The truth is, regardless of what the science says about weight and health, the moral argument will always stand: fat people exist, they are in the world, and if human history is any example, they will continue to exist — and therefore, they must be afforded the same rights, access, and dignity that other human beings enjoy. Regardless of their health.
Earth doesn’t have the resources for this. Take flight seating, for example. To give fat people, especially very fat people, the same comfort/room/etc as ‘everyone else’ is prohibitively expensive.
In fact some people are too fat to even fit in an ambulance (look it up), yet it’s hard to argue against ‘everyone has the right to basic medical treatment’. We could build bigger ambos. We could fit them all with crane lifts. But could we afford it?
There is always going to be a line, and wherever it is, someone will be there to complain.