Our friends at Fitbe.com found eight amazing TV transformations that are incredible, indisputable, and inspiring, to boot.
Jennifer HudsonShe turned heads in 2004 when she competed on "American Idol," and again in 2007 when she won an Academy Award for her part in "Dreamgirls."
Now she's in the spotlight once more - with a noticeably slimmed-down frame-as a spokesperson for Weight Watchers.
While her exact weight is unconfirmed, some reports say she lost up to 80 pounds by tracking what she ate, increasing exercise, and meeting with a diet coach from the program.
Bethenny FrankelShe gained 35 pounds during her pregnancy on "Bethenny Getting Married," and just three weeks after giving birth, she was down to 122 pounds, donning a size-4 swimsuit in "Us Weekly."
In November she made her debut on "Skating with the Stars," with a "sick" body, as judge Johnny Weir put it.
Yoga is Bethenny's fitness mainstay, says Kristin McGee, who trained Bethenny.
Ali VincentShe became the first female winner of "The Biggest Loser" in the show's fifth season after losing 112 pounds - 47.86 percent of her 234-pound frame.
Almost three years later, she's still a slim "125 to 130 pounds," finding balance is key to her continued success. "Sometimes that means I give myself a break if I don't get in the workout I wanted to," she says.
Kelly OsbourneIf you remember her as a pudgy teen on "The Osbournes," you were probably shocked to see her newly svelte body rocking a bikini on the cover of "Shape" magazine in November.
Her transformation started in 2009 on the show "Dancing with the Stars," where she lost 20 pounds. In the following months, she lost another 30, bringing her total weight loss to 50.
Patrick HouseHe went from 400 pounds at the start of season 10 of "The Biggest Loser" to 219 pounds in December, and was named the show's most recent winner.
His $250,000 weight loss isn't the only prize. The formerly unemployed father of two was offered a job at MindStream Academy in South Carolina, where he'll help overweight teens trim down.
His best advice: "Diet is important, but not everything. You have to stay moving."
Carrie UnderwoodWhen she won "American Idol" in 2005, she went from regular 21-year-old to superstar overnight. In the years since, she's gone from cute girl next door to, well, super-hot girl next door, dropping 20 pounds by watching what she eats - she's a vegetarian and saves splurges for special occasions - and working out.
Lil' KimDuring her 2009 stint on "Dancing with the Stars," the 4'11" rapper reportedly lost 20 pounds to reach 105 pounds, thanks to a healthy diet and exercise program.
The rigorous "Dancing" regimen - contestants train about 20 hours a week - didn't hurt either.
Michael VentrellaHe started season nine of "The Biggest Loser" as the show's heaviest contestant ever at 526 pounds. Over the course of 18 weeks on the ranch, he lost 50.19 percent of his body weight - a total of 264 pounds - and won the $250,000 grand prize.
Today, he maintains his 285-pound physique with 2 hours of cardio in the morning and 60 to 90 minutes of strength training at night.