Let’s Talk About Nutrition and Autism: Why It Matters

Nutrition can be a little more complex for individuals on the autism spectrum. Many people with autism have limited food preferences or are selective eaters, often due to sensory sensitivities around taste, texture, or smell. This can lead to low intake of important nutrients like vitamin D, vitamin B12, calcium, iron, zinc, magnesium, and protein—nutrients that are essential for immune function, bone health, cognitive development, and overall wellbeing.

Gastrointestinal (GI) issues are also common. Conditions like reflux, irritable bowel syndrome (IBS), and especially constipation are frequently reported. Constipation can be influenced by a combination of factors, including low fibre or fluid intake, limited physical activity, medication side effects, or slower gut motility. It's also worth noting that some individuals may experience differences in interoception—the ability to sense internal body signals—which can affect awareness of hunger, thirst, or the need to use the bathroom. This can make it harder to recognise and respond to signs of discomfort or fullness, and may further complicate nutrition and gut health.

Food sensitivities or intolerances can add another layer. Some individuals may have food chemical intolerances, allergies (such as to dairy, soy, or nuts), or need dietary adjustments like the low FODMAP diet for managing IBS symptoms. If these foods aren’t replaced with suitable alternatives, nutritional gaps can develop over time.

Medication is another important consideration. Some medications prescribed for individuals with autism or ADHD may reduce appetite and affect growth, while others may increase appetite or interfere with the absorption of specific nutrients.

The good news? With the right support, these challenges can be managed. A dietitian experienced in working with individuals on the spectrum can help address sensory needs, gut health, food variety, and nutritional balance—all while taking a compassionate, personalised approach.

Written by Shauna Gallant, APD