As she walked the red carpet at the Writer’s Guild Awards last Saturday, Mila Kunis drew stares — but for all the wrong reasons. The That ’70s Show star looked extremely gaunt in a sleek black gown that hung on her teeny-tiny frame. Her arms were pin-thin and bones protruded out of the cutouts of her LBD.

At 5'3", Mila appears to be about 100 pounds, which is a dramatic drop from her estimated weight of 108 pounds last August at the Extract premiere (see pic on next page), where her patterned Matthew Williamson gown complemented a petite hourglass shape. “She is a small woman and needs to be careful to maintain her weight at a certain level and not become too thin, putting her health at risk,” Marcel Bellucci, a personal trainer at Synergy Fitness SoHo who does not work with the actress, tells BettyConfidential.

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Although many of Hollywood’s skinny starlets attribute losing pounds to stress, Mila’s weight loss may be the result of her recent intense ballet training for her upcoming movie, Black Swan. “It’s the most physically strenuous thing I’ve ever done in my whole life,” she said last month. “I was aware of ballet. I’ve seen ballet. But I didn’t realize what it was. I didn’t realize what you had to put your body through in order to look like a ballerina, walk like a ballerina. You can’t fake ballet.”