Skip To Main Content

Every product is carefully selected by our editors and experts. If you buy from a link, we may earn a commission. Learn more. For more information on how we test products, click here.

Celebrity body transformations

21 Most Insane Actor Fitness Transformations in History

Actor body transformations are often a story unto themselves, to the point that they occasionally overshadow the actual film or TV show for which they were undertaken. Don’t take that to mean they’re unnecessary, however, as they usually drive home a signature performance and make the story work. Indeed, some films simply wouldn’t be the same without them.

You’ll also like:
Arnold Schwarzenegger’s Diet and Workout Plan
Sylvester Stallone’s Dangerous ‘Rocky’ Diet & Workout Plan
Jake Gyllenhaal Diet & Workout Routine

No matter what the context, celebrity body transformations (meaning actor weight loss and gain alike) offer a fascinating study in extremes. Expanding upon acting’s physical dimensions, they also go to show that there’s so much more to the craft than merely landing one’s lines. It reminds us that behind the glitz and glamour is a whole lot of passion, dedication, and hard work. Talent helps, too.

We’re focusing hard on the transformation that completely altered a celebrities appearance, so you won’t find any super ripped celebrities who managed to get even more ripped (sorry Hugh Jackman). From excessive weight gain to miraculous fitness transformations, we’re bringing you the most iconic examples of this particular trend. Some performances leap to mind while others may seem less obvious. They all remain unified by a certain breed of underlying insanity. But hey, that’s Hollywood. Without further delay, here are the most insane actor body transformations in history. Don’t try this at home!

1. Matthew McConaughey – Dallas Buyers Club

One of the most famous actor body transformations comes to us from Matthew McConaughey, who shed over 40 lbs when preparing for the role of AIDS victim Ron Woodroof. Four months before shooting began, McConaughey consulted with a nutritionist and proceeded “in as healthy a way as I found possible” (to quote him directly), eating “programmed meals” and dropping 3.5 lbs per week. The actor’s weight loss and subsequent performance enraptured critics and audiences alike, earning him a slew of major awards while basically rebooting his career.

Year of release: 2013
Type of transformation: weight loss
Weight loss: 40lbs (18kg)
Role: Ron Woodroof

2. Christian Bale – The Machinist

Speaking of insane actor weight loss, Christian Bale went down to skin-and-bones for this 2004 thriller. He plays insomniac Trevor Reznik, a machinist whose mental deterioration is mirrored by his physical one. Bale reportedly ate one can of tuna fish and one apple per day over the course of four months, dropping from 173 lbs to 110 lbs. He drank only coffee and water and paired his low-calorie intake with some intense cardio and resistance workouts.

Year of release: 2004
Type of transformation: weight loss
Weight loss: 63bs (28kg)
Role: Trevor Reznik

3. Robert De Niro – Raging Bull

De Niro set an early benchmark in celebrity body transformations when playing boxer Jake LaMotta in Scorsese’s timeless biopic. After cutting a relatively muscular figure throughout most of the film, LaMotta balloons in size during the final act. To achieve this feat, production halted for weeks so that De Niro could go to Italy and eat copious amounts of pasta. He came back with 60 extra pounds added to his waistline, breaking a record (at the time) for actor weight gain. The rest is movie history.

Year of release: 1980
Type of transformation: weight gain
Weight gain: 60lbs (27kg)
Role: Jake LaMotta

4. Chris Hemsworth – Thor

As hard as it may be to imagine, Chris Hemsworth was once kind of a scrawny dude. That all changed when he landed the role of Thor, hammer-wielding fixture of the MCU. In preparation for the first film, Hemsworth hired former Navy SEAL Duffy Gaver as a personal trainer. According to Gaver, the actor bulked and shredded by way of “red meat, heavyweights, and some protein powder.” Hemsworth has been a pillar of physical prowess ever since.

Year of release: 2011
Type of transformation: weight and muscle gain
Role: Thor

5. Christian Bale – Vice

Few if any actors are willing to put their body through the wringer like Christian Bale. This time around, the actor gained about 40 lbs to play Dick Cheney, VP to former President George W. Bush. The performance earned him all kinds of critical accolades along with an Oscar nomination.

Year of release: 2018
Type of transformation: weight gain
Weight gain: 40lbs (18kg)
Role: Dick Cheney

6. Christian Bale – American Psycho

We told you that Bale was the king of actor body transformations! When prepping for the role of serial killer Patrick Bateman, the actor took on a fitness program ripped straight out of his character’s own playbook. Consisting of both cardio and strength training, his workouts ran for up to three hours at a time and delivered serious results. It sounds like the perfect addition to our celebrity diet and workout series!

Year of release: 2000
Type of transformation: weight loss/muscle gain
Role: Patrick Bateman

Fat mac

7. Rob McElhenney – It’s Always Sunny in Philadelphia

One might ask: why did TV star Rob McElhenney gain over 50 pounds again? Because it was funny, naturally. It was also the actor’s way of skewering other fitness transformations while undermining his character’s own vanity. Just as impressive was the fact that he returned a few seasons later looking totally jacked.

Year of release: 2011 (Fat Mac) and 2018 (Jacked Mac)
Type of transformation: weight gain followed by weight loss and muscle gain
Weight gain: 50lbs (22kg)
Weight loss
: 45lbs (20kg)
Role: Mac

8. Chris Pratt – Guardians of the Galaxy

Best known at the time as Andy Dwyer in “Parks and Rec,” Chris Pratt reinvented his body and career alike in this surprise smash. With help from personal trainer Duffy Gaver and nutritionist Phil Goglia, the actor dropped 60 lbs in approximately six months, simultaneously bolstering his muscular profile.

Year of release: 2014
Type of transformation: weight loss/muscle gain
Weight loss: 60lbs (27kg)
Role: Peter Quill aka Star-Lord

9. Jake Gyllenhaal – Southpaw

People couldn’t believe their eyes when they saw early stills from this sports drama, in which a shredded Jake Gyllenhaal plays boxer Billy Hope. When training for the role, Gyllenhaal practised a truly dedicated fitness routine, working out for as much as six hours per day for six months straight. The result was 15 lbs of extra muscle and one of the most impressive actor body transformations in recent memory.

Year of release: 2015
Type of transformation: muscle gain
Role: Billy Hope

10. Jared Leto – Chapter 27

Jared Leto is another actor who’s willing to go to physical extremes in his pursuit of a better performance. He shed 40 lbs for his role in “Dallas Buyer’s Club” and later gained a whopping 67 lbs for this sluggish drama, in which he plays real-life murderer Mark David Chapman.

Year of release: 2007
Type of transformation: weight gain
Weight gain: 67lbs (30kg)
Role: Mark David Chapman

11. 50 Cent – All Things Fall Apart

No stranger to film and TV, rapper 50 Cent went from 214 lbs down to 160 lbs for this sombre sports drama. He portrays college football player Deon, who pursues his athletic dreams in spite of a cancer diagnosis. Mr. Cent (real name Curtis Jackson) went on a liquid diet and performed extreme treadmill workouts to drop nearly 60 lbs in about nine weeks.

Year of release: 2011
Type of transformation: weight loss
Weight loss: 60lbs (27kg)
Role: Deon

12. Zac Efron – Baywatch

The star of “High School Musical” was all grown up by the time he appeared in this poorly received comedy, a tongue-in-cheek update to the campy TV series. Personal trainer Patrick Murphy honed Efron’s already fit physique through a strict diet program and series of high-intensity workouts. As crappy as the film may be, have you seen those abs?!

Year of release: 2017
Type of transformation: muscle gain
Role: Matt Brody

13. Chris Evans – Captain America

Let’s make one thing clear off the bat: Chris Evans did not scale himself down to size to play “skinny” Steve Rogers in the first Captain America film—that was a mix of body doubles and CGI. The actor did, however, beef himself up for the role in the original outing and the sequels that followed.

Year of release: 2011
Type of transformation: muscle gain
Role: Steve Rogers aka Captain America

14. Michael Fassbender – Hunger

This historical drama tells the true story of IRA prisoner Bobby Sands, who led a 66-day hunger strike in 1981. Taking the role to heart, Michael Fassbender ate as little as 900 calories a day while performing various exercises. He dropped 42 lbs in the process and reached a reported final weight of just 127 lbs.

Year of release: 2008
Type of transformation: weight loss
Weight loss: 42lbs (19kg)
Role: Bobby Sands

15. Matthew Fox – Alex Cross

When it comes to celebrity body transformations, Matthew Fox ranks up there with the best of them, reportedly shedding a fifth of his body weight for this 2012 thriller. He plays a crazed assassin named Picasso, nemesis to Dr. Alex Cross (played by Tyler Perry). The actor’s weight loss involved a rigorous combination of exercise and diet, hence his character’s thin but muscular physique. Unfortunately, no one really went to see the film.

Year of release: 2012
Type of transformation: weight loss
Role: Picasso

16. Tom Hardy – The Dark Knight Rises

Already an imposing presence, Tom Hardy reportedly added 30 lbs of mass when tackling the role of supervillain Bane. It just goes to show that if you’re going to break Batman’s back, you best make it look believable!

Year of release: 2012
Type of transformation: muscle gain
Weight gain: 30lbs (13kg)
Role: Bane

Jk simmons

17. J.K. Simmons – Justice League

Actor J.K. Simmons isn’t the first name that leaps to mind when you think of celebrity body transformations, but he basically went full meathead for the role of Commissioner Gordon. That involved teaming up with ex-marine turned personal trainer Aaron Williamson, who’s worked with everyone from Dwayne Johnson to Jamie Foxx. Together, they whipped Simmons into the best shape of his life.

Year of release: 2017
Type of transformation: muscle gain
Role: Commissioner Gordon

18. Ryan Reynolds – Blade: Trinity

Ryan Reynolds was coming off of films like “Harold & Kumar Go to White Castle” and “Van Wilder” when he co-starred in this vampire action flick. The role prompted serious lifestyle changes and also pushed the actor past his perceived limits. Not only did he pack in 25 pounds of serious muscle, but he also ran the New York City marathon and climbed Machu Pichu (elevation 8,000 feet).

Year of release: 2004
Type of transformation: muscle gain
Weight gain: 25lbs (11kg)
Role: Hannibal King

Kumail nanjiani eternals

19. Kumail Nanjiani – Eternals

Proving once again that MCU instalments are synonymous with actor body transformations, comedy icon Kumail Nanjiani recently sculpted himself into a man of steel. No, not that man of steel, rather an egomaniacal alien named Kingo Sunen. As one might expect, the 41-year-old actor and self-proclaimed comic book fanatic spent serious time at the gym, overcoming a number of hurdles on his way to a dedicated fitness regimen.

Year of release: 2021
Type of transformation: muscle gain
Role: Kingo Sunen

20. Gerard Butler – 300

Baring an angry temperament and washboard abs, Gerard Butler burst onto the mainstream when he starred in this action-packed epic. His brutal workout regime was fit for a Spartan and it involved tons of strength-building exercises, with little to no rest between sets.

Year of release: 2006
Type of transformation: muscle gain
Role: King Leonidas

Ryan gosling the lovely bones

21. Ryan Gosling – The Lovely Bones (Lost Role)

What happens when celebrity transformations go wrong? Ask Ryan Gosling, who took it upon himself to gain 60 lbs when preparing for this adaptation of a best-selling novel. Director Peter Jackson was so dismayed by the actor’s weight gain that he fired Gosling before production began.

Year of release: 2009
Type of transformation: weight gain
Weight gain: 60lbs (27kg)

You’ll also like:
Arnold Schwarzenegger’s Diet and Workout Plan
Sylvester Stallone’s Dangerous ‘Rocky’ Diet & Workout Plan
Jake Gyllenhaal Diet & Workout Routine

General FAQ

How much weight did Christian Bale lose for The Machinist?

Actor Christian Bale reportedly shed as much as 62 lbs when preparing for the role of insomniac Trevor Reznik in this 2004 thriller. He weighed as little as 120 lbs during the shoot.

How much muscle did Chris Evans put on for Captain America?

When training for the role of Steve Rogers aka Captain America, it's been reported that Chris Evans puts on as much as 20 to 30 pounds of extra mass, with most of it being muscle mass.

What does Chris Hemsworth eat in a day?

In a given day, Chris Hemsworth has been known the eat the following foods and supplements: protein shakes, eggs, yoghurt, fruit, chia seeds, nuts, BCAAs, vitamins, minerals, lean proteins such as chicken and fish, sweet potato, salad, and rice crackers with Vegemite.