I tend to agree with ararat. Disclaimer; I have not read the book. It makes sense however, to listen to one's body PROVIDED the body is allowed to talk, and it has ears (tongue in cheek). Toxic body may send erratic requests for more toxins like sugar.
Healthy body will "place requests" for things that it needs.
We are all different. One man's cure will be another's poison. Not everyone can thrive on blood and high fat goat milk like the big and healthy Maasai tribe, famous for perfect, cavity free teeth.
There is no "best" diet. Raw food diet is neither "good", nor practical in cold climates.
Nature provides different foods for different people in different climate zones. IF there is any truth to eating according to the blood type, we also evolved to ingest/digest different foods depending on who our ancestors where (maybe hunters, maybe shepherds).
Last but not least we are not what we eat, but what we absorb. And that differs from person to person, too.
I am new here, and I hope we exchange ideas without judgment? If so, I hope that my two pennies will be accepted