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Kelly Clarkson

HOW SHE DID IT EXERCISE

Lost "around 20 lbs."

NOVEMBER 2009

The noticeably slimmer Duets star's passion for working out was recently reignited. "I have a boyfriend [talent manager Brandon Blackstock] and no one likes to not be toned when you are dating someone," says Clarkson, 30. The 5'3" singer, who runs and does strength training, also recently said, "I don't indulge in that vacation beer and pizza." Still, she added, "I have no desire to be super-skinny."

Chaka Khan

HOW SHE DID IT LIQUID DIET

SEPTEMBER 2010

The 5-ft.-tall musical powerhouse hit her highest weight-210 lbs.-before losing 60 lbs. in the past year. "For two months, I did nothing but drink shakes three times a day," says Khan, 59, who has now added soups and salads to her diet. Despite a knee implant, she also started walking more and does resistance training twice a week at home. "I used to love large portions of peach cobbler, " says Khan. "Now, if I want to be a really bad girl, I'll drink a hot chocolate."

Rich Sommer

HOW HE DID IT COUNTING CALORIES

SEPTEMBER 2009

To shed 30 lbs., the Mad Men actor went back to basics, carefully logging every single thing he ate. "I did the iPhone app Lose It!," says Sommer, 34. "I just typed in everything I ate, and when it said 'Stop eating now,' I did." When he did want to indulge, he upped his exercise by riding his bike. As a result, the 6'1" Sommer got down to 200 lbs.-even with trips to McDonald's! He hastens to add that he never touched a fry. "I'd get the grilled chicken with no mayo," he says.

Gloria Estefan

HOW SHE DID IT PORTION CONTROL

Lost 32 lbs.!

AUGUST 2010

The Grammy winner, 54, felt the need to tone up when her metabolism slowed down. "I cannot give up carbs because they are good for me, so I basically began cutting my portions in half," she says. She started substituting quinoa for pasta and satisfying her dessert cravings by having just a few bites. She also increased her cardio workouts to five time week and practices Pilates. "I am so proud of my abs," says the 115-lb., size 4 singer. "I have a six-pack now."

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