i was pondering this myself a while back while kicking back on AA's 77w in J. I'm not exactly mr skinny any more, and Y is definitely a squeeze on shorthaul ba and aa, but more just from having to pull in the elbows rather than squeezing in the rear! I have never flown longhaul in Y, but knowing the aa 737 and 757 well in Y im assuming it is the same!!