Obese children are brutally savaged by other children as well as adults. Adults who creep into obesity in their later years damn well know it.
I think it's a sign of good manners that we don't go around pointing out unpleasant things about other people's bodies that they are constantly aware of. It makes people feel like shit, and it doesn't do anything positive to encourage them to fix the problem (like it's just sooo easy, anyway, Mr. skinny European)
Reminds me of this Onion video:
http://www.theonion.com/video/in-the-know-should-we-be-shami...
Anyway, I agree with a lot of the rest that was said - especially about sales tax and tipping.