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Are there special diets for autism?

Autism diet and supplements: What parents should know

Updated: August 11, 2023 · 7 Minute Read

Rashelle Berry, MPH, MS, RDN, LD

Reviewed by:

Rashelle Berry, MPH, MS, RDN, LD


  • Though behavioral and educational interventions are found to be most effective for autistic children, many families turn to complementary and alternative methods
  • While the American Academy of Pediatrics does not currently endorse the use of dietary intervention for autism (such as gluten-free, casein-free, ketogenic, probiotics, and dietary supplements), most autism parents report that their children are using an alternative diet
  • Alternative diets and supplements are risky and might lead to nutritional deficiencies, increased stress, and financial burdens for families
  • Making changes to your child’s diet requires careful planning —you should always consult your child’s doctor before making any changes to your child's diet

We often get questions from autism parents about diet and supplements, so we've put together the below guide to help. 


While the American Academy of Pediatrics does not support the use of alternative diets as a treatment of autism, more than 80% of parents with an autistic child report using some form of dietary intervention1 such as supplements, gluten-free diet, casein-free diet, ketogenic diet, and probiotics. 


Why are dietary interventions for autism so popular? 

Over 70% of autistic children have gastrointestinal (GI) symptoms, such as diarrhea, constipation, and abdominal pain. It can be difficult for children with autism and language delays to show their discomfort and communicate symptoms. They might act out or have problems sleeping instead. 


To make things even more challenging, children with autism often have feeding problems such as selective eating (see A parent’s guide for picky and selective eaters). Children with a limited diet can experience issues such as constipation and intestinal microbiota (more on microbiota later in the article)!  


What is the most common alternative treatment for autism?  

The gluten-free and casein-free (GFCF) diet is one of the more commonly implemented diets by parents. Gluten is a mixture of proteins found in wheat and related grains such as barley and rye as well as in many processed and prepackaged food products. Foods that contain gluten can also be used to alter the taste and texture of foods. Gluten-free diets are often combined with a casein-free diet. Casein is a protein found in dairy products. 

gluten free and casein free diets for autism

For most children, gluten is completely harmless. An exception is if the child has celiac disease, where gluten triggers the release of antibodies which attack the small intestine and makes it hard for kids to absorb the nutrients needed to grow and thrive. Gluten-free diets are the first-line treatment for celiac disease. 


It’s common for autism parents to remove foods that contain gluten and casein in an attempt to reduce symptoms of autism, not on the basis of an allergy, lactose intolerance, or celiac disease. Despite the wide-spread use of GFCF as an alternative diet in autistic children, research does not support it as an effective treatment of autistic related-symptoms.2


Is it safe for autistic children to try alternative diets?

It’s risky. The first step is to talk with your pediatrician. If your child is experiencing GI symptoms or changes in their behavior, your doctor will want to rule out any possible underlying medical conditions such as a toothache or allergies. 


Once any underlying medical conditions have been ruled out, behavioral and educational interventions are found to be most effective for children with autism (See The complete guide to feeding therapy or The complete guide to ABA). 


With so many autistic children experiencing GI symptoms and the broad impact on day-to-day life, many parents have looked for alternatives to the recommended behavioral interventions to help their child. Here are a few risks you need to consider:


You can actually hide medical conditions before they are diagnosed. If you are concerned your child has a gluten intolerance, it is important to see your child’s doctor prior to making any dietary changes. Removing gluten from the diet before testing for celiac disease can alter the test results and make diagnosing more difficult. 


Your child might not be getting a complete diet. Healthcare professionals warn that because so many foods contain gluten and casein, restricting it can affect your child’s nutrition. Many children with autism also have severe picky-eating disorders and implementing further restriction on their diets can be harmful to their overall nutritional intake. See The autism parent’s guide to a complete diet.


Trendy diets are expensive. Alternative diets can also put a dent in your wallet —for example, gluten-free products are found to be much more expensive (by almost 200%, yikes!).3


Food products that are gluten-free does not mean it is healthy. Almost 90% of gluten-free foods marketed for children are actually quite unhealthy because of their sugar content.3 This is especially important for children with autism who are already more likely to be overweight or obese. 


Should autistic children take vitamins and other dietary supplements? 

Most doctors and families would say yes. Because feeding problems are so common in children with autism, it is important to have their nutritional intake monitored as part of their health supervision check-ups. While severe nutritional deficiencies (such as rickets or scurvy) are rare, they can be seen in children with severe food aversions and require immediate medical interventions. 


It’s common that autistic children need more vitamin D, calcium, and fiber. A registered dietician can provide information about supplementation. If it is determined your child would benefit from supplementation due to poor vitamin D or calcium intake, it is important to discuss the correct dose for your child’s age. 


The use of probiotics in children with autism is a trending topic. The gut microbiome consists of trillions of microorganisms that are mostly beneficial to the human body. These microorganisms help stimulate the immune system, break down potentially toxic foods, and even produce certain vitamins and amino acids.4 Probiotics are live microorganisms that can be found in yogurt, fermented foods, and dietary supplements. Researchers are currently looking into the possible benefits of targeting the gut microbiome using probiotics in autistic children. Though the research is limited, recent studies have found that the composition of gut microbiota is largely different in autistic and non-autistic children.5


Could probiotics be harmful for children?

There are certain medical conditions, such as people with weakened immune systems, where the use of probiotics is not safe.  There are many different probiotics and very little information about appropriate dosing and strains suitable for children.2


Probiotics are categorized as supplements and not food which means they are not regulated by the Food and Drug Administration. Unless the supplement company voluntarily discloses information on quality, such as carrying the USP (U.S. Pharmacopeial Convention), a probiotic may not contain the amounts listed on the label or even guarantee that the bacteria are alive and active. 

alternative diets for autism facts


Parents should always keep in mind that dietary interventions have risks and to always seek nutritional counseling from your child’s healthcare team.

Dive Deeper

Article References

  1. Lange KW, Hauser J, Reissmann A. Gluten-free and casein-free diets in the therapy of autism. Curr Opin Clin Nutr Metab Care. 2015;18:572–575.
  2. Karhu E, Zukerman R, Eshraghi R et al. Nutritional interventions for autism spectrum disorder. Nutr Rev. 2019;78(7):515-531. doi:10.1093/nutrit/nuz092
  3. Lee AR, Wolf RL, Lebwohl B, Ciaccio EJ, Green PHR. Persistent Economic Burden of the Gluten Free Diet. Nutrients. 2019;11(2):399. Published 2019 Feb 14. doi:10.3390/nu11020399
  4. The Microbiome. The Nutrition Source. Published 2022. Accessed July 19, 2022.
  5. Xu M, Xu X, Li J, Li F. Association Between Gut Microbiota and Autism Spectrum Disorder: A Systematic Review and Meta-Analysis. Front Psychiatry. 2019;10:473. Published 2019 Jul 17. doi:10.3389/fpsyt.2019.00473
  6. Gogou M, Kolios G. Are therapeutic diets an emerging additional choice in autism spectrum disorder management? World J Pediatr. 2018;14:215–223. 
  7. Elder JH, Shankar M, Shuster J, et al. The gluten-free, casein-free diet in autism: results of a preliminary double blind clinical trial. J Autism Dev Disord. 2006;36:413–420.
  8. Winburn E, Charlton J, McConachie H, et al. Parents' and child health professionals' attitudes towards dietary interventions for children with autism spectrum disorders. J Autism Dev Disord. 2014;44(4):747-757. doi:10.1007/s10803-013-1922-8
  9. Critchfield JW, van Hemert S, Ash M, Mulder L, Ashwood P. The potential role of probiotics in the management of childhood autism spectrum disorders. Gastroenterol Res Pract. 2011;2011:161358. doi:10.1155/2011/161358