Special diets are diets which have been modified in some way to bring about specific healthcare benefits. Most special diets used to help autistic people 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 autistic people. 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 autistic adults:
‘... 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 autistic children and young people:
“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 autistic people as they do to people who are not autistic. They do not appear to provide any additional benefits to autistic people, 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 autistic people 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
Some special diets may be recommended for people with specific health problems and/or nutritional requirements. For example,
All special diets are diets which have been modified in some way to bring about specific healthcare benefits. For example,
Claims
There have been various claims for different special diets. For example,
Special diets are diets which have been modified in some way to bring about specific healthcare benefits. Most special diets used to help autistic people are ‘exclusion’ diets. This means you avoid or reduce foodstuffs which may cause specific symptoms (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.
It is important to remember that small quantities of many ingredients such as wheat and milk are used in many different foods. For example, gluten or its derivatives can appear in a wide range of things including biscuits, nuggets and chips, as well as some flavourings.
Some people think that diet is a key component of any intervention designed to help autistic people. 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 following is a list of some diets which have been reported to be beneficial to autistic people.
Many of these 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.
The cost of following a special diet depends on things like the type of diet, whether the whole family is following the diet, whether you are buying ready-made meals or making them yourself.
For example, the major cost of following the gluten-free casein-free diet is buying gluten -free and/or casein -free foodstuffs, which are often more expensive than foodstuffs which contain these things. According to Stevens and Rashid (2008), gluten-free products were on average 242% more expensive than regular gluten containing products
In the UK, it is sometimes possible to obtain prescriptions for foodstuffs for patients in specific circumstances, such as when they have a confirmed diagnosis of coeliac disease but not if they have autism.
Most special diets are designed to be followed seven days a week for months or years. The amount of time you need each week will depend on the type of diet and whether you are making all of the meals yourself. In addition, it takes time to check the labels of foods you buy to ensure that they do not contain restricted foodstuffs.
For example, some proponents of the gluten-free casein-free diet recommend a trial period of three or four months. If it has not worked within that time they say it is unlikely to do so. However some researchers also suggest that the most reliable trial results are obtained after you have been on the diet for more than a year.
However, most dietitians recommend that a 2-6 week trial of an exclusion diet followed by reintroduction is adequate to identify if a dietary change has been beneficial. This is backed up by the 2011 NICE guideline food allergy in under 19s: assessment and diagnosis that recommends “if non-IgE-mediated food allergy is suspected, trial elimination of the suspected allergen (normally for between 2–6 weeks) and reintroduce after the trial. Seek advice from a dietitian with appropriate competencies, about nutritional adequacies, timings of elimination and reintroduction, and follow-up.”
There are many potential risks in withdrawing normal or regular foods from individuals, but especially young children.
Some autistic people are faddy eaters. They already have a less healthy and less varied diet than other people. Restricting what they eat even further may reinforce those rigid eating patterns. It may also increase their social isolation (because they can’t eat the same food as their friends at parties or restaurants).
In the long-term special diets could lead to health problems if they are not carefully balanced. For example, according to Marí-Bauset et al (2015),
“The combination of food selectivity and restrictive diets can make it difficult to achieve an adequate diet, consequently resulting in an excessive intake of certain foods and/or deficiencies and malnutrition due to insufficient amounts of other foods. In turn, inadequate intakes may lead to the development of chronic and degenerative conditions that tend to appear in the third or fourth decade of life (cardiovascular disease, high blood pressure, diabetes, dyslipidemia and osteoporosis, among others) or even earlier, in the case of menstrual disturbances, sleep apnea, and psychosocial disorders.”
Notes: diabetes, condition characterised by high blood sugar levels; dyslipidemia, an abnormal level of fatty acids; osteoporosis, brittle or fragile bones; sleep apnea, temporary suspension of breathing.
There are some potential hazards associated with specific diets. For example,
There are no known contraindications (something which makes a particular treatment or procedure potentially inadvisable) for most diets. However, some diets can be very challenging and difficult to adopt, especially for some autistic people. For example, according to Evangeliou (2003),
“The classic ketogenic diet is very restrictive and requires a large amount of dietetic involvement in terms of calculations, monitoring, patient support, and motivation from the family to adhere to the diet; consequently, it is difficult to adapt for children with [learning disabilities].”
Autistic people or their carers who have concerns about their or their child’s diet should seek advice from a responsible health professional such as their health visitor or GP. This may lead to a referral to a dietitian, in particular one with experience of working with autistic people.
The supply and availability of the ingredients required for special diets varies enormously between different diets and sometimes between different countries. For example, obtaining gluten-free or casein-free ingredients can be difficult in some countries.
The quality of special diets varies enormously depending on the diet, the ingredients used, and how rigorously you follow the diet. Most specialist diets are unregulated and uncontrolled, since anyone can choose to follow them.
Various support groups exist which may be able to advise you on how to follow specific diets and there are usually resources (such as books or DVDs) which may also instruct you on how to follow those diets.
However, if you are contemplating following a special diet, you should seek advice from a paediatrician, GP or dietitian. The British Dietetic Association has information about qualified dietitians in the UK.
There are no formal, internationally validated registered qualifications for people using most special diets for autistic people, since any individual, parent or carer can choose to implement the diets.
However, if you are contemplating such a significant change of diet you should definitely seek advice from a qualified medical practitioner, paediatrician and/or dietitian.
The British Dietetic Association has information about qualified dietitians in the UK.
The history of the use of special diets (dietetics) can be traced as far back as the writings of Homer, Plato and Hippocrates in ancient Greece. For example, Hippocrates is reported to have said “Let food be thy medicine and medicine be thy food.”
According to the British Dietetic Association website, accessed on 27 September 2016,
“The earliest dietary observations in hospitals go back to St Bartholomew’s Hospital in 1687. Evidence of the first therapeutic diet comes from the Radcliffe Infirmary, Oxford, in 1837 when observers noted 'the diet which suffering and exhausted nature sometimes requires after operations (mutton chops)'. However dietetics really started from the middle of the nineteenth century when Florence Nightingale observed the importance of diet and nutrition to convalescence from the wars at that time.”
The history of particular diets varies from diet to diet. For example, the specific carbohydrate diet was originally developed in the 1950's by Dr. Haas, a New York pediatrician, as a diet for coeliac disease. It was subsequently taken up and promoted by Elaine Gottschall, a New Jersey biochemist, to treat her daughter, who suffered from ulcerative colitis. The diet has since been taken up as a treatment for other conditions, including autism.
The gluten-free, casein-free diet, on the other hand, was developed in the early 1980s. A number of researchers, including Herman and Panksepp, noted the similarities between the effects of opioids and the symptoms of autism. Panksepp suggested that autistic people might have high levels of opioids in their central nervous systems caused by undigested peptides. Thereafter some professionals and parents began to use the gluten-free casein-free diet in order to eliminate these peptides.
Most special diets provide the same benefits for autistic people as they do to people who are not autistic. They do not appear to provide any additional benefits to autistic people, 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 autistic people is not currently possible. We must wait until further research of sufficiently high quality has been completed.
This section provides details of other publications on this topic.
You can find more publications on this topic in our publications database.
If you know of any other publications we should list on this page please email info@informationautism.org
Please note that we are unable to supply publications unless we are listed as the publisher. However, if you are a UK resident you may be able to obtain them from your local public library, your college library or direct from the publisher.
This section provides personal accounts of special diets for autistic people.
Personal accounts can be useful sources of information about the intervention but are not as scientifically valid or reliable as research trials. This may be especially true where the accounts are published by an organisation which might gain a financial advantage from the take-up of the intervention.
Please note that the views expressed in these personal accounts do not necessarily represent our views.
There are numerous personal accounts of the benefits of different special diets as treatments for some of the problems facing autistic people.
The 2011 NICE guideline recommends – “Do not use the following tests in the diagnosis of food allergy: vega test, applied kinesiology, hair analysis, IgG testing”, and that “If food allergy is suspected (by a healthcare professional or the parent, carer, child or young person), a healthcare professional with the appropriate competencies (either a GP or other healthcare professional) should take an allergy-focused clinical history tailored to the presenting symptoms and age of the child or young person.”