Diane, I'm glad someone finally brought that up! I try and go by that and definitely, definitely feel the difference. I am an O. My husband is an A. One of my girls is an O and one is an A so I guess that blows that theory : ) It makes life difficult in a sense. And its funny. I was always the one who wanted to eat all whole wheat, vegetarian, etc. My husband was a meat man.... Once when we were dating eons ago I made him dinner. I made spaghetti sauce and served it with spaghetti squash instead of noodles. (Actually that is a good idea for us, though!) He had never even seen spaghetti squash before : ) But for desert I made a whole wheat honey cake....Wow. He has never let me live that down LOL : )

Anyway - its hard to adjust to all the things we cannot have, but its actually very consistent with what is healthiest overall anyway. The difference is that A's need soy more. We eat a lot of chicken. My mom is actually a B and my dad an O so I got it from my dad. I had some trouble with Brittney which I now wonder if it didn't have a little to do with our blood type differences. None of us (the two types) are supposed to deal well with wheat or dairy. The A's do well with beans but about the only kind we tolerate is black beans or adzuki but I can't fine them. I think we're also fine with garbonzos. I found rice and spelt pasta which I use to be strict about and then got away from it, but when I did my inflammation issues came back full fury. I have every issue O's can have if you don't eat right. Inflammation, thyroid issues, autoimmune. A's have very delicate digestive systems and that definitely plays out with my husband and daughter. I have all the books. I wholeheatedly agree with it. Didn't want to believe in it, but started noticing the symptoms I would get when I ignored it.