In the spirit of a not-necessarily scientific poll:
I 'm A+, and I've lost 41 pounds. My O- spouse
is gaining on me, however- she's lost 35 pounds to date.

As far a the results being skewed because O is the most
common: A is a close second- I'd expect a dead heat.

http://anthro.palomar.edu/blood/tab...ncies_in_US.htm