I'm not going to comment with in depth research, but the little work I have put into looking into this, it is not based on much fact. Really, the point is finding what works for you and what doesn't. If you try some amount of wheat and you don't tolerate it well, stop eating wheat! If you eat meat and you can't digest it, just don't put more in your mouth.. It doesn't take a team of researchers for you to know what your body can handle and what it can't. If it is truly night and day difference, you will be able to tell without "scientific astrology", as one source put it. Here is an idea. Try new things. If they agree with you and make you feel better, continue to eat them. If after a few times you realize that they are not helping you, or in fact hurting you, stay away from them. There are better ways to figure out your body than reading a book that classifies ALL people into four groups. Does it seem reasonable that every type A person should eat the same foods? While there may be shreds of truth to the idea of your blood having to cope with some food you put into your body, we are all different. Pay attention to your body. It will tell you what to eat. Yours especially, Dayton. It makes very clear what you should and should not eat. It is up to you whether you will listen. :-)
Hope this helps!