Stephanie Pratt

California native and younger sister of Hills bad boy Spencer, Stephanie Pratt has remained out of the limelight until this upcoming season. Pratt apparently inherited some of her older brother's party genes and in December of 2007, she admitted to Us that she battled a drug addiction. However, on the third season of The Hills a now sober Stephanie enrolled in the Fashion Institute of Design and Merchandising to find herself studying alongside her brother's ultimate nemesis: Lauren Conrad! In the fourth season of The Hills, Pratt's new friendship with Conrad was put to the limits when Pratt is caught having a candlelit dinner with Conrad's new beau, Doug Reinhart. In June 2009, Pratt opened up to Us about her struggle with bulimia. "The producers never put pressure on us to lose weight," Pratt said. Still, "it's embarrassing working with skinny girls."Click here to stay up-to-date with Us' full coverage of The Hills