New Year, New You in 2014

Hollywood's Weight-Loss Winners!

Kirstie Alley, Kellie Pickler, Jonah Hill and more share the slim-down secrets that really worked

JORDIN SPARKS

Dropped 3 sizes!
"I was determined," the 21-year-old singer tells PEOPLE about the motivation behind her successful bikini slim-down. After trying and failing with fad diets, the 5 ft., 10 in. former American Idol winner adopted a more realistic long-term approach, taking up Zumba classes and scaling down her portion sizes. "I've always felt cute, but now I feel sexier," she says.