Stars live under a microscope in the spotlight and are constantly criticized for their weight, so it's no wonder that some of them decide to shave a few pounds off -- be it for health benefits, in preparation for swimsuit season or any other reason.
Here's a look at 7 shocking celebrity weight loss transformations:
Rebel Wilson, star of "Pitch Perfect," is beginning to look fit perfect these days.
After declaring 2020 her "year of health," the 39-year-old actress began a health and diet regimen that's provided great results.
Wilson shared a photo of herself at the beginning of the year on the beach, just as she was beginning her weight loss journey.
Wilson said she's "deliberately hydrating" and "trying to avoid the sugar and junk food."
A few weeks later, Wilson's trainer shared a photo of the actress in all black athleticwear, as well as a video of her training with CrossFit ropes.
Wilson's trainer, Jono Castano, revealed that she's been working out seven days a week, and it's definitely showing.
Jillian Michaels is best known for whipping people into shape on "The Biggest Loser," but she first had to whip herself into shape.
The fitness guru recently took to Instagram to share a throwback photo, revealing her former weight.
"Here's me at 5'0 tall and 175 lbs," she wrote in the caption. "If I can do it - anyone can. Share your story..."
Of course, the 45-year-old trainer has slimmed down over the years, and is now an advocate for health and wellness.
Jonah Hill was always known as the chubby, funny guy, but in recent years, he's proven that's not always the case -- on screen and off.
Hill started dropping weight between 2015 and 2016 and has continued to trim down since.
The 36-year-old actor is almost unrecognizable compared to his former self.
Hill revealed on "The Tonight Show" in 2016 that he turned to "21 Jump Street" costar Channing Tatum for fitness tips, who simply recommended he eat healthier.
A source told People that Adele's weight loss was inspired by her desire to be "the healthiest mom possible."
In recent weeks, Adele, 31, was spotted on vacation with fellow Brits James Corden and Harry Styles, where some photos were snapped of her soaking up some sun on the beach, looking drastically different.
Looks like the Grammy winner is saying "hello" to a whole new lifestyle.
Christina Aguilera, 39, burst onto the music scene when she was around 20 years old, and since then she's received a great deal of criticism for her weight.
Her weight has fluctuated over the years, rising and falling after the 2008 birth of her son Max.
However, in 2013, Christina Aguilera turned heads at the American Music Awards for her dramatic weight loss.
When asked about her weight loss secret, Xtina told E! News “Laughter, happiness, breathing and I did some yoga.”
Sounds easy enough.
Ethan Suplee is feeling proud these days.
The 43-year-old actor dropped jaws recently after revealing his impressive weight loss.
You may remember Suplee as Louie in "Remember the Titans," but you probably wouldn't recognize him today.
The actor took to Instagram to show off his weight loss.
"This may be my favorite moment of the year in the gym, because it's empty," he captioned the photo. "2020 goal: all the abs. What are yours?"
Honestly, it's a bit hard to believe he even needs to set fitness goals anymore.
Khloe Kardashian is another star who has grown up in the spotlight, but being in a family full of models meant that her weight drew extra criticism.
Kardashian began to work out to cope with the beginning of her lengthy divorce from Lamar Odom.
It wasn't long before the reality star began noticing a difference and pushed on, making a surprising transformation.