Up to half of people with anorexia nervosa also meet the criteria for an autism diagnosis. According to research conducted at the Institute of Psychiatry, the place where I began my career, the figure is placed at around 35%. The link between anorexia nervosa and autism has been largely overlooked until now.
For many of the people I speak to, understanding this helps them make sense of their experiences.
It explains the time spent struggling with rigid food rules, overwhelming sensory reactions and a deep need for routine. It also explains why standard treatment hasn’t helped or could have made things worse. It. becomes clear that the problem was never really about weight or shape in the way it is assumed to be.
Why might autism and anorexia overlap?
Autistic women are often diagnosed late. They tend to mask social difficulties, follow the rules and can present as perfectionists.
But there are patterns that show up regularly. These include;
• Selective eating from a young age due to sensory sensitivities
• A need for sameness, which can lead to very rigid eating routines
• Difficulty sensing hunger or fullness (poor interoception)
• Social exhaustion and internalised anxiety
• Obsessive thinking patterns which can include fixations on food types, numbers on a scale, or nutritional rules.
• Intense focus on certain topics which could include diet, nutrition and food rules.
When selective eating affects the brain.
Selective eating is extremely common in both autism and anorexia. It can be a form of sensory self-protection. Certain textures, smells, or food combinations feel genuinely distressing or overwhelming.
Over time this limited dietary range can have an impact on nutritional status. Our brain chemistry relies on specific nutrients to make neurotransmitters and allow them to function effectively. If the diet is too restricted for too long, it’s easy to become depleted. That can reinforce anxiety, low mood, obsessive thoughts, and poor stress tolerance, creating a vicious cycle that makes recovery harder.
What about the gut?
It’s also worth recognising that many people with autism or anorexia can struggle with digestive symptoms. There can be bloating, constipation, reflux or general discomfort around eating. These gut issues often go under the radar but they can be central to the daily experience of food and nourishment.
The gut microbiome and the nervous system are closely linked and influence each other in both autism and eating disorders. Addressing digestive health can be an important part of recovery for many people.
Why standard ED treatment can fall short
If the eating disorder isn’t being driven by fear of gaining weight but by sensory overload or burnout then pushing body image therapy won’t work. It can make recovery harder as there is a misunderstanding as to what is driving the behaviour.
What helps instead?
• Sensory-friendly food options
• Gentle support for recognising body cues
• Structure, routine, and clarity
• Minimising overwhelm and reducing overall stress
• Support for gut function and digestive comfort
• Targeted nutritional support for neurotransmitter pathways
