Diets for Autism

  • Dietary Intervention for Autism

    By Julie Matthews      

                Dietary intervention can be a powerful healing tool that can complement behavioral, speech, occupational, and other treatments recommended by your autism pediatrician.  When the child’s internal factors and physical symptoms are addressed, his attention and focus improve, opening up his mind to therapeutic learning.

    Choosing foods to add and remove from the diet is thus the first step to improving the health and well being of children with autism.  Certain food substances (most notably, gluten and casein, the principal proteins in wheat and cow’s milk, respectively) are known to be problematic for many children with autism[i] —and other foods, rich in healing nutrients, are unquestionably beneficial.  Attention to these factors can help balance biochemistry, effect systemic healing, and provide relief of autism symptoms.




    A healthy diet and good digestion are essential for good health.  For many children, the physiological and behavioral symptoms of autism can be aggravated by impaired digestion and GI health.  One research study concluded that “unrecognized gastrointestinal disorders…may contribute to the behavioral problems of the non-verbal autistic patients.”[ii]

    Poor digestion can lead to a condition known as leaky gut (increased intestinal permeability), which can result in insufficient absorption of nutrients, inflammatory responses to foods that are not broken down, and an overload of the detoxification system.  Adequate nutritional status, essential to proper biochemical and brain functions, requires both the consumption of nutrient-dense foods and proper digestion to break down and absorb those foods.  Additionally, the response to certain foods, such as gluten and casein, can create an opiate or inflammatory reaction that can affect the brain.





    There are several autism diets, and deciding how to begin nutritional intervention can seem overwhelming.  Because everyone is unique, a diet that helps one child may not be the best for another.  Each child has particular biochemistry, immune functioning, genes, environment assaults, and eating preferences.

    In my book, Nourishing Hope for Autism, I discuss thirteen different diets that are recommended for autism.  While each diet has merit, some include advanced components that are best supported by an experienced practitioner and not necessarily required to get started.  In this article, I will explain the top three diets for autism—these include the most immediately helpful dietary principles and practices, and there is much literature and community support to aid their successful implementation.


    Gluten-Free Casein-Free Diet (GFCF)


                When parents decide to “do diet,” they typically begin with the GFCF diet.  There are many good books and websites about it, and the food marketplace is increasingly GFCF friendly.  It entails the omission of all gluten- and casein-containing foods.  Gluten is a protein found in wheat, rye, barley, spelt, kamut, and commercial oats; and casein, a protein found in dairy.

    If the protein is not properly broken down during digestion, it can form opioids (opiate or morphine-like compounds). The properties of gluten and casein can lead to digestive problems such as diarrhea, constipation, gas, and bloating, as well as foggy thinking and inattentiveness for many children with autism.

    Most of the foods containing these offending proteins are easy to identify.  While following the GFCF diet, you’ll need to avoid any breads, crackers, pasta, or bakery items made with wheat and other gluten grains, and all dairy foods, such as milk, cheese, butter, yogurt, and cream.  Some sources however, can be sneaky, as some foods contain offending ingredients that are not apparent, such as:

    • Soy sauce (except gluten-free soy sauce)
    • Potato chips and fries (often dusted with gluten during processing, although it may not be listed on the label; ensure they are gluten-free by checking with the company)
    • Malt (derived from barley)


    When beginning the GFCF diet, be careful not to introduce a bunch of GFCF junk foods, such as cookies, candy, and chips.  Even though they don’t include gluten or casein, the sugar can feed yeast, imbalance blood sugar, and disregulate energy.  Remember, diet is more than just the removal of offending foods—attention must be placed on ensuring healthy and nutritious food intake.  The GFCF diet is the best one to follow when first beginning nutritional intervention for autism.


    The Specific Carbohydrate Diet (SCD)


                SCD involves the removal of all complex sugars—everything except raw honey and the sugar naturally occurring in fruits and vegetables—including the removal of maple syrup, cane sugar, agave nectar, brown rice syrup, and more.  SCD also removes all grains and all starches, including potatoes and sweet potatoes.  This diet allows meat, fish, eggs, nuts and seeds, certain beans, all non-starchy vegetables, and fruit.  This is not a low carbohydrate diet but a specific carbohydrate diet that relies on non-starchy vegetables, fruit, honey, and certain beans for carbohydrates.

    This is the second most commonly applied autism diet. It is very helpful for those who have inflammatory bowel conditions and chronic diarrhea, although it can help constipation, too.

    SCD aims to reduce gut inflammation and avoiding foods that require carbohydrate-digesting enzymes, which are often in short supply.ii             Because it is more restrictive than the GFCF diet, parents don’t usually begin dietary intervention with SCD, except in some cases where there is a significant inflammatory gut condition.  SCD is often applied when the GFCF diet has not been enough and digestive problems still remain, or if someone wants to further evolve the diet to see additional benefits.


    The Body Ecology Diet (BED)


    BED is an anti-candida diet focused on clearing up yeast and dysbiosis (imbalance of microbes in the gut).  BED incorporates the principles of proper food combining, maintaining acid/alkaline balance with low acid-forming foods, limiting sugars and starches, providing easily digestible foods and fermented foods, and enacting other solid nutritional recommendations to clear up candida overgrowth and support health.  BED includes many fermented foods, such as raw sauerkraut and other cultured vegetables, and kefir and yogurt (non-dairy versions when casein is not tolerated).

    BED allows only a few grains, such as quinoa, millet, buckwheat, and amaranth (when properly soaked)—restricting more starches and grains than the GFCF diet.  In addition to being gluten free, BED is rice free, corn free, and soy free.  It allows casein, but can be done casein free.  If your child has candida, BED may be the diet for you.

    Like SCD, this diet is beneficial for reducing dysbiosis and restoring good flora balance in the gut.  However, these two diets rely on very different underlying principles.  SCD removes certain sugars and all starches, while BED removes all sugars and certain starches.

    Problematic Food Substances


    While following any autism diet, it is important to monitor and moderate the intake of certain additional food-based substances.  Common problematic food substances are discussed below:


    Phenols and Salicylates


    A phenol is an organic compound with an aromatic/benzene ring, and can be neither naturally occurring, as in salicylates, or chemically manufactured, as with artificial food additives.  These artificial colors, flavors, and preservatives are created from petroleum derivatives and have been found in a recent study to cause hyperactivity in children.[iii]

    Salicylates are a type of phenol that act as natural pesticides in plants but are not harmful to humans because we have an enzyme (phenolsulfotransferase, or PST) that breaks them down.  Some foods high in salicylates are red grapes, apples, berries, almonds, and honey.  When children consume salicylates, they can get a wide range of symptoms, including hyperactivity, fatigue, diarrhea, other negative gut symptoms, sleeping challenges, aggression, and irritability. The Feingold Diet is the most basic diet that restricts salicylates and phenols.


    Amines and Glutamates


    Amines are phenolic-like substances and can affect children similarly to salicylates.  Amines are derivatives of ammonia, and exogenous forms (originating outside the body) are found in certain foods.  Biogenic amines in foods can be produced by the breakdown of amino acids; therefore, well-cooked (easily digestible) foods, such as slow-cooked meats, broths, and fermented foods, often contain high amounts of amines.

    Glutamate is the most abundant excitatory neurotransmitter in the brain, and is involved with learning and memory.  While this neurotransmitter is important, too much glutamate, especially from food additives, can be neurotoxic[iv] [v] and can prevent proper functioning of the body’s natural calming mechanism, as well as causing hyperactivity, shortness of breath, headaches, anxiety, and other problems.

    Glutamates can be derived from certain foods in which they occur naturally, as well as from MSG and other additives containing MSG, such as autolyzed yeast and hydrolyzed vegetable protein.

    The Failsafe Diet removes phenols and salicylates (more thoroughly than the Feingold Diet), as well as amines and glutamates, including food-based forms.  Failsafe also removes additional food additives, including propionic acid, which is used in preserving bread and dairy products.




    Oxalates are found in foods such as spinach and nuts (as well as being produced in the body).  Oxalate binds with calcium and when it encounters damaged tissue (and other conditions) can form crystals.  Oxalates crystals are sharp; the same that are responsible for certain forms of painful kidney stones.  Oxalate crystals can be inflammatory and damaging to children’s delicate biochemistry.  Normally, a healthy gut will not absorb too many oxalates from the diet, because they are metabolized by the good bacteria in the gut or they bind to calcium and are excreted in the stool.[vi]

    If a diet is very high in oxalates—for example, if it contains high amounts of almond and nut flours—and if gut inflammation, dysbiosis, and pain are problems, one might consider a trial of a low-oxalate diet.


    You Can Do Diet


    You may be thinking, “My child is picky and very inflexible with eating new foods.  I’m never going to be able to get him to eat anything other than wheat and dairy—never mind anything ‘healthy.’”  You may also be wondering if an autism diet will really help your child’s symptoms.

    I appreciate these concerns.  I have had some very picky eaters in my nutrition practice—many children ate only bread and dairy; others subsisted on just pancakes and fries.  However, it’s worth trying diet because once the child gets past the cravings (in a few days to a few weeks), they often expand their food choices dramatically.  Once they begin an appropriate diet (and the cravings diminish), children begin eating more vegetables (or meat)—often for the first time.  Now, there are some children who are very self-limiting, and it takes time to change their diets—but keep at it.  Sometimes, as occupational therapy or sensory integration begins to address food textures, a child begins to expand more.

    Until then, get creative and make foods crunchy or smooth based on your child’s preferences.  Begin to add new food options, such as gluten-free pasta, before removing existing foods.  Have healthy snacks within the diet of choice on hand and remove all ‘junk foods’.

    As a parent, you have the option of correcting imbalances in your child’s body through nutrition – a very powerful healing tool that can complement behavioral and other treatments that help children make progress.

    Any child’s diet can change.  It may take time and require great patience, but you can make improvements.  It’s crucial that parents believe it’s possible for their children to change and improve.  By envisioning the changes, you project a positive image that is important for your child and the success of your overall efforts.  I’ve never known a child who did not benefit from dietary intervention, and I’ve never seen a child’s diet that did not (with proper attention) eventually expand and improve.



    Julie Matthews is an internationally respected Certified Nutrition Consultant specializing in autism spectrum disorders.  She is an expert in applying nutrition and diet to aid digestive health and systemic healing, and is the author of the award-winning book Nourishing Hope for Autism, a comprehensive guide to nutritional and dietary intervention for autism.  Julie speaks at biomedical autism conferences in the U.S. and abroad, writes for autism publications, and has a private nutrition practice in San Francisco.  For more information, visit her website:



    [i] Knivsberg AM, Reichelt KL, Nodland M.  (2001) Reports on dietary intervention in autistic disorders.  Nutritional Neuroscience, 4(1):25-37.

    [ii] Horvath K, Papadimitriou JC, Rabsztyn A, Drachenberg C, Tildon JT.  Gastrointestinal abnormalities in children with autistic disorder.  J Pediatr.  1999 Nov;135(5):559-63.


    [iii] McCann D , Barrett A, Cooper A, et al.  Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomized, double-blinded, placebo-controlled trial.  Lancet.  2007:370(9598):1560–156.7.


    [iv] Manev H, Favaron M, Guidotti A, Costa E.  Delayed increase of Ca2+ influx elicited by glutamate: role in neuronal death.  Mol Pharmacol.  1989 Jul;36(1):106-12.


    [v] Olney JW, Sharpe LG.  Brain lesions in an infant rhesus monkey treated with monsodium glutamate.  Science.  1969 Oct 17;166(903):386-8.


    [vi] Campieri C, Campieri M, Bertuzzi V, et al.  Reduction of oxaluria after an oral course of lactic acid bacteria at high concentration.  Kidney Int.  2001 Sep;60(3):1097-105.

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