Hm. I've steered away from this thread so far, but I've now had a socially acceptable amount to drink and want to stick my oar in.
There are plenty of things that I, personally, think should be socially unacceptable. People who park directly outside the shop across the road from me (when there is a perfectly serviceable carpark to the side) and are making navigating out of my driveway marginally more difficult for me, for example. Or people on trains who sit on the aisle seat, knowing that most people are too timid to ask if the window seat is free, thus gaining some extra space for themselves. Or people who don't take care of themselves, smoke, drink too much, don't work out, and die an early death or put undue strain on the health system.
But the problem is, that's exactly where I get unstuck. I'm relatively healthy - I exercise frequently, and not just cycling. I don't smoke, and I eat healthily. But I do drink. A lot compared to the government intake limits. I'm a happy drunk, not a grumpy or violent one, and I don't drink or drive (or drink and cycle) and so my drinking is socially acceptable at least as far as I can tell.
So I find it difficult to outwardly blame people for being fat, or even in the most liberal of terms find it socially unacceptable. Of course, hypocritically, on some level I do, inwardly. The guy on the plane who elbows into my chair will get a swift bollocking, or at the very least a dirty look (or at the very very least a grumbling about when I get home).
I think that there are shades of grey at work here. The guy who enjoys the odd fag isn't anything to get worked up about if he does it with consideration... the guy who lights up in your car without asking is. The guy who enjoys his food is fine, as long as he otherwise keeps himself in check and doesn't invade other peoples space unduly.