Autism, Eating Disorders, and Digestive Issues

It’s no secret that digestive distress is a frequent complaint among autistic people with eating disorders.

In fact, research shows that up to 98% of people with eating disorders deal with functional gastrointestinal disorders (FGIDs)...and I’m willing to wager that a large chunk of those people are also autistic.

Whether this be nausea, cramping, bloating, constipation, diarrhea, or all of the above, gut issues are a pain in the a$$!

But why are digestive issues so common in the autism and eating disorder population? Based on the current research, there are two main factors:

1️⃣ Nervous System Activation

2️⃣ Gut-Brain Connection 

How The Nervous System Affects Digestion

The nervous system is the electrical information highway of the body. It’s at the foundation of not only how we experience stimulation, but it plays a key role in internal processes such as digestion.

You’ve likely heard of “fight-or-flight” mode and “freeze” mode before. They are responses to stress or danger, regulated by the autonomic (= automatic) branch of the nervous system.

Being autistic in a neurotypical world can cause one to live in a constant state of fight-or-flight mode. Not only do you pretend to be someone else to protect yourself from criticism and judgment, but you’re always on hyper-alert to ensure your environment is safe.

When you add an eating disorder to the mix, well that pretty much causes this autistic fight-or-flight mode to go on steroids! Lack of food is one of the greatest threats to your survival, meaning prolonged restriction causes your nervous system to perceive danger.

Being in fight-or-flight mode is energetically demanding, so the body can only sustain this state for so long until it shifts into freeze mode. Think: shutdowns, dissociating, and blanking out.

It goes without saying that digestion is your body’s LAST priority when your body believes you need to escape danger. I mean, evolution would have made a grave mistake if it supported you sitting on a bed of grass and finishing your sandwich if you were being chased by a tiger!

How do you get your body to digest food properly?

You create safety. Not only externally, but internally as well. A huge part of this is nourishing the gut-brain connection, which I explain below.

The Gut-Brain Connection to Digestive Issues

You've learned about how the nervous system impacts digestion, so what about the gut-brain axis? First, it’s helpful to define two key terms:

1️⃣ Functional gastrointestinal disorders (FGIDs): also known as disorders of the gut–brain interaction, are correlated to dysfunctional communication between the brain and gut. In scientific terms, dysfunction of the gut-brain axis.

2️⃣ Gut-brain axis: the two-way biochemical signaling that takes place between the gastrointestinal tract and your nervous system. The axis consists of multiple connections including your gut microbiome, your immune system, and your vagus nerve. Dysregulation in any of these pathways can result in digestive problems.

As explained above, autistic people and/or those with eating disorders tend to live in a constant state of fight-or-flight mode. When your body is in a stressed state, the systems that support healthy digestion go out of whack.

A huge component of this digestive dysfunction has to do with the communication between your brain and gut.

Neurotransmitters of which abnormal levels have been linked to neurodiversity and eating disorders – including serotonin and dopamine – are commonly associated with the brain…but did you know that these neurotransmitters are broadly found in the gut as well? In fact, nearly 95% of the body’s serotonin is produced in the gut and more than 50% of the body’s dopamine is synthesized in the gut!

What do these numbers mean?

That your mental health has a direct impact on your gut health and vice versa. If you sit down to a meal feeling anxious, this will undoubtedly manifest as digestive distress. On the flipside, if you consume a limited diet, the bacteria in your gut don’t get the nutrients they need. In turn, this “starved gut” impacts your brain, usually in the form of heightened anxiety and fear.

Now that you have this knowledge, you’re probably wondering: “Okay, but what do I do now?”

You take a holistic approach to food and eating. One that not only supports your physical health, but one that equally integrates understanding of the gut-brain connection.

If you don’t know where to start, I’ve got you covered! My cookbook Nourishing Neurodiversity contains recipes, tips, and tricks with the science in mind so you can (literally!) nourish your neurodiversity.