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Milla Jovovich

While pregnant in 2007, Jovovich was known to eat three peanut-butter-and-jelly bagel sandwiches a day, and her weight reached 192 pounds. To slim down post-baby in time for her next film—which included bikini scenes!—the actress recruited celebrity trainer Harley Pasternak to work out with her five days a week. Jovovich also followed Pasternak's 5 Factor Diet, which emphasize three small meals and two snacks a day. In just five months, she lost 62 pounds, and used circuit training to get her toned figure back.

Next: Alessandra Ambrosio