Are people who're anti-size zero (unintentionally) racist?

Think about it....a lot of people say that "real women" aren't size zero, yet there are plenty, especially those of Asian descent who are. I guess all the size zero (or smaller!) women in Asia aren't real women then. And that's a lot of people. What do you think? Is it unintentional racism? Racism, period? Or just plain ol' sizism that people refuse to acknowledge because it's apparently ok to make fun of thin (especially short and thin) people (since there are non-Asian women who are just as tiny)?