For me it has really helped determing my secretor status to have any success. ER4YT didn't discuss it, LR4YT introduced it but its charts are confusing.
Unfortunately, there was a good site with charts of all the food-groups by blood-type & secretor-status BUT its been removed.
http://www.truehaus.net/food/ gives the nutritional assay of foods(including herbs/spices) WITH their amino-acid profiles.
By comparing the aminoacids of foods you can find the ones good for you. TOO BAD that site is gone.
Just remember that there is more to blood-type than D'Adamo...in fact many scientists dispute his type-O as being the oldest( if you believe in evolution, by the structure of the blood cells, O is not the oldest)
When a fetus is radiated its blood mutates to type-O.