Special diets are diets which have been modified in some way to bring about specific healthcare benefits. Most special diets used to help people on the autism spectrum are ‘exclusion’ diets. This means you avoid or reduce foodstuffs which may harm you (such as additives in the additive-free diet). Other examples of exclusion diets are the gluten-free, casein-free diet, and the salicylate-free diet.
In some diets you have to exclude some foodstuffs but include others, such as the specific carbohydrate diet. This excludes complex carbohydrates (such as those found in rice and potatoes) and replaces them with simple carbohydrates (such as those found in bananas and squashes).
In practice, many diets share similar characteristics. For example, the Feingold diet is a mixture of the additive-free diet and the salicylate-free diet, while the specific carbohydrate diet incorporates elements of the gluten-free diet.
Some people think that diet is a key component of any intervention designed to help people on the autism spectrum. Some people also think that modifying the diet and the gastrointestinal system is necessary for the success of other treatments and therefore should come first.
Diets are sometimes combined with other therapies. For example, some people advocate following a particular diet, taking one or more dietary supplements and using detoxification techniques such as chelation.
The National Institute for Health and Care Excellence (2012) made the following observations on the use of exclusion diets for adults on the autism spectrum:
‘... there is very little evidence regarding safety and efficacy for exclusion diets ... for the treatment of autism.’
The National Institute for Health and Care Excellence (2013) made the following observations on the use of exclusion diets for children and young people on the autism spectrum:
“Do not use the following interventions for the management of core features of autism in children and young people: exclusion diets (such as gluten- or casein-free diets).”
Eating a healthy balanced diet is recommended for everybody in order to maintain good health. Anyone with a particular condition (in addition to or separate from autism) may be recommended to follow a special diet by a dietitian and this should be followed on an individual basis. For example, dietitians may recommend a gluten or milk exclusion diet for various gut problems.
Most special diets provide the same benefits for people on the autism spectrum as they do to people who are not on the autism spectrum. They do not appear to provide any additional benefits to people on the autism spectrum, according to a limited amount of research evidence of sufficiently high quality.
No evidence at all supports the use of most special diets (such as additive-free diets, the specific-carbohydrate diet, and the yeast-free diet).
Determining the benefits of other diets (such as the gluten-free, casein-free diet or the ketogenic diet) for people on the autism spectrum is not currently possible. We must wait until further research of sufficiently high quality has been completed.
We believe that some special diets (such as the Gut and Psychology Syndrome Diet) are scientifically unfeasible and potentially very harmful. For this reason, we strongly recommend that they are not used.
Because diets for people with autism constitute such a wide range of treatments it is not possible to provide a ranking for diets as a whole.
Please read our Disclaimer on Autism Interventions