When booking your flight, there should be a box where you put in your body weight.

IN this way, they can cancel you and say you need to fly a private jet. Discrimination? I dunno how you can see that when your plane is not design for people with a certain size category. How about if you are bed stricken and you want to fly Delta, can they remove seats so you can lay flat on your bed and being strolled into that airline?