Top 20 Celebrity Transformations

Khloe Kardashian

While she was previously being one of the bigger Kardashians, Khloe has recently gone through an incredible transformation, as she's lost over 40 lbs. Khloe went from a size 12 to size 4!

The results of her tough workouts and strict diet have surely paid off.

Christina Aguilera

Melissa McCarthy

Melissa McCarthy has recently shown a tremendous transformation because she lost over 75 lbs, which she said she was able to do it due to a high-protein, low carbohydrate diet, regular exercise and a "super-boring life" that includes a 7:30 pm bedtime.

Whatever her secret is, she should keep it up because she looks fantastic.

Jessica Simpson

Rebel Wilson

Although Rebel Wilson doesn't have the typical figure of most actresses in Hollywood, she admits at first she used her weight to help boost her career. She's comfortable being who she is and considers her size to be an advantage for her career.

In April 2016 she began a dramatic weight loss transformation, and over an 8-month period, she's lost nearly 30 lbs. She looks great with a slimmer figure and is sure to continue to make people laught on the silver screen.

Janet Jackson

Jared Leto

One of the most well-known method actors in Hollywood, Leto is known for his devotion to his film roles. So much so, he remains completely in character for the length of shooting his films, even at the expense of his health.

In fact, for his role as Rayon in the film 'Dallas Buyers Club', Leto reportedly lost over 30 lbs, shaved his eyebrows and waxed his entire body. He worked on perfecting the character's voice for weeks and refused to break character duringthe entire film process.

Mariah Carey

Christian Bale

Christian Bale is one of the best-known actors when it comes to body transformations. He has bulked up for roles in films such as The Dark Knight and American Psycho and has put on some major weight for his role in American Hustle.

But probably most notably, his craziest weight transformation came when he played the role of Trevor Reznik in The Machinist when he lost so much weight in such a short amount of time, it caused permanent damage to his body.

Kirstie Alley

Jodie Sweetin

Despite a difficult struggle with both alcohol and drug addiction, the 'Full House' star has overcome some incredible obstacles in her life.

She is now a mother to her daughter Beatrix and looks amazing as the reprised character Stephanie Tanner in the Netflix series 'Fuller House'.

Natalie Portman

Hilary Duff

After she gave birth to her baby in 2012, Duff was criticized in the media for her weight. She was accused of not being able to get back down to her weight before the pregnancy. Duff didn't take the ridicule too lightly. and hit the gym to prove that she can get her body back. Although people now criticize the media for ridiculing Duff for her weight, Duff has the last laugh because she looks great now.

“I was learning how to be a new mom, and I needed to go get my hair done. Then they’re like, ‘Hilary Debuts Her Post-Baby Body!’ I was like, I’m not debuting right now. I’m just going on an errand run! There is way too much pressure on women these days. It took me a whole 10 months to build a baby,” Duff told reporters.

Chris Pratt

Kelly Clarkson

Kelly Clarkson is another celebrity who we've seen throughout the years whose weight has gone up and down. But regardless of the critics out there, Clarkson has maintained a weight which she is happy with at the moment.

When asked about her workout routine, Clarkson said, "sometimes I'm more fit and I get into kickboxing and hardcore, and then sometimes I don't and go, 'Nope, I'd rather have wine!'"

Kim Kardashian

Ryan Reynolds

Ryan Reynolds may be the stereotypical nice guy in Hollywood, but his muscular performance in Blade Trinity was due to many hours spent in the gym. Back in the early 2000's, Reynold was cast playing small parts in cheap comedies, even donning a fat suit for his performance in Just Friends.

But in 2004, Reynolds got his big action movie break starring in the third installment of the Blade movies, playing the Hannibal King. After the film, Reynolds kept his body in shape, a decision the proved to be right when he starred in the film X-Men Origins: Wolverine and eventually Deadpool.

J.K. Simmons

J.K. Simmons is no stranger when it comes to weight changes.

He even admits to being overweight in his younger days. “After the second and final time that I got hugely fat in my life and when I lost that weight six or seven years ago, I pretty much decided that I was going to stay in decent shape for the rest of my life,” Simmons said.

Kelly Osbourne