Isn't it interesting that the only acknowledgement of medical conditions causing obesity is physical? The mind is more complicated than the body, and depression, anxiety and other mental conditions are often the true cause of eating conditions or weight problems. I would happily sit next to a size 26 lady rather than a judgmental pompous ass. But that's my preference.
It doesn't matter what size the OP is, or what anyone thinks, she is entitled to get on the plane and be treated with respect. Beauty comes in all sizes and true beauty comes from within. For example the response girtbar gave shows true beauty.