How and why can a B+ NOMAD add back chicken when it is supposed to be so bad for Bs.
1) Chicken is still bad for nomads. It is a black dot avoid for Nomads in the GenoType diet. Chicken is not a recommended food for Nomads. In the standard blood type diet (from the Eat Right for Your Type Book) there is one level of avoid. In the GenoType diet there are two levels of avoids. Even if GenoType diet was not different than blood type diet if you split avoid foods into two levels, some avoids would be at the higher level and some would be at the lower level of avoid.
But black dot avoids should not be making up a major component of a person's diet.
2) The Blood type diet was primarily focused on whether foods agglutinate blood. While the GenoType diet considers this factor it also considers many other factors. If you consider different issues in determining the ratings of a food the rating may not match some other system. Agglutination does not trump all other factors in the GenoType diet. Your questioning seems to imply it should. Obviously since Dr. D'Adamo set up the system for the GenoType diet, he thought differently on this issue.
On what causes a particular food to be rated in a specific way in the GenoType diet people can only speculate. The book published lists of foods, not an explanation of the rating of each individual food.
Dr. D'Adamo set up a computer program to weigh all the individual factors for a food to determine's its rating in the GenoType diet. So even Dr. D'Adamo may not know all the factors that caused a food to rate a certain way in the GenoType diet. He could obviously deconstruct what his program did for a particular food and come up with the reasons. He explains the concepts at high level in the GenoType book, he explains more how the factor's he considers affect the biochemical processes in the body in the Generative Medicine textbook.
Chicken has both positive and negative qualities for Nomads.
Negative chicken contains
It contains a Metabolotoxin that interferes with metabolism of ABs and Bs
Frequent Bacterial and viral contamination
Not a major Allergen
Significant amounts of protein
Contains significant amounts of Amino Acids (these are considered individually)
Contain some fatty acids (again program considers specific ones)
Contains some Calcium and other minerals (these are treated individually but I do not do that here)
Contains vitamins (again D'Adamo consider the level of a variety of vitamins)
No problem with glycemic index/load
No significant mold contamination
Since I do not know the internals of the software, I do not know how heavily these or other factors were weighted in determining the ranking of foods.