Jennie Garth's slimming down secret is not what you might think. "I eat a lot now," the Dancing with the Stars contestant tells Us Weekly. "I love a late-night Dorito."The 35-year-old mom of three (Luca, 10, Lola, 4, and Fiona, 1) has found the alternative to dieting: "Rehearsing for six hours." Garth tells Us, "When I decided to do [Dancing with the Stars], I did pilates three days a week and cardio twice. I hated it, but it helped. Once I started dancing, things changed faster than when I was just working out." Garth says she's dropped 10 pounds since starting on the show, "but it's more about the inches and toning. My jeans were a 29 when I started, and I'm wearing a 27 now," she explains. "It's great to be able to go to the back of my closet and get the clothes I wore [prebaby]." Actor husband Peter Facinelli, 33, is enjoying the benefits of Garth's dancing as well. "He said, 'It's like I got a new car!'" she tells Us. "He can't keep his hands off me. To the point that it's like, enough!" Uh-oh. Garth may be dancing her way to the couple's fourth baby! For more on Garth's transformation, how her DWTS schedule affects her family life, and what her fellow 90210 alums think about the show, grab the new issue of Us Weekly, on newsstands now.