That seems to be the case most of the time. You really roll the dice with thicker girls because they can hide some of those belly rolls and cellulite in dark clothes.
I hooked up with this hottie but she was total tomboy the way she dressed, but pretty as hell, played volleyball at my college. She wore loose clothes, like sports. When I got her naked she was fit as a mutherfucker. She was totally smokin. Best bod in the world. She just didn't dress that way.