From PEOPLE Magazine Click to enlarge
Jordin Sparks

"My body craves the gym," says the 5'11" singer, 22, who dropped the weight with high-intensity cardio sessions, Zumba classes and attention to diet. "I watch what I eat a little more strictly." The American Idol winner danced off some additional pounds rehearsing for her upcoming movie Sparkle.

Kirstie Alley

Fat Actress no more! In the last year the Dancing with the Stars runner-up, 60, shimmied 100 lbs. off her 5'8" frame. She keeps the weight off with her Organic Liaison program and a five-day-a-week dance routine. "If I want to eat more food one day," she says, "I dance longer."

lost 40 lbs.

BEFORE NOVEMBER 2010

BEFORE MAY 2010

lost 100 lbs.

BEFORE FEBRUARY 2010

lost 40 lbs.

Jonah Hill

Losing weight is "part of maturing in body and in mind," the 5'8" actor, 28, told New York magazine. Opting for salads and hitting the elliptical helped transform Hill, who says, "I want to live a long time."

BEFORE NOVEMBER 2009

lost 50 lbs.

Carrie Fisher

Before becoming a Jenny spokeswoman, the 5'1" actress, 55, got rid of her old clothes. She does strength training and cardio up to five days a week in her home gym and is glad to "spend a wad of money on all new stuff!"

BEFORE SEPTEMBER 2011

lost 20 lbs.

Ricki Lake

"Size-6 jeans are falling off me," marvels the 5'4" actress, 43, who was a size 8 before joining Dancing with the Stars last fall. Her stay-slim routine? Portion control and the ballet-influenced Bar Method.

lost 78 lbs.

BEFORE NOVEMBER 2008

Raven-Symone

The 5'3" actress, 25, used to "wake up superbloated" after big dinners. Then she enlisted nutritionist Phil Goglia and began eating up to six small meals a day. "I don't like to sweat," says Symone, who uses the elliptical machine regularly. "But I like to eat, so I'll exercise."

BEFORE AUGUST 2004

lost 52 lbs.

Jerry Ferrara

"The laziness factor is gone," says the 5'7" Entourage star, 32, who has embraced a diet heavy on salad, chicken and quinoa. Ferrara, who used to struggle to last an entire basketball game, now hits the courts twice a week.

BEFORE JULY 2011

lost 30 lbs.

Mariah Carey

After having twins Monroe and Moroccan in April, the 5'9" pop diva and Jenny spokeswoman shed 30 lbs. She stays slim by swimming and cutting back on favorites like pasta. "Health," says Carey, 42, "is a priority."