Disordered Eating and Autism – Obesity

Francesca Solmi, Ph.D., discusses the intricate link between autism and eating disorders. She outlines common eating disorders, noting their overlapping symptoms and similarities to autism traits. The speaker explores potential mechanisms for the connection between eating disorders and autism, including communication difficulties, sensory sensitivities, and emotion regulation. Solmi emphasizes Avoidant/Restrictive Food Intake Disorder (ARFID) and its relevance to autism, underscoring the need for more research and services for this often overlooked condition. The presenter considers future research directions before the Q&A.  

Handouts are online HERE

In this webinar:

1:30 – Common eating disorders
8:00 – Autism and eating disorders
11:00 – Trajectories of autistic traits and eating disorders
20:00 – Potential linking mechanisms
28:00 – Emotion regulation
34:50 – Avoidant/Restrictive Food Intake Disorder (ARFID) and Autism
40:00 – Future research
42:00 – Q&A

Overview of Eating Disorders 

Solmi defines eating disorders as severe psychiatric conditions that typically emerge in early to mid-adolescence. She describes common eating conditions, including Anorexia Nervosa, Bulimia Nervosa, Binge Eating Disorder, and OSFED (Other Specified Feeding or Eating Disorder), highlighting the significant symptom overlaps across conditions (1:35).

• Anorexia Nervosa – frequently the youngest age of onset. Characterized by an intense fear of weight gain, extreme dietary restriction, and often low body weight. Some individuals may also engage in bingeing and purging.
• Bulimia Nervosa – slightly later onset and involves episodes of binging followed by compensatory behaviors like self-induced vomiting or excessive exercise.
• Binge Eating Disorder – the most recently recognized diagnosis. It involves bingeing without compensatory behaviors, often accompanied by feelings of shame or guilt.
• OSFED (Other Specified Feeding and Eating Disorder) is a residual category for individuals whose symptoms don’t fully meet the criteria for other diagnoses. 

The speaker emphasizes the severity of these conditions, noting their association with higher mortality rates (5:00). Despite this, eating disorders are often under-researched compared to other mental health disorders. She also notes their high prevalence in girls and women, suggesting underdiagnosis in men (6:30).  

The Link Between Autism and Eating Disorders 

Solmi discusses the connection between autism and eating disorders. A study by Westwood and colleagues revealed elevated autistic traits in people with anorexia nervosa. Similarly, people with autism and anorexia nervosa mentioned rigidity or rules, intense interests, difficulties recognizing hunger, and social difficulties (8:00). A significant challenge in this research, the presenter explains, is distinguishing between pre-existing autistic traits and those that may be mimicked by severe malnutrition in anorexia nervosa. 

Autism Spectrum Disorder in Anorexia Nervosa: An Updated Literature Review (Westwood et al., 2016)

Research on Autistic Traits and Disordered Eating Trajectories

Solmi presents findings from a study investigating whether autistic traits were present before the onset of disordered eating behaviors (11:00). Researchers found that children who later developed disordered eating behaviors exhibited higher levels of autistic traits at age seven, and these differences persisted throughout adolescence. The speaker asserts that these findings suggest autistic traits may precede the onset of disordered eating (17:00). The study also revealed that more severe eating disorder symptoms correlated with higher autistic trait scores from age seven onwards, indicating a strong association with more severe presentations of eating disorders.

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., 2020)

Potential Mechanisms Linking Autism and Eating Disorders 

The presenter explores several mechanisms as potential links between autism and eating disorders. For example, as friendships become more important in adolescence, struggles with social interaction can exacerbate mental health difficulties, with eating disorders potentially serving as a coping mechanism. Children with social communication difficulties may also be more susceptible to bullying, which can lead to internalized weight-stigmatizing thoughts and behaviors like dieting (20:00). Young people with autism often exhibit more sedentary behaviors compared to their peers, which can increase BMI and vulnerability to weight-based stigmas (23:00). 

Emotion regulation difficulties are also common in both autism and eating disorders. Solmi outlines a recent study showing that individuals who later developed anorexia nervosa symptoms exhibited less improvement in emotion regulation skills from early to mid-childhood compared to their peers, where differences emerged around age five (30:00). Further, in girls, social cognition explained around half of the association between emotion regulation difficulties and disordered eating. The association in boys was less clear, likely due to smaller sample sizes (35:00).

The presenter notes that sensory sensitivities, a core aspect of avoidant/restrictive food intake disorder (ARFID), are frequently reported by people with anorexia nervosa. For example, in a qualitative study on autism and anorexia in women, emerging themes included difficulty with sensory sensitivities, social interactions and relationships, and challenges with emotions (33:00). 

A mixed-methods approach to conceptualizing friendships in anorexia nervosa (Datta et al., 2021)

Autism Spectrum Disorder and Obesity in Children: A Systematic Review and Meta-Analysis (Sammels et al., 2022)

Emotional dysregulation in childhood and disordered eating and self-harm in adolescence: prospective associations and mediating pathways (Warne et al., 2022)

“For Me, the Anorexia is Just a Symptom, and the Cause is the Autism”: Investigating Restrictive Eating Disorders in Autistic Women (Brede et al., 2020)

Avoidant/Restrictive Food Intake Disorder (ARFID) and Autism

Solmi discusses ARFID, a disorder now included in the eating and feeding disorder family, noting its relevance to autism. Its three main aspects include limited interest in food, sensory sensitivities (e.g., avoiding specific foods due to texture), and concerns about adverse consequences from eating (34:50). The speaker emphasizes the limited epidemiological research on ARFID, the lack of services (especially for people who are not severely underweight), and the need for more studies to understand its prevalence, risk factors, and effective treatments (37:00).

Future Research Directions 

According to the presenter, future research should aim to understand the complex links between autism and eating disorders more comprehensively. Key areas of investigation include the connections between sensory sensitivities and ARFID, gender differences in the association of autistic traits and eating disorders, links between other autistic traits and different eating disorder presentations, physiological factors like the gut-brain response, and age of autism diagnosis in those with and without eating disorders. These avenues of research, Solmi asserts, will improve diagnostic tools and help to develop better prevention and care strategies (40:00). The speaker summarizes main points before the Q&A (42:20).