You know, I'm all for people being happy with themselves. If you like being overweight/obese/big-boned/whatever you want to call yourself, that's absolutely fine, but it can't possibly be healthy. Do you really want to take the risk of saying "maybe I won't be the person who has health problems as a result of my weight"? I wouldn't want to be that person.
Personally, I fit exactly into that lovely "weight bracket" they have for my age and height, but in my opinion, sure I'm not the thinnest, most toned girl you're going to find. I don't see anything wrong with charging people more because they need to take up two seats. I know that some people can't control their weight but that is a far way from being every overweight person you have out there. I was in Greece recently, and even to some extent when I was in England this happened also, and when you eat out there, you don't get half the crap they give you here. The portions are smaller, but they're enough to be filling. The people there don't seem to be hurting from it. I don't see why obesity shouldn't be considered a national issue.
You're all right, how often do you hear people complain about theater seats? I have an aunt who is very overweight and when myself, and another of my aunts took her to see Urinetown, her first complaint was the seat side to which my other aunt said to her, "It isn't their fault you're fat, these are made for average sized people." (I know that sounds horribly harsh and it was, but thats their relationship)
I see no reason why people who are overweight to the extent where it is proving annoying to the people around them, ie the person next to them at the theater or the plane, shouldn't have to pay a bit extra. Do you know how hard it was to sleep on the plane home from Greece because everytime the heavy woman next to me moved the arm rest moved and hit me? I just can't see how people think that's unfair.
And hang on, when did you win the discus?