1 of 10
Lost 100 lbs.!
She kick-started her weight loss with a stint on Dancing with the Stars in May. Now, the 5 ft., 7 in. actress is maintaining her svelte new shape by dancing "almost every day" and sticking to an organic diet with her own Organic Liaison plan. "To warm up, I do the cha-cha," says the size 6 star, who, at 60, says she's finally found an exercise "that I actually love that doesn't feel like a hardship or a grind."
2 of 10
Lost 70 lbs.!
After realizing that stress made her pack on the pounds, the State of Georgia star enlisted nutritionist Philip Goglia to devise a diet consisting of six small meals a day. The actress, 26, also stepped up her exercise routine – kickboxing is a fave – to three times a week for an hour. "It feels good to put something on and not have a girdle underneath!" she says.
3 of 10
Lost 40 lbs.!
"I was living like a frat guy," the Moneyball star said of his former diet of beer and burgers. Deciding overnight to change his habits, the 27-year-old actor told Kidd Kraddick in the Morning he "went to a nutritionist and started running instead of emotional eating." Showing off his lean new physique, the 5 ft., 7 in. actor says he even makes time to squeeze in "100 push-ups a day."
4 of 10
Lost 20 lbs.!
The bride-to-be, 43, used her impressive run on this season's DWTS to get back in shape before her wedding. "Now muscles I didn't know I had are defined. It's dramatic," the 5 ft., 4 in. star told PEOPLE after dropping four dress sizes. Currently a size 4, the mom of two is ready to slip into her dream wedding dress.
5 of 10
Lost 25+ lbs.!
"I'm surfing every day," the 42-year-old Scotsman told PEOPLE about his preparation for his upcoming surf movie, Of Men and Mavericks. The 6 ft., 2 in. actor, who weighed in at 197 lbs. for his muscle-bound role in 2006's 300, has also ditched weight-lifting in favor of yoga and cardio and a diet rich in protein and vegetables. "I generally train for a role and give everything to that," he explains.
6 of 10
Lost 50 lbs.!
"I couldn't look in the mirror," Fisher, 55, told the Today show's Ann Curry in August of what prompted her dramatic slim-down with the Jenny diet plan. "The Jenny Craig food's good ... I'm addicted to the cereal," said the 5 ft., 1 in. actress, who stayed on track with the help of one of the plan's consultants. "It's sort of like the 12 step," she joked.
7 of 10
Dropped 40 lbs.!
Blaming his age for his steady weight gain, the country superstar admitted that at 44, "you can't eat as much, and you have to work out twice as much." But the singer quickly got his body back into shape by cutting down on burgers and adding a 5-mile run to his pre-show ritual. "I feel young," he says now.
8 of 10
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.
9 of 10
Lost 20 lbs.!
After indulging in her self-confessed love of deep-fried food and "sympathy eating" with a pregnant pal, the 5 ft., 3 in. country star got back into tip-top shape by cutting out junk food and nixing late-night snacks. But the 25-year-old newlywed still lets herself indulge once in a while. "A little cheese," she confides. "It's a weakness."
10 of 10
Lost 20 lbs.!
The 30 Rock star took just three months to drop the pounds after cutting "refined sugars, desserts and sweets" from his diet. The 6 ft. actor also credits his 27-year-old yoga-instructor girlfriend, Hilaria Thomas, with being a "good influence." She follows the same healthy diet and encourages her 53-year-old beau to keep up regular yoga sessions.