Size 8? Size 12?

Today I went to see Made of Honor. While I liked the movie, I was annoyed by one small thing. One of the bridesmaids was the "fat girl" and they played that up for typical laughs, which didn't bother me. What bothered me was that she insisted they order her a size 8 dress to which one of the girls says wouldn't she be more comfortable in a size 12. She said no, a size 8 because she was going to lose weight and fit into it. Again, the conversation is not what annoyed me, it's the sizes they used. There is absolutely no way this girl could ever fit into a size 8 (which she does in the movie) or a size 12 for that matter. She's more like a size 16 who might be able to squeeze into a size 14. It just annoys me that they make the fat girl a size 12 like that's some kind of a huge size. Stupid Hollywood and their stupid standards.

I couldn't save a pic to put on here, but you can see pics of the girl on her IMDb profile here.