Reasons Why Autism Can Affect a Diet

Sensory difference can play a huge part: look, smell, taste, or the feel of food, as well as proprioception (body awareness), vestibular (balance) and interoception (awareness of internal states such as hunger or fullness).

Desire for Sameness
We know that individuals on the spectrum are likely to have cognitive rigidity and the ‘desire for sameness’ and this may result in an adherence to particular routines or rituals around food. Whole categories of foods may be refused, typically meat, fruit and/or vegetables. This may be because they contain examples of foods that are visually very different from one another. The child who has difficulties forming categories of objects or generalising within categories is then likely to stick to those groups of foods that look very similar. In addition, when a child is anxious, cognitive rigidity will increase, making the expansion of food categories much harder.

Anxiety, Disgust and Contamination
Anxiety about what will happen during or after eating, such as whether the food will be ‘okay’, being sick or choking and in eating situations outside of home, is common in individuals with Autistic Spectrum Condition. Additional disgust and contamination reactions are also common.

An Example of How Autism Affects Diet

Joanna Grace is an international special educational needs and disabilities consultant and founder of The Sensory Project.

Joanna is on the Autistic Spectrum and often writes about her experiences. Below is her explanation about her restricted diet and food choices.

“Earlier this week my Mum was remembering to me the limited diet I ate as a child.
It is common for children with autism to eat a restricted diet.

I thought I'd try to explain what was going on, but it is harder than I realised.

My autistic brain has a tendency to think in black and white. This is right or wrong, good or bad, safe or dangerous.

Back then I had a list of foods in my head that are safe. They mostly looked like those pictured below. I still eat a lot of these. A lot. But I also now eat foods I previously would not have considered safe. Basically I still have a safe list and a dangerous list. It's just the length of these lists have changed.

How did foods make the journey from the dangerous list to the safe list?
  • Without pressure.
  • With exposure.
  • Repeated opportunities.
  • Small amounts to test.
  • Some came in by the backdoor. For example, I now eat onions because I ate pickled onion flavour crisps.

  • I would find it hard to articulate how deep the panic goes when you eat a food that isn't safe. It is a feeling I can still feel today and I am not keen to think about it.

    A child in a state of panic or terror does not benefit from people being cross with them or attempting to force the situation.

    My original safe foods were sweets or very strong salty flavours, mostly marmite or salt and vinegar crisps. Packaged completely wrapped items felt safer than homemade stuff.

    Trauma specialists talk about different types of stress in the brain. Big catastrophic events obviously have a huge chemical impact on the brain. But people who experience regular low levels of trauma can have it effect the chemicals in their brain and over time this can shape the brain. People with autism can find social contact stressful. In childhood an awful lot of social contact is expected as you spend six hours a day with your peers (I would never do that now!).

    If you have ever experienced something traumatic, you probably reached for sugar in some way afterwards as it helps your brain rebalance its chemicals.

    Constant small low levels of sugar could have been helping me maintain hormone levels in my brain.

    The strong flavours are a thing too. Masticating, biting and chewing is calming for everyone. Strong messages in the mouth amplify this. I ate hard crunchy things. Bitter, sharp, tangy things. Marmite. All of these were calming. Countering some of the natural heightened anxiety/awareness levels experienced by people with autism.”

    Here is a link to Joanna’s Facebook page.

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