15 Celebrities Who Lost a Ton of Weight

"The Voice" judge stunned audiences in 2013 with her dramatic weight loss.

"I've been through my highs, I've been through my lows. I've been through the gamut of all things in this business. Being too thin, being bigger," Christina Aguilera told Marie Claire magazine.

The British singing sensation was always beautiful. And let's not forget that gorgeous voice. The 27-year-old mother of one has also always been candid and open about her weight. But her dramatic weight loss came about as a bit of an accident.

"I was trying to get some stamina for my tour," Adele told Vogue about her healthier lifestyle. "So I lost a bit of weight. Now I fit into normal, off-the-shelf clothes — which is really a big problem for me!"

We like Adele at any size!

The "Scandal" creator caused quite a stir when she recently dropped 98 pounds in one year!

"I realized that I could either spend my life thinking, 'I wish I could lose weight,' or 'I'm going to,' or 'I'm trying to.' One of those was going to need to happen, but I couldn't be the whiner anymore," Shonda Rhimes, who has three children, told Women's Health. "But I was like, 'This isn't ever going to be any fun, but you're just going to have to do it anyway.'"

She looks great!

The former "Roseanne" star is known for his husky on-screen persona, but that didn't stop John Goodman from finally dropping more than 100 pounds. Goodman chatted with Howard Stern and said, "I decided to stop stuffing food into my mouth every five minutes. Turns out I was just eating all the time. Any time I had my hands open or free, I shoved something in my mouth. It's all crap."

What an amazing transformation!

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The once-zaftig "American Idol" alum is not only an Oscar winner, but Jennifer Hudson also won the battle of the bulge when she lost 80 pounds as the spokeswoman for Weight Watchers. She's even managed to keep it off! Hudson, who wanted to get thin enough to post a bikini selfie, told Yahoo!, "That was a goal of the summer! I was like, 'I want to put on a swimming suit this summer!'"

Good for her!

The 23-year-old British singer, and recent Oscar winner, dropped nearly 50 pounds this year. Sam Smith isn't shy about discussing his relationship with food, telling "Today," "My relationship with food has just completely changed. During the process of this album ["In the Lonely Hour"], I just was getting bigger and bigger and bigger."

Let's hope he keeps the weight off and keeps the music coming.

He stole the show in "The Hangover," but Zach Galifianakis got serious about losing weight after realizing he needed say goodbye to alcohol.

The "Birdman" star told Conan O'Brien, "I stopped drinking and I just kind of put the weight off. … I was having a lot of vodka with sausage—delicious but bad for you." That does sound good!

The talk show host may have lost her season of "Dancing With The Stars," but Ricki Lake won the weight-loss battle by losing at least 20 pounds while training for the show.

"I was on the Derek Hough diet and it works," Lake said. "I lost 20 to 25 pounds, and I went down two sizes."

Good for her!

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Now that Mariah Carey is engaged to one of Australia's wealthiest businessmen, she'll undoubtedly be glad she lost 30 pounds with the help of a Jenny Craig nutritionist. The singer admits she "felt trapped" in her body when she gained more than 70 pounds after the birth of her twins.

We feel ya, Mariah!

She was once known as the chubby Kardashian, but the "Kocktails With Khloé" star just dropped 40 pounds, thanks to her dedication to her strenuous gym workouts. But for Kardashian, getting in shape wasn't just about looking good—it was her own personal therapy after her breakup with basketball star Lamar Odom.

"I definitely think the physical and the mental go hand in hand," Kardashian told People magazine. "I feel so good in the gym that it [affects] the rest of my day. It's a healthy addiction. It's like buying your sanity!"

Although Janet Jackson canceled her tour due to health issues, the world awaits Miss Jackson's return to the stage. In the meantime, Jackson, who's had a very public weight-loss battle, became a Nutrisystem spokeswoman and transformed her bod.

"It's a matter of learning how to keep it off, that maintenance and they have a program for that," Jackson told "Good Morning America."

The "Dancing With the Stars" alum was known for her curves as much as her comedic chops. But after dancing into America's heart, Kirstie Alley lost 100 pounds.

"I feel like I'm back in my element," Alley told Entertainment Tonight. "I honestly didn't even realize what I looked like."

The "Breaking Bad" star attributes her weight loss and weight gain to medication she had to take while filming the TV series.

"I was actually ill while I was filming the show, and it affected my weight," Gunn said. "They gave me cortisone and I puffed up and gained weight. Now I'm better, thank God."

Who knew?

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The comedienne and talk-show host has never been shy about her weight. But in 2013, Rosie O'Donnell went through vertical gastric sleeve surgery. Two years later, O'Donnell is 64 pounds lighter.

"Believe it or not, that surgery changed my life," O'Donnell told People.

We believe it!

The outspoken talk-show host proudly flaunted her curves. But thanks to a strict diet and intense cardio workouts, Wendy Williams lost an amazing 50 pounds.

One of Williams' weight loss tricks? No eating after dark.

Ugh.