The Significance of Nutrition for Autism

Anna Hamer
Written by Anna Hamer

Autism spectrum disorder (ASD) is a neurological and developmental disorder that results from differences in the brain. Individuals with ASD exhibit unique behaviours, communication styles, social interactions, and learning abilities. The range and severity of symptoms can vary widely, which is why ASD is referred to as a “spectrum.” 90% of individuals with ASD experience atypical sensory reactions, characterised by both hyper- and hypo-reactivity to stimuli. This can translate into restricted and repetitive eating habits, to avoid sensory overwhelm. This leads to a preference for energy-dense, nutritionally deficient foods which can adversely affect their metabolism, leading to the accumulation of oxidative radicals, which detrimentally impacts their mental and physical well-being.

The importance of nutrition for autism can be attributed to three key factors:

Picky eating habits:

Did you know that up to 90% of children with autism exhibit picky eating habits? Sensory processing issues are common among individuals with autism, impairing their ability to correctly process sensory input. As a result, they may reject foods based on minor differences in flavour, odour, colour, or texture. This can lead to a limited diet comprised only of “safe” foods that are often bland, beige, and crunchy, sometimes even from specific brands. Such a restricted diet lacks essential nutrients, thereby compromising the functioning of the brain, immune system, gastrointestinal system, and detoxification pathways. Consulting with a nutritional therapist specialising in autism can help address these challenges and ensure adequate nutrition for individuals with autism.

The gut-brain axis connection:

Many individuals on the autism spectrum experience ongoing gut issues, such as constipation, diarrhoea, small intestinal bacterial overgrowth (SIBO), and yeast overgrowth. Research indicates a correlation between ASD and altered gut microbiota, which play a crucial role in metabolising and absorbing nutrients (De Angelis et al., 2013; Finegold et al., 2010). These gut issues can be linked to food sensitivities and intolerances. Imbalances in the gut microbiome can also negatively impact mood, concentration, and mental health. Including probiotic sources like yogurt and kefir, as well as prebiotic foods like bananas and onions, in the diet can help support a healthy gut microbiome.

Nutrient deficiencies:

As discussed, individuals with autism often experience nutrient deficiencies due to low intake and/or poor absorption. ASD children have inadequate intake of vitamin D, vitamin B12, vitamin C, calcium, zinc, and a lower consumption of dairy, compared to neurotypical children. In addition, certain genetic mutations common in autism can impair nutrient absorption and/or methylation. For instance, 98% of children with autism have a mutation of the MTHFR gene, which hampers the transformation of folate into methyl folate. This results in lower levels of essential antioxidants, such as glutathione and cysteine, making the body less resilient to stress and toxins, consequently affecting the immune system.

By addressing the challenges of picky eating, nurturing a healthy gut microbiome, and mitigating nutrient deficiencies, nutritional therapy can play a pivotal role in supporting individuals with autism. Ensuring adequate nutrition not only promotes their overall well-being but also helps optimise their cognitive and physical abilities. Collaborating with a specialised nutritional therapist can provide tailored guidance and support to enhance the health and quality of life for individuals with autism.

Anna Hamer is a trained nutritional therapist specialising in autism and selective eating. She offers virtual nutrition and lifestyle consultations via her website: or email: You can also follow Anna on instagram: @nutritionmate


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