You know, I think young Irish women and girls are actually heavier than young American women and girls - at least those in the part of the US where I was the past two weeks (I've been told that people are heavier in the mid-western and southern states).
I have no stats on this, merely my own observation, but I think it could be true. It's close anyway, which can't be good for the long term health of Irish women. (And, it's women & girls that seem comparable. I don't think Irish men and boys are nearly as heavy as their American counterparts.)
The fact that the girls and young women may have already achieved parity is not good. Too many Americans are overweight and Irish people are catching up on them so quickly that the 'fat American' jokes no longer make any sense to me (and you still hear them). There are so many overweight young women and girls here that it's shocking.