I remember watching an interview with Angela Lindvall recently, which was taped a few years ago, and she was talking about how when she started to fill out a little more, she got less work. She said that the designers still wanted to use her, but that she didn't fit into the sample sizes. She said that it sucked, but that she wasn't ashamed of getting curves, because that was part of growing up.
She was also saying how models fall into 3 categories: The curvy ones, who are still thin to the average person, but look a bit fuller when compared to other models. Then there's the thin girls, who are natuary that skinny and then there's the third one, which is models who make themselves that skinny, because it's unatural to look that way.