I have read many books on diets, and most of them fade away when people realized that they didn't work for them, and to a lesser degree, they weren't based on sound, scientific studies.
This isn't the case with Dr. Peter D'Adamo's work. As a naturopath, he, and his father before him (also a naturopath), saw the link between the blood type of people, and the diet they followed. For example, grains are more beneficial for Type A's, and these same grains are to be avoided by Type O's.
This diet makes sense to me; indeed, I follow it myself. (I am a blood type A).

Therefore, I am a fervent proponent of this way to eat and will provide a menu based on your blood type, if you are interested. Please look at Dr. D'Adamo's website for more information or call me for further inquires.