'Wheat Belly' has been discussed and reviewed quite thoroughly on here, but one of Dr. Davis' statements that I haven't seen talked about much is what he says about amylopectin-a and it's ability to raise blood sugar quicker.
I do not have his book, but I've been looking for papers about this without much success. Here's one that talks about different properties, but doesn't mention blood sugar.
That there aren't a lot of references about these three different types of amylopectin suggests to me that Dr. Davis' statement may be simply speculative and/or correlated with the GIs of amylopectin-containing foods in general. Then again, I know I've come across articles that say that rice that has more amylopectin than amylose (e.g., sticky rice in sushi) has a higher GI than rice that has less amylopectin (e.g., basmati).
In response to the last post: The first two articles are both opinions, of 1 person, who does not provide any references. That is hardly scientifically convincing. The last article, while a scientific article, compares beans to wheat based on amylopectin:amylose ratio.
In response to the theory in general: There is absolutely no evidence, ever, anywhere, to support this "super-starch"/"amylopectin-a" theory.
At any level of study of a behavior, like eating wheat, you are going to get the results of an average human's reaction, and have to compare them to your own personal experience. So let's get to it! The suggestion here is not to go jump off a cliff, but to try leaving wheat out for awhile, and see what happens.