Michael Specter has written for the New Yorker what is easily the the best article I've read to date on the gluten-free fad:
He writes
“The fear of gluten has become so pronounced that, a few weeks ago, the television show “South Park” devoted an episode to the issue. South Park became the first entirely gluten-free town in the nation. Federal agents placed anyone suspected of having been “contaminated” in quarantine at a Papa John’s surrounded by razor wire. Citizens were forced to strip their cupboards of offending foods, and an angry mob took a flamethrower to the wheat fields.
“No matter what kind of sickness has taken hold of you, let’s blame gluten,’’ April Peveteaux writes in her highly entertaining book “Gluten Is My Bitch.” ”
and
“Joseph A. Murray, a professor of medicine at the Mayo Clinic and the president of the North American Society for the Study of Celiac Disease, has also studied wheat genetics. He agrees with Kasarda. “The wheat grain is not a lot different than it was fifty years ago,’’ Murray told me. “Chemically, the contents just have not changed much. And there is something more important to note. Wheat consumption is going down, not up. I don’t think this is a problem that can be linked to the genetics of wheat.””
and
“While there are no scientific data to demonstrate that millions of people have become allergic or intolerant to gluten (or to other wheat proteins), there is convincing and repeated evidence that dietary self-diagnoses are almost always wrong, particularly when the diagnosis extends to most of society”
The article does go on to speculate a bit about why some people lose weight when going on "gluten free" diets and why the rate of Celiac disease has risen to about 1% of the population. Well worth reading.