Stephanie Pratt

Hills star Stephanie Pratt has laid the blame for her battle with bulimia on the "skinny girls" who populate the reality series.

Pratt, younger sister of Spencer, says she started bingeing and purging on a 5,000-calorie-a-day diet in 2007 after being "horrified" by a scene she shared with Lauren Conrad. "I remember saying, 'I can't believe how huge I look walking over to Lauren,'" Pratt tells Us Weekly.

In another instance, Pratt, who wears a size 0 to 2, says co-star Audrina Patridge advised the 23-year-old to wear a shirt over her bikini while filming in Hawaii.

Producers, however, never pressured her to lose weight, Pratt says. "[But] it's embarrassing working with skinny girls."

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