Well, according to Dr. D., dairy products are an avoid (a no-no) for people with O blood. I grew up in Wisconsin, the dairy state, and cheese and milk were SO part of my diet. But it always gave me a stuffed-up nose at night. I think the whole family was pretty phlegmy most of the time. :-)
As an adult I happened on websites like notmilk.com and nomilk.com. Lots of bad press about cow's milk and its link to many diseases. I don't miss it a bit. There are plenty of other ways to get calcium.
As for dark chocolate, I'm pretty hooked on Lindt's 70% -- sometimes the 85%. Because if we're eating it ALSO for the health benefits :-), we have to find the kind that doesn't contain milk. I don't know why brands like Hersey's haven't come out with the "good" kind yet.