[prmoustache]

If you don't account for leg length, or lack of thereof which affect large people more than seat width, any not morbidly obese adult fit in an Airline seat. You may have a distorted view of what consist an healthy adult. And no people spending a lot of time lifting weight to grow muscles more than the typical crossfit athlete would are not healthy. They lose so much flexibility they can't do many simple thing, let alone scratch their back.

The fact is there are many non healthy adults and the question is what do we do about them. Is flying a fundamental right? Should people with over the top obesity have to pay more to use 2 seats? Should large people have to pay extra or business class tickets to get a decent leg length?