai & Baron-Cohen, 2015)

Despite the high co-occurrence of autism and eating disorders, we mustn’t diagnose autism in a person who is in a state of starvation, as this can mimic autistic traits. The tools used to treat autistics with eating disorders may be helpful for non-autistics with anorexia due to them demonstrating similar traits to autism.

On a screening questionnaire for autism, one out of four of the 150 patients receiving outpatient anorexia treatment in a London clinic scored above the cutoff for autism.[17]An examination of autism spectrum traits in adolescents with anorexia nervosa and their parents (Rhind, 2014) Even though they did not have a clinical diagnosis, the girls exhibited high levels of autism traits.

Do not diagnose a person with anorexia while in starvation mode, as anorexics tend to score higher on social-communication difficulties tests than controls do.[18]The sociocommunicative deficit subgroup in anorexia nervosa: autism spectrum disorders and neurocognition in a community-based, longitudinal study (Anckarsäter, 2011)


Alexithymia

It is crucial to investigate how much alexithymia contributes to these detrimental outcomes—rather than autism itself—since autistic individuals have high suicide rates and a greater risk of eating disorders. There is a possibility that these risks can be reduced with targeted interventions for alexithymia.[19]Alexithymia may explain the relationship between autistic traits and eating disorder psychopathology, Vuillier et al, 2020.

Follow the link below to learn more about alexithymia in autism.

Alexithymia & autism guide

Treatment

Childhood diagnoses are overrepresented in those with an adult autism diagnosis. Attention deficit hyperactivity disorder (ADHD), affective disorders, anxiety, stress-related disorders, and eating disorders were the most prevalent childhood conditions. The majority of these childhood conditions were not diagnosed until after age 12, with 69% of males and 61% of females with adult autism diagnoses did not receive any investigation for these co-occurrences before they turned 18.[20]Childhood diagnoses in individuals identified as autistics in adulthood (Rødgaard et al. 2021)

There are currently no treatment guidelines for helping autistic people with eating disorders. Consequently, clinicians I have spoken with report lacking confidence and knowledge in treating eating disorders with autism. I want to provide suggestions and adaptations to help autistics with eating disorders gain a better understanding of—and higher confidence in—treatments.

When considering a patient with anorexia nervosa, it is crucial to determine whether it is the result of starvation or underlying autism. There is a high overlap in traits and brain effects associated with starvation and autism. Even though people with eating disorders (without co-occurring autism) tend to have more sensory sensitivities, these profiles are usually not as extreme as those seen in people with autism.

Autism–anorexia comorbidity is being treated more effectively in recent years due to earlier and better recognition of autism, especially in girls, and to the development of interdisciplinary programs for youth with autism. Current literature suggests Cognitive Restructuring Therapy and oxytocin application could also benefit young patients with anorexia and autism—among other interventions and therapies.[21]Adolescents With Autism Spectrum Disorder and Anorexia Nervosa Comorbidity: Common Features and Treatment Possibilities With Cognitive Remediation Therapy and Oxytocin (Tololeski, Grabner, & Kumperscak, 2021)


Prognosis

The lack of support and research regarding autism with co-occurring eating disorders has resulted in poorer treatment outcomes.

However, recent research showed that when eating disorders are caught early, a family-based approach’s success rate is as successful as for non-autistics.[22]Adolescents With Autism Spectrum Disorder and Anorexia Nervosa Comorbidity: Common Features and Treatment Possibilities With Cognitive Remediation Therapy and Oxytocin (Tololeski, Grabner, & Kumperscak, 2021)

Researchers followed a large group of autistics with eating disorders, all of whom did family-based therapy, and all recovered.[23]Preventing eating disorders and disordered eating in genetically vulnerable, high-risk families (Levine & Sadeh-Sharvit, 2022)


Adaptations to treatment to accommodate the characteristics of autism

  • Autistics with eating disorders often have co-occurring alexithymia (difficulty with interoception and identifying emotions); in fact, alexithymia may be part of why the eating disorder started in the first place. Therefore, spending more time on emotion education and anxiety management is essential.
  • Increasing body awareness, such as sensory processing, proprioception, and interoception, is vital.
  • A mindful movement practice such as Yoga can be beneficial. That said, groups can be challenging for autistics, so groups should be all autistic or, at the very least, have 3 autistics to 1 neurotypical.
  • Training to increase interpersonal and friendship skills is valuable.
  • Ensure that there is staff training in autism. Non-autistics need to remember that it will be easier to understand and communicate with people from a different culture, than to understand and communicate with us. Part of that is autistics and non-autistics have contrastive brain structures. Statements like, ‘Do sounds affect you significantly?’ will translate to a non-autistic, ‘Do sounds affect you?’, while to an autistic it will mean, ‘Do sounds affect you a lot?’.
  • Be aware of autistics’ sensory issues and accommodate these. For example, I find zoom calls fine unless someone is using background and they are moving a lot; it can make me ill. Or when I go to a class, I like to have the overhead lights off if there is enough natural light. So I suggest having your clients check off a list of their sensory issues and how significantly they will affect them.
  • Typically we are better with fewer people, as more people equals more socializing we’ll have to manage. If the entire group is autistic, this may be of less concern—we do not have to camouflage.
  • Socializing is exhausting, so consider the duration of sessions. In addition, we tend to think of a lot of questions regarding information. For example, when I review a seminar that is an hour, I will often spend about 8 hours researching extra information.
  • Have continuity of staff where possible due to difficulty with transition and change
  • Have an autism expert come in to train their staff and also, in case conferences, have a member invited as an autism expert.

Inpatient treatment

  • Can they have comforts from home
  • Need for solitude
  • Morsely Institue London, UK, is world-leading in terms of treatment regarding autism-anorexia.
  • Consider suitability for Group therapy (social dynamics, empathic attunement, and vulnerability)
  • Consider the duration of sessions (exhaustion)
  • Residential treatment considerations (culture, being away from home, sensory sensitivity, need for solitude)

Resources

References

References
1 Atypical eating behaviors in children and adolescents with autism, ADHD, other disorders, and typical development (Dickerson & Zickgraf, 2019)
2 Trajectories of autistic social traits in childhood and adolescence and disordered eating behaviours at age 14 years: A UK general population cohort study (Solmi et al., 2021)
3 Eating Disorder Statistics | ANAD
4 Supporting people with autism experiencing eating disorders | Maudsley Center
5 Children with autism face higher risk of eating disorders, study finds (2020) | ScienceDaily
6 Trajectories of autistic social traits in childhood and adolescence and disordered eating behaviours at age 14 years: A UK general population cohort study (Solmi et al., 2021)
7 Alexithymia may explain the relationship between autistic traits and eating disorder psychopathology (Vuillier et al., 2020)
8 Bulimic vomiting alters pain tolerance and mood (Abraham & Joseph, 1986)
9 Do girls with anorexia nervosa have elevated autistic traits? (Baron-Cohen et al., 2013)
10 Autism symptoms in anorexia nervosa: a comparative study with females with autism spectrum disorder (Kerr-Gaffney et al., 2021)
11, 12 Estimating the Prevalence and Genetic Risk Mechanisms of ARFID in a Large Autism Cohort (Koomar et al., 2021)
13 Autistic Traits in Patients with Anorexia Nervosa, Bulimia Nervosa or Binge Eating Disorder: A Pilot Study (Gesi et al., 2020)
14 Binge-Eating Disorder in Adults (Brownley et al., 2016)
15 Binge-Eating Disorder: Clinical foundations and treatment (Halmi, 2010)
16 Identifying the lost generation of adults with autism spectrum conditions (Lai & Baron-Cohen, 2015)
17 An examination of autism spectrum traits in adolescents with anorexia nervosa and their parents (Rhind, 2014)
18 The sociocommunicative deficit subgroup in anorexia nervosa: autism spectrum disorders and neurocognition in a community-based, longitudinal study (Anckarsäter, 2011)
19 Alexithymia may explain the relationship between autistic traits and eating disorder psychopathology, Vuillier et al, 2020
20 Childhood diagnoses in individuals identified as autistics in adulthood (Rødgaard et al. 2021)
21, 22 Adolescents With Autism Spectrum Disorder and Anorexia Nervosa Comorbidity: Common Features and Treatment Possibilities With Cognitive Remediation Therapy and Oxytocin (Tololeski, Grabner, & Kumperscak, 2021)
23 Preventing eating disorders and disordered eating in genetically vulnerable, high-risk families (Levine & Sadeh-Sharvit, 2022)
This article
was written by:
dr-natalie-engelbrecht

Dr. Natalie Engelbrecht ND RP is a dually licensed naturopathic doctor and registered psychotherapist, and a Canadian leader in trauma, PTSD, and integrative medicine strictly informed by scientific research.

She was diagnosed at 46, and her autism plays a significant role in who she is as a doctor, and how she interacts with and cares for her patients and clients.

Want to know more about her? Read her About me page.

Disclaimer

Although our content is generally well-researched
and substantiated, or based on personal experience,
note that it does not constitute medical advice.

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