Why are there three separate recommendations, one each for those of Caucasian, African and Asian ancestry?
ER4YT & CR4YT both recommend portion amounts based on ancestry. In some cases, foods listed as beneficial/neutral were included in a whole category that is to be avoided by a particular heritage. Hence, these foods are considered an avoid for those people.
The Complete Blood Type Encyclopedia is the essential desk reference for Dr. D'Adamo's work. This is the first book to draw on the thousands of medical studies proving the connection between blood type and disease.