The genetics and blood condition the reactions of the organism with food, according to recent work of Doctor d'Adamo.
A champion nourished with incompatible food will use his body more quickly, nutritional absorption will be of course lower and the disease risks will be increased.
However, to consume products a priori harmful can sometimes have more advantages than of disadvantages, with each one to judge !

In the broad outlines, here are the differences between the 4 blood types:

• Group O (genetic of hunters/gatherers) : needs for meats, bad tolerance with milky products and cereals
• Group A (genetic of farmers) : good tolerance with cereals, bad tolerance with the meats and milky products
• Group B (genetic of nomade) : good tolerance with milky products and fish, bad tolerance with the meats and cereals
• Group AB (genetic more recent) : good tolerance with cereals and fish, bad tolerance with the meats and milky products.

A food list with their compatiblity is on a page of the Doctor d'Adamo site.