How come you eat so much and are so thin?

Can you even imagine the other way round? Can you imagine yourself telling somebody who haven't done anything against you and even may be to a friend "How come you eat so few and are so fat?" If you're neither stupid nor mean of course you won't. Me neither. And it works for the other way round as well.
I'm very glad to notice some changes concerning people who are a bit or a lot overweight. I know there's still very stupid people to make bad jokes about them but on a general way it's becaming "politically incorrect" to tell bad things about big people and as a result less and less people dare make fun of them.
On the other hand, it's perfectly allowed and accepted to tell things against skinny people. Why?Does it hurt less to be called an anorexic, cancer sufferer or AIDS victim (which is an insult to those suffering of these diseases as well, thanks for them) than a fatso? Is it less humiliating to get such a nickname like flat pancake than jelly cake? Is it less embarassing to get in a shop for kids to buy clothes than to a special big sizes shop? I don't think so. So why nobody reacts?
I'm normal now. Well, I don't like use "normal" to speak about physical appearence because what is normal? What criteria? But let say that I can shop in womens shops and now I'm fitting the norms, it is easier for me to denounce this discrimination. For a very long time, I've been so ashamed that I didn't dare reply and defend myself. I was sure that it was me who was wrong, who had problem, who wasn't normal. How could I feel normal: I'm eating and don't gain any weight. That's against the laws of nature and then I deserved all these comments. I don't feel like that anymore. Yes I eat a lot and no, I don't gain as weight as I should in comparison with what I eat and it's not a crime. I know that a lot of people, especially girls are suffering and don't dare to say anything to protest. I think it's unfair and has to stop. And, well I think now I'd know what reply if I hear again such a big stupidity and spitefulness.