#1: Britney Spears
"She has the ideal body," Ashley Greene tells OK! of Brit, 27, who burns up to 550 calories an hour on the Circus stage. In L.A., Brit does two-hour cardio and strength sessions three times a week and relies on Sunfare's, 1,200-calorie-a-day deliveries.
#2: Jennifer Aniston
Jen, 40, trains with yoga instructor Mandy Ingber three times a week. The Smartwater spokeswoman cooks meals from Jewels and Jill Elmore's book, The Family Chef. "She is natural and really confident. I think that's beautiful," says Shawn Johnson.
#3: Megan Fox
"Oh My God. Megan Fox. She's got a hot body," exclaimed Chuck Wicks. Could it be that Megan was just born perfect? Perhaps. The Transformers star, 23, admits to occasional laziness. "I hire a personal trainer," she says. "He'll come to my house and Ill be like, 'Not today! Not today!'"
#4: Halle Berry
"She's stunning — God made her that way," Darius Rucker tells OK! of Halle. The Bond girl, 42, relies on that famous orange bikini as a fitness barometer. "If I can't get into it, I eat less junk," jokes Halle.
#5: Jennifer Lopez
"She has curves and isn't afraid of them," Karolina Kurkova tells OK! of J.Lo, 39, who keeps her trademark asset toned with high-intensity interval workouts led by Gunnar Peterson and low-cal gourmet meals. "I eat meat. I eat carbs. I even eat McDonalds," says the mom of two.
"Cardio, cardio, cardio!" the SOS singer, 21, tells OK!. I prefer the treadmill. When I perform I dance so much it helps me stay in shape."" She's ditched crabs for egg whites, veggies and fish - but sometimes nibbles a little KFC (hot wings are her fave).
#7: Eva Longoria Parker
"It's hard to appear thin on film when you're short; she does!" LeeAnn Womack tells OK!. Eva, 34, trains with Aimet Victoria, doing strength and cardio workouts several times a week. Eva noshes Sunfare meals, such as fresh grilled salmon in ginger-citrus sauce.
#8: Jessica Biel
"She's sexy-strong," Lisa Rinna tells OK!. Jess snacks right, eating whole-grain-heavy cereal bars and crackers from Kashi. She and beau Justin Timberlake also work up a sweat on the golf course.
#9: Kim Kardashian
"I'm gonna go with Kim Kardashian because of her backside!" said Matt Stillwell. Kim, 28, follows a mostly vegan and macrobiotic diet and tones her curves with trainer Gunnar Peterson. "When I'm in town, I work out five times a week!" she tells OK!.
#10: Kate Beckinsale
Kate's secret is private Pilates sessions which can burn 350 calories an hour. Kate admits she isn't scared of sweets like cupcakes: "I'm not aiming to be Gisele."
sorry if some of the pics are old-ish