Tiffani Thiessen of 'Saved by the Bell' star loses 45 pounds: Who's the sexiest former child star?

Wow, look at Kelly Kapowski! "Saved by the Bell" hottie Tiffani Thiessen -- the object of Zack Morris' affections -- looked better than ever at a Hollywood event on Wednesday night, rocking her curves in a Little Black Dress.

The 38-year-old actress -- who currently appears in the USA Network drama "White Collar" -- married actor Brady Smith in 2005 and gave birth to a daughter in 2010 -- but the blue-eyed belle of Bayside High School hasn't aged a day. In fact, celebrity trainer Kathy Kaehler recently helped her drop 45 pounds, according to SELF magazine.

SODAHEAD SLIDESHOW: See the sexiest former child stars. 

But Thiessen isn't the only child star who grew up to be super sexy. In the 1996 movie "Beautiful Girls," Portman's teenage character predicted, "I'll be hot." She was right. Alyssa Milano is a married 39-year-old with a baby, but she's just as pretty as she was as a tween dream on "Who's the Boss?" And before she was a "Twilight" superstar, Kristen Stewart played Jodie Foster's young daughter in the 2002 movie "Panic Room."

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For the ladies, Joseph Gordon-Levitt -- the kid from "3rd Rock from the Sun" -- is now a handsome, in-demand actor. And remember when Leonardo DiCaprio played a homeless kid on "Growing Pains"? From Tiffani to Alyssa to Emma Watson, let us know: Who's the sexiest former child star?