The GFCF diet is common enough in the alternative medicine world of autism to
be sometimes called "The Diet". As in, "Is your kid on The Diet?". Some people
(with autism or not) are sensitive to certain foods and, yes, that can have an
effect on their behavior. Because of this, it is probably the first thing an
alternative medical practioner would recommend.
It's worth reading the account of Dr. Jim Laidler. The
page is titled, My Involvement with Autism Quackery. You see, Dr.Laidler was
not only an autism parent, he was working on the inside of the
alternative-medicine world. He was lecturing at conferences and helping to form
policy for these groups. Then, he found out, he was deceiving himself. His
kids were GFCF (and doing a lot of other alternative-medicine therapies).
Here's his account of how it ended:
The final step in my awakening came during a Disneyland vacation. My younger
son was still on a gluten- and casein-free diet, which we both swore had been a
significant factor in his improvement. We had lugged at least 40 pounds of
special food on the plane with us. In an unwatched moment, he snatched a waffle
and ate it. We watched with horror and awaited the dramatic deterioration of his
condition that the “experts” told us would inevitably occur. The results were
astounding—absolutely nothing happened. I began to suspect that I had been very
foolish.
In the following months, we stopped every treatment except speech and
occupational therapy for both boys. They did not deteriorate and, in fact,
continued to improve at the same rate as before—or faster. Our bank balance
improved, and the circles under our eyes started to fade. And quite frankly, I
began to get mad at myself for being so gullible and for misleading other
parents of autistic children.
Yes, even a medical doctor can be fooled that "therapies" are working, even
"The Diet". If you read the internet, you can find that just about any gain an
autistic child can make has been attributed to the GFCF diet. There are horror
stories of how a single particle of gluten or casein can throw a child into
horrible physical and mental regressions. So, people will say, you can't tell
if your child isn't responding or is just getting microscopic "infractions" that
are keeping the child from advancing. So, people will say, you need to be on
the diet for 1 month, 2, 6, I've even read 12 months.
Any progress in that time can be attributed to the diet. Any failures, to
infractions. Alternatively, non-response can be attributed to not doing
enough. There are variations on the theme, but the "tacks in your foot"
argument is often used. It goes something like this, "Your child is limping
because he has tacks in his foot. If you take one out (say, with the diet), and
he's still limping, don't put the tack back in! You have to find the other
tacks."
This is one of the big problems with "The Diet", or much of biomed in
general. Anything that looks like an improvement means that biomed works, and
you need to do more. Anything that doesn't work means that you haven't found
the right mix, and you need to do more.
I've seen no test that the alternative medical community can use to say a
specific person should be on the diet. There's no clear criteria for what
constitutes "succsess". This is something to do with your eyes open for.