The GFCFKids Diet Survey - Preliminary Results

Posted in Additional Information

The purpose of the GFCFKids Diet Survey is to gather and process information about dietary intervention, chiefly in the form of Gluten-Free and Casein-Free diet, for patients on the autistic spectrum.

The survey is Internet-based. It is a by-product of the work carried out by the GFCF Diet Support Group, and will be updated as more data is collected.

The survey is the result of cooperation between two volunteers:

Jørgen KlavenessIdea, development and analysis
Jay Bigam — Computer / technical / programming / web hosting

Invaluable assistance has also been given by Dr. Karl Ludvig Reichelt, of the University of Oslo, and Karyn Seroussi, author of Unraveling the Mystery of Autism & PDD.

16. November 2001
Jørgen Klaveness
Høienhaldgt. 4
N-1532 Moss
This email address is being protected from spambots. You need JavaScript enabled to view it.


Several researchers (Reichelt, Shattock, Cade, Knivsberg, Eggers, Friedman, and others) have worked on the possible connections between the incomplete breakdown of proteins (identified by the abnormal presence of opiate peptides found in urine samples), and several kinds of health problems hitherto classified as mental. Among these problems are Autism, Pervasive Development Disorder (PDD) and Asperger’s Syndrome.

An increasing number of families have, on the strength of their hypotheses and the increasing amount of evidence pointing to these connections, have started to use dietary intervention in the treatment of their autistic / PDD / AS children.

While some of these dietary experiments have been extremely success­ful, other families have been less lucky. The survey was designed to collect as much information as possible about these dietary experiments, and to subject the collected data to whatever statistical analysis that can help to throw light on the subject.

Public Interface

The GFCFKids Diet Survey is an integrated part of the website, and connected to the GFCFKids online support group. At present, this group consists of around 2000 families and professionals, all of whom are interested in or involved in dietary experiments of the type mentioned.

The common denominator for these experiments is the elimination of Gluten and/or Casein from the patients’ diets, hence the abbreviation GFCF for the Gluten-Free and Casein-Free diet.

The survey collects its information through two questionnaires, called the Main Survey form and the Infringements Experience form. More information about these forms, as well as links to them, can be found at

Researchers who want to look more closely at the survey’s data are invited to contact us. We would also very much like to get in touch with volunteers that can help out with the analysis of multiple variables.

Development of the Survey

The GFCFKids Diet Survey is currently the largest informal study done of the GFCF diet. The GFCFKids group has grown to more than 2000 members in two years. All of these members are in the process of gathering experience about the diet, and in due time, we hope to get most of them to share that experience through the survey. Until well-funded scientific studies are in place, this could come a long way toward answering some very important questions.


The most basic questions to which we want answers are:

What percentage of respondents get better on the diet, how much improvement can there be, and how fast does this happen?

It's been clear for a long time that while many people get excellent results with the GFCF diet, other patients are less lucky. A great number of patients seem to get very much better, very quickly. In addition to details about the above questions, we also want to know:

Why do some patients get better results than others? What are the similarities and differences between those who do well on the diet, and those who don't?

These are extremely important questions. We can’t expect to answer them fully, with the methods that we are using, but we hope to approach at least some partial answers, or at the very least to create the basis for a deeper and more thorough study of selected groups.


The survey uses the Autism Treatment Evaluation Checklist (ATEC) as its main tool to measure improvement or regression.

The ATEC test sheet is developed by the Autism Research Institute, and is freely accessible on the Web at

The ATEC checklist requires the respondent to answer a series of fairly straightforward questions about the patient’s problems. When this has been done, the system returns a set of numerical values that indicate the amount of problems in each of four separate sectors. The total score will be around zero for most NT (NeuroTypical) people, and it will rise to 180 if you select the worst case answer to every single question.

There is some degree of subjectivity about the scoring, but the test can be a useful tool for measuring improvement or regression, especially when administered by the same scorer. The general reliability of the ATEC has turned out to be quite high (see


The main disadvantage of our method is that the respondents are not chosen randomly from those who have tried the GFCF diet for their children. They are mostly self-selected families who have had reason to believe that their children had a dietary link to their autistic behaviors. They are also those who had sufficient motivation to share their information, which is far more likely to be found in the successful cases than among the non-responders.

However, we have a high number of beginners on the survey, who knew nothing about the child’s response when they entered their first ATEC score. As we continue to collect data, if a sufficient number of these fill out follow-up reports, the selection error will be less of a problem and we will have a somewhat better idea of the percentage of responders in the autistic population.

The second disadvantage of the self-reporting method is that lots of beginners report that they have eliminated every trace of gluten or milk from their children's diets. This is far easier said than done, and without professional guidance, caregivers will often continue to discover hidden sources of forbidden protein in the first six to twelve months. Therefore, the group of respondents that reports perfect eliminations is likely to be suspect.

A third problem exists in the recognition of symptoms following an infringement episode. Unless observers are familiar with the symptoms of dietary infractions, they might not notice some of these symptoms unless they are pointed out.

Despite the imperfections of the Survey, our hope is that these results will help provide parents with the motivation they need to this intervention for their children, and to aid in the design of larger controlled studies that can provide us with more reliable data.

The Main Questionnaire

The main GFCFKids Diet Survey questionnaire has several categories of questions:

  • Information about the patient: age, number of months on the diet, ATEC scores, and blood type. They are also asked to submit their e‑mail addresses for identification purposes. The respondents are also asked to state whether they act as parents or professionals.

  • What dietary eliminations are used (gluten / milk / yeast / soy / corn / eggs / others) and to what degree (perfect / near perfect / partial / not reduced).

  • List nutritional supplements and other interventions, such as the use of ABA (Applied Behaviour Analysis).

All data are submitted on the condition that they shall be treated confidentially, and that they shall only be used for statistical purposes.

The Infringement Questionnaire

For the first four months, diet infringement experience was just one single question in the main questionnaire. However, it became evident early on that this information needed a lot of structure to it, before any analysis was possible. Therefore, a separate questionnaire has been made out on the subject of dietary infringements. The main questions on this are:

  • What kind of dietary infringement (gluten / milk / soy /...),

  • Reason (accident / intentional /...),

  • Amount ingested (milligrams / grams /...),

  • Amount of experience (once, 2‑5 times, 5‑10 times /...),

  • Type of reaction (enlarged pupils / hyperactivity / bed wetting / aggression /...),

  • Degree of reaction (none / slight / strong)

  • Delay before reaction (minutes / hours / days /...)

  • Duration of reaction (hours / days / weeks /...)

  • ATEC scores at worst point of regression

We hope that we will, in time, find patterns in the way that people answer these questions, and that these patterns will prove helpful in the diagnosis and treatment of autistic children, and in the interpretation of experimental dietary intervention.

The Control Group Questionnaire

We also have a third questionnaire, that’s meant to be answered by people who have not yet tried the GFCF diet, but who have nevertheless had some experience with the improvement rates of their children / patients.

Summary: How many get how much better, and how fast?

What rates of improvement can be expected? Improvement rates vary a lot. For the time being, we do not know why some patients undergo total changes of personality in the course of one or two weeks, whereas others have to wait for months for much less spectacular developments. This is an area that calls for serious research .

One hundred and thirty-nine respondents have filled out follow-up reports. We have divided them into six groups, based on the total percentage of change in their ATEC score.



Average age at diet start

Average time spent on diet

Average change in ATEC score


11.5% (16)

3.0 years

18 months

-85 (82 %)


29.5% (42)

3.3 years

13 months

-54 (62 %)


27% (37)

4.7 years

8 months

-28 (38 %)


22.6% (31)

4.4 years

7 months

-12 (16 %)






No result

5% (7)

5.7 years

1 month



4.4% (6)

5.5 years

7 months

+5 (16 %)

Clearly, age at start of diet and length of time on diet are key predictors of success.

Sensational Recoveries

Among the progress reports, there are five that belong in a category by them­selves. They could be called sensational recoveries, because they describe extremely impressive improvement in very short periods of time (two to six weeks after starting the diet). These five children lost an average of 57 ATEC points in an average of 3 weeks.

For the time being, these results should be used as inspiration, and not as examples of what is most likely to happen when one tries the GFCF diet. However, these five reports indicate very clearly that the miracle cases that we have heard about are not just rare, singular occurrences, and are not limited to children under two years of age.

Age At Diet Start

Weeks on Diet

ATEC Before Diet

ATEC After Diet

ATEC Points Lost




























Autism is a severe, lifelong disorder with serious emotional and financial consequences. Its incidence is rapidly increasing, and its etiology is still unclear. Due to the lack of mainstream studies that identify the underlying metabolic issues apparent in some cases of autism, it is up to the caregivers of persons with autism to make decisions about treatment options based on anecdotal reports of improvement or recovery.

Although these are preliminary results from an informal survey, they add to the body of evidence that indicates that dietary intervention can be a valuable treatment option for some people with autism spectrum disorders, and in some cases, may lead to the complete reversal of autistic behaviors.

In addition, it is clear from the results that in most cases, time is a critical factor: the age of the patient at the time that the diet is implemented is a key predictor of success.

To participate in this survey, please visit


The content on this website is not to be taken as medical advice. We have gathered information here so that you can make an informed decision in partnership with your medical practitioner.

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Lisa S. Lewis, Ph.D.

Lisa S. Lewis, Ph.D. Lisa S. Lewis, Ph.D. is the author of Special Diets For Special Kids I & II, the foremost books on gluten and casein-free diets for children with disabilities.

Karyn Seroussi

Karyn Seroussi Karyn Seroussi is the author of Unraveling the Mystery of Autism and PDD, the story of her son's autism recovery through dietary and other biomedical interventions.

Helping since 1995

Together Lewis and Seroussi created the Autism Network for Dietary Intervention (ANDI.) Since 1995, ANDI has been helping and supporting parents using dietary and biomedical interventions for autism spectrum disorders. Last year, Lisa and Karyn again joined forces and put the sum of their knowledge in a new book, The Encyclopedia of Dietary Interventions. They continue to write and speak on the topic of dietary intervention, and to support other parents around the world.