Regarding avocadoes, for blood type O, it's the California avocadoes we can't have. The ones from Florida are allowed. (At least according to another author who advocates the BTD.)

There's one part about the diet I don't understand - the secretor & non-secretor, whatever that is. I haven't gotten that deep into it. Apparently, the no-no lists in D'Adamo's book cover both, but if you are a non-secretor (or is it the other way around) some items might not be a problem.