What are the connections between autism and eating disorders?

Eating disorders and autism are two distinct conditions that can coexist in individuals, with approximately 20% of people with an eating disorder also having co-occurring autism.

Although they are separate disorders, there are underlying links and shared biological aspects that connect them. Exploring the relationship between these two conditions requires a deeper understanding of the brain and genetics of individuals with autism.

One significant influence on eating behaviors in individuals with autism is sensory sensitivities.

Many people with autism have heightened or diminished sensory responses to tastes, textures, smells, and visual aspects of food. These sensitivities can lead to food aversions or preferences, resulting in restrictive eating patterns. For instance, some individuals may avoid certain textures that they find unpleasant, limiting their dietary variety and potentially affecting their nutritional intake.

Repetitive behaviors, a core feature of autism, can also extend to eating habits.

Ritualistic or compulsive behaviors related to food may develop, such as eating in a specific order, arranging food items meticulously, or strictly adhering to mealtime routines. These behaviors provide a sense of predictability, control, and comfort in an otherwise unpredictable world. However, when these behaviors become excessively rigid, they can contribute to the development of eating disorders. The need for excessive control and predictability can manifest in different types of eating disorders, including Avoidant Restrictive Feeding Disorder, Anorexia Nervosa, Bulimia Nervosa, Orthorexia, and unspecified eating disorders.

Both autism and eating disorders are characterized by cognitive rigidity or inflexibility in thinking patterns.

Cognitive flexibility, the ability to adapt thinking and behavior in response to changing conditions, is a skill that can be developed with appropriate therapeutic interventions. However, individuals with autism and eating disorders may struggle with cognitive flexibility in connected ways. Genetic predisposition can influence the level of cognitive flexibility in individuals. Studies have identified genes associated with cognitive flexibility, such as CPEB2-AS1, CPEB2, CRISPLD1, and TGFB1I1.

Social difficulties experienced by individuals with autism can significantly impact their eating habits. Mealtimes often involve social interactions, adherence to unspoken rules, and navigating complex social dynamics. Individuals with autism may struggle with these aspects, leading to feelings of anxiety, discomfort, or isolation during meals. These emotional vulnerabilities can increase the risk of using disordered eating behaviors, such as binge eating or purging, as maladaptive coping mechanisms to deal with anxiety or negative emotions related to social interactions and food. Difficulties in engaging in reciprocal conversations or interpreting non-verbal cues related to mealtimes can hinder their participation in social eating situations, leading them to eat alone, in secret, or avoid meals altogether.

While not all individuals with autism develop eating disorders, it is essential to raise awareness about the overlap between autism and eating disorders in order to create neurodiversity-informed eating disorder programs and improve the eating disorder treatment programs' understanding.

Examining the biological aspects of eating disorders in autism reveals shared genetic components. Certain genes involved in neurotransmitter regulation, reward systems, and appetite control have been implicated in both conditions. For example, variations in the oxytocin receptor gene (OXTR) have been associated with increased risk for both autism and anorexia nervosa. Additionally, brain imaging studies have shown differences in brain connectivity and activation patterns in areas involved in reward processing and executive functions, such as the prefrontal cortex, insula, and amygdala. These findings suggest potential shared neural pathways between autism and eating disorders.

It is crucial to acknowledge that not all individuals with autism will develop eating disorders, and the relationship between the two conditions is complex, and influenced by various factors. Environmental influences, societal pressures, co-occurring psychiatric conditions, and stressors can also contribute to the development of eating disorders in individuals with autism.

Recognizing the impact of sensory sensitivities, repetitive behaviors, and social difficulties on eating habits can guide interventions and support strategies. Taking a holistic approach that combines sensory accommodations, structured routines, social connections, and emotional support can help mitigate the risk of eating disorders and improve the overall well-being of individuals with autism. By raising awareness and fostering understanding, we can better support and empower individuals with autism who may also be dealing with eating disorders.