Katryding:
Here is some on blood type O, which is supposedly the most insulin resistant and carbohydrate intolerant type, so called "thrifty" genotype. Dr.B also explains this type in his book.
Type O is the oldest blood type, and people with this type blood have digestive systems that hark back to prehistoric times, when the diet was largely composed of extreme protein sources (mastodon, deer, sturgeon, to give a few far-out examples), insects, roots - in other words, hunter/gatherer food. They tend to hyperacidity, thrive when in mild ketosis (brought about by limited carbohydrates in the diet) and do not handle dairy products well. Dr. D'Adamo gives some fascinating examples of type O patients whose cholesterol levels were unacceptably high and who came to him after all attempts to regulate them through diet and medication had failed: on identifying their blood types, he reintroduced lean red meats into their diet and instead limited carbohydrates, with the result that in one case he mentions, intractable cholesterol levels of 350 went to 187, and stabilized there. I need hardly add he doesn't advocate this approach unless under medical guidance! Their major digestive need is for pacncreatic enzymes.

Here are the link for Dr.Adamo "Eat right 4 your blood type" diet site http://www.dadamo.com/
Good luck,
Dina