Continuing in the footsteps of his physician father, naturopath Peter J. D’Adamo explores what he sees as a solid link between blood type and health. According to his theory, your blood type determines your susceptibility to disease, which foods you can tolerate, and what kinds of exercise are beneficial. When people eat the right foods for their blood type, D’Adamo says, excess weight falls off—sometimes even faster than they might like. It’s a matter of internal chemistry, as D’Adamo explains in his book Eat Right for Your Type (G.P. Putnam’s Sons, 1996). Companion books include Allergies: Fight Them With the Blood Type Diet and Fatigue: Fight It With the Blood Type Diet (both, G.P. Putnam’s Sons, 2005).