Whether it’s for a new movie, their own well being, or because of social pressure, a lot of your favorite celebrities went through some significant weight changes. Here are 27 celebs who lost a shocking amount of weight in a surprisingly short period of time.

1 celebs lost weight

50 Cent – Although he is best known for rapping, 50 also stars in movies and TV shows from time to time. Back in 2010, he played a cancer patient in the movie Things Fall Apart, and he had to lose almost 60 pounds to correctly portray the character. Only a few months after he finished filming the movie, he was looking buff again.

2 celebs lost weight

Christina Aguilera – At one point in her career, Christina gained a lot of weight and it didn’t take long for media to start bashing her. Feeling the pressure, she started cutting down on alcohol and began eating smaller portions. She lost 49 pounds in a matter of weeks.

3 celebs lost weight

Kelly Osbourne – Kelly had a lot of weight issue when she was younger, but in 2013 she decided to commit to a diet and 30 minutes of cardio per day. It took a few months, but Kelly managed to lose 70 pounds! Another thing she did is eat her fattiest meals (like pizza for example) for breakfast.

4 celebs lost weight

Chris Hemsworth – When it comes to crazy things actors are willing to do for a role, nobody compares to this guy. Hemsworth lost quite a bit of weight and muscles while preparing for the movie In Heart of the Sea. Can you believe the difference?

5 celebs lost weight

Tara Reid – Tara used to be one of the hottest actresses in Hollywood who had a very bright future ahead of her, but unfortunately, she fell under the influence of drugs and alcohol. Reid tried to get her good looks back with a couple of liposuctions and some other procedures, but she failed miserably.

6 celebs lost weight

Star Jones – The View co-host underwent gastric bypass surgery back in 2003, which, in combination with some exercises, helped her lose over 150 pounds really fast. She went from 307 pounds down to 140!

7 celebs lost weight

Sam Smith – When the English singer showed up the red carpet earlier this year, everybody was surprised with his weight loss. Apparently, Sam lost over 40 pounds compared to the previous year and he credits his transformation to running and following the steps from Amelia Freer’s book Eat, Nourish, Grow.

8 celebs lost weight

Mark Hamill – Mark reprised his role of Luke Skywalker in Star Wars: The Force Awakens, and in order to prepare for it he lost 50 pounds. He says he was on the “if it tastes good, don’t eat it” type of diet. Carrie Fisher, his co-star from the three original movies, also lost 35 pounds for the film.

9 celebs lost weight

John Goodman – Although he still looked a bit chubby on the movie, John actually lost more than 100 pounds for his role in 10 Cloverfield Lane. How did he manage to do it? He said he just “stopped eating all the time.”

10 celebs lost weight

Jared Leto – Jared used to be a far bigger man back in 2007, especially since he gained 67 pounds for his role in Chapter 27. It took him a while, but in 2013 he finally regained his usual slim figure and he then actually lost additional 30 pounds for Dallas Buyers Club. Apparently, it wasn’t that hard – he claimed that often he just “didn’t eat.”

11 celebs lost weight

Jennifer Ellison – Jennifer made quite a transformation back in 2014. She wanted to lose weight so she jumped on the 800-calories-per-day Cambridge Diet plan and even asked her husband to snap photos of her in her underwear for motivation. It seems that the plan worked, because she looks absolutely stunning now.

12 celebs lost weight

Boy George – The famous English singer, DJ, and fashion designer went through an incredible transformation after giving up alcohol and drugs. He also got on a carb-free and sugar-free diet and started working out five times a week. All of this helped him lose over 80 pounds!

13 celebs lost weight

Adele – It’s no secret that Adele was a bit on the chubby side, but she recently dropped several dress sizes thanks to a diet that consists of a lot of fruit and veggies, lean protein and complex carbohydrates. Adele also stopped drinking tea entirely. She used to drink about 10 cups a day with two cubes of sugar every time.

14 celebs lost weight

Mo’Nique – Despite that the actress constantly claimed that she loved her body just that way it was, Mo’Nique actually decided to go on a diet in 2009, after being diagnosed with hypertension. She completely stopped eating junk foods, fried foods and red meat, and lost 45 pounds as a result of it.

15 celebs lost weight

Rosie O’Donnell – Rosie shed 64 pounds over the course of two years, after undergoing vertical gastric sleeve surgery. This procedure reduced the size of her stomach by about 15%, causing her to eat less.

16 celebs lost weight

Perez Hilton – Popular celebrity blogger Perez Hilton dropped 60 pounds over the course of three years thanks to regular workout routine and healthy eating. Following his incredible weight loss, he started another blog that focuses on fitness and weight loss. After all, why not cash in on the opportunity?

17 celebs lost weight

Charlize Theron – Charlize gained quite a bit of weight for the 2003 movie Monster. The Academy Awards were just a month after she stopped filming, so she had to lose about 15-20 pounds really fast. Her doctor advised against it, but hey – she had too look good for the red carpet…

18 celebs lost weight

Mila Kunis – The beautiful actress is far from chubby, but for the role of ballerina in Black Swan she had to shed additional 20 pounds. She was on a very rigid diet and trained for four hours a day for a total of seven months! Learning ballet when you’re 26 years old is definitely not an easy task, according to Mila.

19 celebs lost weight

Chris Pratt – Chris made an incredible transformation while preparing for his role in Guardians Of The Galaxy. Not only did he lose 60 pounds, but he gained a lot of muscle. He is now in perfect shape and doesn’t plan on going back to that dad bod anytime soon.

20 celebs lost weight

Zach Galifianakis – It’s hard to believe that this is really him… Zach appeared at the 2015 Screen Actors Guild Awards looking super think and everybody was surprised. On top of that, he shaved off his signature beard. How did he lose so much weight? Pretty simple actually – he gave up booze and started exercising regularly.

21 celebs lost weight

Khloe Kardashian – Khloe is somewhat of a black sheep in the Kardashian family. She was always a bit chubby and never really looked as impressive as her sisters, and the public took note of that. Some people even made fun of her, that is until she became addicted to working out. She’s rocking a totally different body right now and everybody is impressed!

22 celebs lost weight

Melissa McCarthy – The star of Mike & Molly talked about her struggles with weight on several occasions. She even said that she “used to cry about why I wasn’t thinner or prettier” in the past. No reason for that anymore, because since last summer, Melissa looks much healthier and more beautiful with each passing day.

23 celebs lost weight

Kevin Smith – The legendary director and actor showed the entire world that exercising regularly pays off when he shared the photo above via Twitter last summer. Kevin said that he managed to shed 85 pounds in a matter of months. Good job, Kevin!

24 celebs lost weight

Jonah Hill – Jonah used to be quite chubby early on in his career, but back in 2012 he decided to lose a lot of weight for his role in The Wolf of Wall Street. He has regained some of the weight since then, but he’s definitely not that chubby boy from Superbad anymore.

25 celebs lost weight

Oprah Winfrey – Oprah decided to get healthier and drop 60 pounds just in time for her 60th birthday. She still has that signature hourglass figure, but is definitely in much better shape right now.

26 celebs lost weight

Snooki – Although Snooki was never extremely overweight, she was definitely chubby during the Jersey Shore days. Some time after the show ended, Snooki decided to turn her life around, and she lost about 50 pounds in a relatively short period of time.

27 celebs lost weight

Janet Jackson – Back in 2005, Janet weighed almost 180, which is quite a bit, especially considering her height. This is when she decide it was time to change her habits and she successfully lost almost 60 pounds in just four months. The singer occasionally struggles with emotional eating, but despite that she manages to keep her weight under control.