Blood Type Diet

Blood group O is believed by D'Adamo to be the hunter, the earliest human blood group. The diet recommends that this blood group eat a higher protein diet. D'Adamo bases this on the belief that O blood type was the first blood type, originating 30,000 years ago.
Blood group A is called the cultivator by D'Adamo, who believes it to be a more recently evolved blood type, dating back from the dawn of agriculture, 20,000 years ago. The diet recommends that individuals of blood group A eat a diet emphasizing vegetables and free of red meat, a more vegetarian food intake.
Blood group B is, according to D'Adamo, the nomad, associated with a strong immune system and a flexible digestive system. The blood type diet claims that people of blood type B are the only ones who can thrive on dairy products and estimates blood type B arrived 10,000 years ago.
Blood group AB, according to D'Adamo, the enigma, the most recently evolved type, arriving less than 1,000 years ago. In terms of dietary needs, his blood type diet treats this group as an intermediate between blood types A and B.