Wow. I never knew there were so many shallow people on the forum. I've seen several people genuinely trying to justify bullying against fat people and so far I've only seen people agree with them. I'm going to argue against the main points being shouted out because this has genuinely made me angry.
"It's their own fault they're fat!"
So fucking what? If they want to eat a lot, let them. If they don't want to exercise, don't make them. How they live is their decision, and you have no right to judge them for it. I can relate. I'm not exactly fat, but I'm in a similar situation: I hate doing sports. I find it boring and I don't have the energy to do it, and people criticize me endlessly for it, and like the guy ToastiestZombie moaned about near the start of the thread, I tell them to fuck off, because I don't want to do something I don't like doing just to please them and they can't make me. And need I mention, you especially don't have the right to make people feel shit about themselves for being overweight.
"Being fat is hazardous to their health!"
Again, that's their choice. If they don't care, why do you? There's two ways to live if you aren't interested in active things: Force yourself to keep fit and eat healthily anyway, prolonging your life but arguably wasting it away by spending it doing things you don't want to do, or carry on with your normal lifestyle, which will make you die earlier, possibly give you health problems, but at least you're doing what you enjoy with your life.
"They're just as bad to skinny people as skinny people are to them!"
I want you to do something for me. Imagine a pencil-skinny person, then imagine an obese person. Imagine them both standing on opposite ends of a room full of people. Which is going to draw the most negative light? The fat one. Every single part of society paints them in a negative light; magazines always humiliate celebrities for getting fat, models are skinny, TV programs constantly call out fat people as ugly, etc etc. It's not so bad over here as it is in places like America, but in school, fat people are about as loved as plague, while skinny people attract hordes of sympathizers showering them with comments on how they're beautiful no matter what. And you can blame fat people for taking out their problems on skinny people?
"But fat people are ugly! I don't like seeing them!"
If you have arguments to use that are related to attractiveness, I have nothing to say to you.
I could go on but I have better things to do. And I won't be replying to people that argue against what I've said, so don't bother trying to pick an argument. I can't be bothered. But it all boils down to this: They're a bit larger than most people. They eat more than most people. They maybe don't go outside that much. And this is not your problem whatsoever, and it is none of your business how healthy their lifestyle is. You have no right to tell them how to live their lives, and you have no right to bully them for it. You have no fucking idea what bullying does to people. Putting people through it just because they don't live the same way you do is pathetic.
TL;DR: Yes, they are being discriminated against.