In article , Ken Blake
wrote:

In fact, they do have bigger seats which are an option for all of us.
It's called Business Class or First Class.

as well as premium economy and also the exit rows.

They provide more leg room, but not more width. This discussion was
about fat people, so width is the issue, not leg room.

the difference in width for f/j is not a whole lot, typically only a
couple of inches, but what's worse for larger people is that the arm
rests don't go up.

in economy, the arm rests do go up (other than the exit rows), which is
how someone can take up more than one seat.