From PEOPLE Magazine Click to enlarge
BRITNEY SPEARS
To get her famous abs back, Spears, 27, hit the gym at least 3 days a week for aerobics, jogging and weight training with a trainer.

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JENNIFER LOVE HEWITT
"This was my year to try to feel better," says Hewitt, 29, who started strength training and running up to five times a week.

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MONIQUE COLEMAN
Coleman, 28, lost 15 lbs. on Dancing with the Stars—and now does "spinning, running, hiking—anything fun!"

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KELLY OSBOURNE
Down 40 lbs. since moving from L.A. to London in 2006, Osbourne, 24, says it's because "here, portions aren't so big."

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KRISTY SWANSON
She lost 28 lbs. on Medifast, then started jogging. "My butt and thighs look great!" says the 39-year-old.

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SETH ROGEN
The 26-year-old actor has been working out with trainer Harley Pasternak to prepare for his superhero role in The Green Hornet.

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MARIE OSMOND
By going on Nutri--System, Osmond, 49, lost 40 lbs. "I was a size 14 and I cut it down to a size 4!" she boasted.

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QUEEN LATIFAH
Latifah, 38, lost more than 5 percent of her body weight with Jenny Craig and daily elliptical workouts.

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HORATIO SANZ
The former SNL star, 39, lost around 100 lbs. by cutting back on booze and "eating better," he has said.

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"I do eat junk food, but I eat lots of good stuff as well. There is a way. It's just about taking the time to figure out what you like."

"I had been putting on 5 lbs. a year—it's so easy to do! So I decided to only buy healthy food: salads, fruit and veggies."