Just finished Wheat Belly.
I don't agree with everything in it.
I do think he sometimes overstates his case with inconclusive data.
I do think his style is a bit sloppy.
However, I think there's a lot of truth in most of what he says, and he does try to build a decent case for most of it. He yells loudest about wheat as the worst offender, but thinks we have way too many carbs in the modern Western diet overall. He cites lots and lots of studies, so anyone crying "woo woo" has to face those rather than just his book (though I think in some cases he may stretch the results a tad farther than a good scientist would).
In the end, he recommends: shopping the edges of the grocery store, avoiding processed crap, eating lots of vegetables and meats, not worrying about fats... it's a very Primal/Paleo sort of diet he recommends.
Overall: he comes on a bit stronger for a bit longer than needed or desirable. However, the book reiterates much of what folks here have experienced themselves, and we've all seen what a laundry list of problems can be solved by going Primal, haven't we?
So I think it's a far cry from perfect, but not a bad book by any stretch. It raises real questions about the Western diet and our government's dietary recommendations -- and backs up those questions with scientific studies supporting his claims. For anyone interested in Primal/Paleo or the problems of a wheat-based diet I recommend that you give it a read.
Life is short: Void the warranty.