Obese people (250lb+) shouldn't even be allowed in Economy.

Maybe.

On the other hand, in economy on some planes I just literally don't fit in a forward direction because of femur length and cycling muscles, I don't fit in a sideways direction either because of broad shoulders and arm muscles, and I don't comfortably fit vertically on some planes with fixed-position headrests which push into the middle of my shoulder blades and have me hunched the whole flight.

I'm also not _that_ big. I'm 6'2" and have lived my life moderately actively. That's it. I'm biased, but I believe economy should be designed so that I can fit too.

If you agree with that premise, that'd leave plenty of space for most 250lb people too, and there'd be no reason to exclude them.

Man, I hate being rude because I myself weighed 230lbs once upon a time, I get it. I just dealt with a 200lb+ man who spread his legs past the arm rests. Pissed me off the whole flight because I had to contort my body in my own seat so he wasn't spilling into me.

Sweet, free upgrades!

Edit to be slightly less obtuse: surely you're not implying that a common carrier be allowed to discriminate based on facts about a passenger's body without making reasonable accommodations. Surely you're not implying that obese people not be allowed to fly at all. Surely you're not suggesting that fat people should just remove themselves from society so you don't have to deal with them.

Therefore, obese people should get free upgrades to economy plus or better. Thanks for the idea!