Being fatphobic is discriminating against fat people because of there appearance. I think being fatphobic is just as bad as racism, sexism etc. Just like being racist/sexist you are judging someone solely based on their outwards appearance. You dont know anything about them yet you have so many pre conceived ideas about them as a person. And people who claim that they did it themselves and its unhealthy its really none of your business- you really dont need to worry about random peoples health status as anyone can be suffering from health issues skinny, fat, old or young.

Judging and discriminating against someone based on their skin colour, weight, or genitals is all pretty stupid and similar. And you may say its not comparable because weight is changeable. Well i would say weight can be extremely hard for people to change, if it was easy everyone would be slim. And technically you can change gender (transitioning) and skin color ( skin bleaching, makeup, tan,) it is just hard- much like weightloss for a lot of people.

So if you discriminate against fat people you should ask your self if you would like to be discriminated against based on your gender or skin color?

If you are fatphobic you are just as bad as racists and misogynists or misandrists.