Christian Bale is a case in extremes. From dangerously starving himself to lose weight for his insomniac character in The Machinist to stuffing his mouth in junk food to gain weight in American Hustle, the Batman star has done it all.
Back home, many of our leading men and women are also all for dramatic physical transformation for the sake of artistic authenticity.
Sukanya Verma lists them out.
Kartik Aaryan, Chandu Champion
Until now recognised for playing cheeky parts in romantic comedies, Kartik Aaryan attempts to push the envelope in Kabir Khan's sports drama inspired by India's first Paralympics gold medallist Murlikant Petkar.
To achieve the correct physicality for the role, he went on to shed his body fat from 39 percent to 7 by training rigorously for one-and-a-half years.
The results are for all to see.
Farhan Akhtar, Bhaag Milkha Bhaag
Athlete biopics demand ardent discipline from actors bringing it to life on celluloid.
Farhan Akhtar's commitment in becoming the lean livewire 'Flying Sikh' earned the actor tons of accolades for his transformation into the legendary sprinter Milkha Singh.
Kareena Kapoor, Tashan
Size zero is a milestone in Bebo's career. The actress adopted a strict diet and workout regime to lose tons of weight and slip into a slinky lime green bikini for her con woman act in Tashan.
She's gone back to her foodie Kapoor ways since but the size zero trend continues to attract gym subscriptions.
Aishwarya Rai Bachchan, Dhoom 2
What's with smouldering swindlers and size zeroes?
Ash's scorching avatar in Dhoom 2 highlights how the already svelte actress lost more weight while flaunting her flat abs and tan to jaw-dropping effect.
Aamir Khan, Ghajini, Dangal
Aamir's stunning metamorphosis into the amnesia-ridden beefcake in Ghajini turned out to be the thriller's biggest USP.
Years later, he piled on the kilos to acquire a dad bod and belly as the father of two adult daughters in Dangal.
Shah Rukh Khan, Om Shanti Om
Remember when six-packs became a household sensation as well as life goal?
One look at SRK's super-hot muscular, shirtless outing in Om Shanti Om's Dard-E-Disco where he plays a Bollywood extra reborn as a movie star and everyone wanted to follow suit.
Randeep Hooda, Sarbjit, Veer Savarkar
Randeep unlocks new levels in method acting by turning reed thin to play an unfairly held convict in Sarbjit.
The man goes a step further in losing weight to portray a freedom fighter in Swatantrya Veer Savarkar.
Vidya Balan, The Dirty Picture
Bollywood's body-shaming ways couldn't deter Vidya from putting on weight or showing it off unapologetically to illustrate the raunchy spirit and rambunctious soul of Silk in the Silk Smitha-inspired unofficial biopic.
Bhumi Pednekar, Dum Lagake Haisha
Bhumi locked her reputation as a brave actor to watch out for in her debut as a independent woman married to a grouchy dweeb unhappy about her overweight frame.
The Yash Raj Films employee turned leading lady went on a binging spree to look the part, which was received with critical acclaim.
Parineeti Chopra, Amar Singh Chamkila
Refusing to let all the rumours and remarks about her weight gain affect her, Parineeti's single-minded makeover until she came close to resembling the character of Amarjot -- Amar Singh Chamkila's significant other and singing half in Imtiaz Ali's gripping biopic is all kinds of inspiring.
