Autism Spectrum Disorder: Diet Tips for Children

Diet tips for children with autism spectrum disorder

Children with autism spectrum disorder have more feeding problems and they also eat a significantly narrower range of foods.

There is anecdotal evidence regarding the association between dietary changes and improvement in behaviour, communication and learning in children with autism spectrum disorder. However, there is a lack of quality evidence to make recommendations for any particular diet to treat autism spectrum disorder.

Nevertheless, studies have shown that more than half of the children with autism spectrum disorder have more feeding problems compared to children without autism. Feeding problems may present later, at around 2 years of age, when the child’s feeding style changes. They also eat a significantly narrower range of foods. This can include specific preferences for texture, temperature, colour and smell of foods as well as the mealtime environment, resulting in distress at trying new foods.

Children with autism spectrum disorder often have preference for crunchy foods and refuse soft, mushy, sticky and chewy foods. “Although most children with autism spectrum disorder may be of normal weight and height, their restricted diets put them at risk of nutritional deficiencies,” says the Nutrition and Dietetics Department at KK Women’s and Children’s Hospital, a member of the SingHealth group.

Hence, parents should seek advice promptly from a multidisciplinary feeding team including the speech language therapist, occupational therapist and dietitian if they notice feeding problems, and not wait till their child’s growth falters.

Diet tips for children with autism spectrum disorder

Common diets advocated to manage autism spectrum disorder are listed below. If parents wish to start their child on any of the diets below, this should be done in consultation with the doctor and dietitian to ensure that the diet is nutritionally adequate to support the child’s optimal growth and development.

The diet should only be trialled for a definite period of time, with an independent assessor for improvements in behaviour, communication and learning (e.g. for 3 months with the child’s teacher as an independent assessor) after which the diet should be discontinued if there are no significant improvements.

Gluten-free, casein-free (GFCF) diet

The gluten-free, casein-free diet is not a medically proven diet therapy for children with autism spectrum disorder. Restricting gluten and casein from a child’s diet can significantly affect the child's calcium, vitamin D and protein intakes, which can affect his or her physical and mental development, as well as bone health.

Gluten and casein are the main types of protein found in wheat and dairy products. Excluding wheat-containing products and milk and dairy products can compromise calorie and nutritional intake if appropriate substitutes are not provided.

Proponents of this diet hypothesise that children with autism spectrum disorder need to avoid gluten and casein for the following reasons:

they have gastrointestinal problems, which affect their ability to properly digest gluten and casein,
they have so-called “leaky guts” in which their intestines are more porous than other children, resulting in the incompletely digested gluten and casein “leaking” into the intestines and causing behavioural, communicative, social and cognitive difficulties, and
they have problems with their immune system, resulting in allergic reactions to gluten and casein.

For parents who wish to trial this diet, please consult with the doctor and dietitian before starting on it.

If parents of children with autism spectrum disorder are keen to trial the exclusion of food additives, they can do so as there is little effect on the nutritional quality of the diet and is in line with general healthy eating guidelines. However, they should weigh the benefits of following such a diet against limiting their child’s range of food choices further, as children with autism spectrum disorder already tend to self-limit their ranges of food consumed.

Exclusion of phenolic compounds and salicylates for autism spectrum disorder

The exclusion of these compounds is based on the hypothesis that these can contribute to hyperactivity.

Foods commonly excluded are:

cheese
chocolates
yeast extract
some food colourings
fruits such as apples, avocados, blueberries, kiwi fruit, grapes, plums, strawberries,
vegetables such as cauliflower, cucumber, mushrooms, radish, eggplant, spinach, tomato, broccoli
nuts such as peanuts, pistachios, almonds

What is the impact of excluding phenolic compounds and salicylates on autism spectrum disorder?

More research is required on the effectiveness of the diet. Without suitable alternatives to replace foods high in phenolic compounds and salicylates, children with autism spectrum disorder may compromise on energy or nutrient intake. Moreover, salicylates are found naturally in fruits and vegetables, and restricting these can lead to constipation. Hence, these exclusions are not recommended.

Supplements for autism spectrum disorder

Proponents of using high doses of individual vitamins and minerals hypothesise that this is necessary due to metabolic and biochemical abnormalities. Most recommended dosages exceed the safe upper limit for children and even adults, and little is known about the long-term effects of high doses of supplements in children.

Multivitamin and mineral supplementation: Vitamins and minerals which are popularly advocated include vitamins A, B and C, folate, magnesium and zinc. There is insufficient evidence to support the recommendation of specific vitamins and minerals for the treatment of autism spectrum disorder. However, usage is appropriate when dietary intake is insufficient to meet recommended dietary intakes.
Fish oil and other fat supplements: It has been suggested that omega-3 deficits or imbalances in omega 3 to omega 6 fat ratio is linked to the difficulties associated with autism spectrum disorder. There is little evidence to support the use of omega-3 supplementation to improve the symptoms of autism spectrum disorder.
Probiotic supplements: It has been hypothesised that the altered gut microbiota in children with autism spectrum disorder is linked to gastrointestinal symptoms such as constipation, diarrhoea and bloating. However, there is limited evidence available to suggest probiotics can benefit gastrointestinal symptoms or behavioural challenges in children with autism.

If parents are keen to supplement omega-3 intake due to fussy eating behaviour, refer to Brain Foods for Children: Fish and DHA for details.

Ref: N18

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