Although we sometimes forget it, celebrities are humans just like us and their weight, body size and shape can fluctuate depending on lifestyle, health or personal habits. In some cases, certain celebrities completely transformed their bodies for movies roles so with that in mind we've decided to take a look at those stars who altered their habits to undergo dramatic changes.
Whether through better diet or increased exercise, these stars offer up inspiration for those of us who struggle with keeping the pounds off or putting on some muscle.
1. Chris Pratt
Superstar actor who became part of the Marvel film universe when he took on the role of Starlord in Guardians of The Galaxy but it was as the chubby, playful Andy Dwyer in Parks and Recreation that he first really caught the public's attention.
When deciding to go up for a role in The Hurt Locker, Chris thought he needed to get in shape to land it and when producers of the aforementioned Marvel flick asked if he could do it again, he went one better. Now a fully fledged action star who fronts the reboot of the Jurassic Park franchise Pratt keeps himself fit and healthy.
2. Jonah Hill
Since bursting into public consciousness as the rude, crude teen in Superbad, Jonah Hill has transformed into an Oscar-nominated actor who has worked with the likes of Martin Scorsese
Not only has his career changed, however, but also his look as he cut out alcohol and hired a nutritionist to transform the way he looks. His weight has fluctuated over the years but he is looking good and we hope he's feeling better for it.
3. Jennifer Hudson
She wowed us with her voice on American Idol and then used her successful music career to launch one in films as well. Since her humble beginnings as a talent show contestant, she says she has just learned to control her portion size and doesn't have food in her dressing room.
Not particularly one for working out, she does like to keep active.
4. Kelly Osbourne
Singer and reality tv star Kelly was introduced to our screens via The Osbournes which followed the family's individual and collective struggles.
Now a regular on tv talk shows she has slimmed right down and says she uses the Hoopnotica hula hoop every day and works out regularly.
5. Chaz Bono
The only child of performers Sonny and Cher, Chaz is a rather inspirational character. After coming to terms with his sexuality he transitioned to a man in 2008 having been born a woman called Chastity.
After that, Chaz struggled with his weight and has since lost 85 pounds by changing his diet and eating differently saying, “I pretty much eat vegetables, meat, fruit, nuts . . . My birthday is the one day of the year I’ll do cake.”
6. Nicole 'Snooki' Polizzi
Her wild girl antics on Jersey Shore caught the attention of the nation but since becoming a mother she has toned down her partying ways and started exercising more.
“Even though I want to be healthy for myself and it feels great to be healthy, I mainly want to do it for my kids,” Polizzi said. “I just really want to be a fit mom. I want to be able to keep up with them, run after them.”
7. Christian Bale
Christian Bale has become famed for his radical transformations over the years, with his dedication to the craft of acting seemingly knowing no bounds. We've seen this from Bale time and time again, from the 2004 psychological thriller The Machinist where he resembled a walking corpse to ballooning up to portray Vice President Dick Cheney in Vice. But with death recently staring him in the face, one of Hollywood's most famous method actors has finally had enough.
In an interview with the Sunday Times, Bale said, "I can't keep doing it. I really can't. My mortality is staring me in the face." The British actor also admitted that he questioned his extreme ways when he discovered that Gary Oldman hadn't put on any weight to play Winston Churchill in The Darkest Hour, a role which landed him with the gong for Best Actor at last year's Academy Awards.
"By this time I'm 20lb in," said Bale, who is expected to take home the Leading Actor gong on February 24. "I said, 'Wait - none?' I felt like such a tit, but I thought, 'I'm on this road; I'm going to keep going.'"
8. Christina Aguilera
Christina's weight has varied wildly over the years but she managed to get back down to a slender figure simply by eating right and maintaining a healthy diet.
Some speculated it was due to surgery but she set the record straight in several interviews.
9. Susan Boyle
The Scottish singer who shot to fame after her appearance on a TV talent show in Britain in 2009, lost around 70lbs when she was diagnosed with Type 2 diabetes and realized she had to lose weight for the sake of her health. Saying “I needed to stop eating sweeties and cakes. It’s the bane of my life," the singer put together a plan to get healthier.
The singer, who also suffers from Asperger's syndrome, has always been open about her health problems.
10. Drew Carey
Funnyman and tv personality Drew Carey said of his heavier self that it was down to drinking too much and eating junk food.
Self-help books helped him achieve his weight loss before he took on the reins of The Price is Right.
11. Jessica Simpson
Like most people who have a child, Jessica put on weight during and after her pregnancy but she arrested this development and changed it around with the Five Factor Diet.
This had her eating five small meals six days a week and 25-minute workouts.
12. Seth Rogen
Another star who found success with the Five Factor diet was Seth Rogen.
The comedian and film star focussed on what he was eating more and it worked wonders.
13. Jordin Sparks
Singer extraordinaire, Jordin started eating healthier and working with a personal trainer to help her lose 50 pounds in just 18 months following a hectic touring schedule that gave her little time to workout.
Thankfully, Spark's trainer got her moving fast and she's not a shadow of her former self!
14. Jason Segel
The How I Met Your Mother actor didn't do anything special to lose weight but just stopped eating poorly.
“I’ve just been living healthy, exercising, eating right — no more midnight pizzas.”
The American comedian and actress started a weight loss regime for the sake of her husband and children and has since managed to keep the 80 pounds she lost off.
It just goes to prove that anyone, no matter their weight, can achive their fitness goals if they are 100% committed.
16. Josh Peck
Starting out as a child star on Drake & Josh, Josh's career seemed to be one of the heavy-set funny character but he decided to get a nutritionist and personal trainer to help him out.
This proved to be a great decision and Peck achieved his goal of losing the weight without undergoing costly surgery.
17. Miranda Lambert
The country singer decided to lose weight after her wedding citing body image issues and that she felt much more confident going on stage after losing 45 pounds.
You go, girl!
18. Peter Jackson
The Lord of The Rings director was fed up of being unfit so underwent a fitness regime whilst filming The Adventures of Tintin and lost 44 pounds over that period as photos of the premiere prove.
Not bad, Peter!
19. Tom Arnold
Actor and comedian, Tom Arnold claims his weight loss motivation came from his son as he wanted to see him grow up.
Losing over 100 pounds through diet and exercise, he certainly seems to have turned things around.
20. Janet Jackson
Janet is arguably one of the world's biggest singers but has often struggled with her weight.
After losing weight using the NutriSystem, she is now due to give birth to her first child later this year.
21. Ricky Gervais
English comedian and writer Gervais used to be a slender young man when he tried to attain pop stardom in the 1980s.
Failing that he turned to comedy and has always been in the public sphere as a slightly heavier set man but he decided to get in shape along with his girlfriend and ended up losing 40 pounds.
22. 'Mama' June Shannon
The mother of Honey Boo-Bo, the unlikely child reality star, began a regime in 2013 but by January of 2016 she decided to undergo cosmetic procedures after fainting multiple times from strict dieting. Now claiming to have lost 150lbs, the star is hoping to shed more weight by walking and has said: '[I'm] just walking. Once you get started with the kids you don’t think about,' she said. 'You're walking and you’re like ''I've already walked three miles.'''
Posting her current successful results on Twitter, June is hoping to have more good news to share in the future.
23. Jorge Garcia
Famed for playing Hurley in the hit TV show Lost, Jorge Garcia was always recognizable for his large stature. While Garcia would not lose a lot of weight while on the island, he was noticeably slimmer than before the show started. Garcia would end up dropping 30 pounds before the show’s filming started in an effort to get healthy.
Going Vegan in 2011, Garcia is now a regular on Hawaii 5-0 and, although he appears still to be struggling with his weight, is apparently getting serious about it.
24. Kevin Hart
The A-list comedian and actor was never someone who suffered from weight problems, but his diminutive stature meant he found it hard to beef up for roles, so he focused on core strength training to build a defined six-pack.
Trainer Ron Boss even admitted that his client would partake in forfeits if he didn't complete a task in time. "They might have a goal to hit 1,000 pushups each day. The last person to complete the task will be punished, whether that means they’ll pay for dinner, the next round of gas or paying a $1,000 fine."
25. Jared Leto
Leto has been known to change his body shape for roles before, seriously shedding the stones for Requiem For A Dream where he played an emaciated drug user, but he went the other war for Chapter 27 where he piled on the pounds, even force feeding himself to gain the colossal 67 pounds!
The weight gain was so dramatic that he even developed gout from the incident.
26. Tom Hanks
Tom Hanks is a multi-Oscar winning actor, and part of that comes down to his dedication to transforming his body for a role. He lost 55 pounds for the film Castaway to play a man trapped on a desert island and then piled them on for Captain Phillips.
It was during the press tour of that film that Hanks admitted he had developed Type 2 diabetes through his body transformations and would not be undertaking any more roles that would require such dramatic changes in his body.
27. Russell Crowe
Russell Crowe gained a whopping 63 pounds for his role in Body Of Lies by eating cupcakes and cheeseburgers. Initially unphased by his weight gain it wasn't until his doctor pointed out his cholesterol was dangerously high that he started to worry about it.
Crowe's body is far from what it was in his Oscar-winning turn in Gladiator, but he still looks in good shape.
28. Anne Hathaway
For her turn as the starving street urchin Fantine in the musical Les Miserables, Anne really went to extremes to get the impoverished look right. Going on a strict cleanse and losing 10 pounds for filming she then took another two weeks off and lost an additional 15 pounds.
She admits these levels of dedication to her craft were "a little nuts" as she only ate two squares of dried oatmeal a day but it paid off as she won an Oscar for her portrayal.
29. Khloe Kardashian
This gregarious member of the Kardashian clan has always been one of the most comfortable in her skin, but in recent years she's overhauled her diet. Crediting her fabulous new body to gruelling exercise and a strict diet she wrote on her Instagram page: “If you were to ask me five years ago if I ever saw myself being completely in love with fitness and health, that I would be an inspiration to many others, that I would be the push that others needed to find their way—I would've laughed in your face.
“Me? The chubby one? No way! But now I can't see myself ever stopping!”
30. Sam Smith
The heartbreak crooner has conquered the world with his beautiful falsettos and remains one of the industry's most in-demand stars, but even superstars like Sam Smith struggle with their weight. After being pictured topless on an Australian beach, Smith didn't like what he saw and decided to transform his lifestyle. And it's paid off. Since 2015 he has maintained his 50-pound weight loss.
Speaking to the Today Show, the hitmaker admitted that his past relationship with food was unhealthy. "My relationship with food has just completely changed," he said. "During the process of this album ['In the Lonely Hour'], I just was getting bigger and bigger and bigger."