The 'blood type diet' is a diet suggested by doctor Peter D'Adamo. It was described in his book Eat Right 4 Your Type. D'Adamo's writes that ABO blood type is the most important factor in determining a healthy diet, and he suggests different diets for people with O, A, B, and AB blood types.
D'Adamo's writes that human blood type is key to the body's ability to differentiate self from non-self. According to his theory Lectins in foods react differently with each ABO blood type. In his book, Eat Right 4 Your Type, "Lectins: The Diet Connection", and in following chapters, lectins which interact with the different ABO type antigens are described as incompatible and harmful, therefore the selection of different foods for A, AB, B, and O types is important, because it helps to minimize reactions with these lectins.D'Adamo gives unique dietary recommendations:
Blood group O is the hunter, the earliest human blood group. The diet recommends the people with this blood group to 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 that it is a more recently evolved blood type, dating back from the beginning of agriculture, 20,000 years ago. The diet recommends that individuals of blood group A eat a diet rich in 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.
