As if there isn't enough pressure on an actor heading into a major role, some are also required to look a certain way for the part. Take Hugh Jackman and his portrayal of Wolverine, the actor was in the gym every single day, for three hours.Physically, transformations aren't easy, but they can also have an impact emotionally as well. That was the case for Heath Ledger during his Joker prep, going into a very dark place in order to thrive in the role, one that is still admired by fans today. RELATED - Tom Hanks Had No Idea That An Injury On The Set Of Cast Away Almost Took His LifeChristian Bale is another actor who tends to push the envelope when it comes to transformations, he even did so recently in Thor: Love and Thunder. However, in the following, we'll take a look at his most drastic change yet, which took place during The Machinist.While prepping for the role, the actor was reduced to 200 calories. Although the process wasn't easy, it had a calming effect on the actor. Let's take a look back at his thoughts on the transformation.

Christian Bale Went On A Crash-Diet For The Machinist, Eating 200-Calories Per Day

We've seen some intense diets prior to films, however, Christian Bale's four-month journey prior to The Machinist is truly something else. On the road to dropping 63-pounds, the actor was basically reduced to no food. Per day, he was eating an apple, a can of tuna for protein, and black coffee, likely in order to maintain some type of function daily.

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Bale admits at the time of his transformations, he wasn't able to look at himself in the mirror. Instead, the actor separated himself from the transformation, and made it seem as though it was a completely different person.

"I see actors who can just be themselves and then switch and give these really incredible performances, and then switch back to being themselves," he said.

"I find I start laughing because I'm too aware that it's still me. So I try to get as distant as possible. Otherwise, I can't do it. It's helpful not to look like yourself. If I look in the mirror and go, 'Ah, that doesn't look like me' - that's helpful."

Although the changing process was a rough one, once Bale reached the weight, it had a calming feel.

Christian Bale Felt Like The Lack Of Eating Was Calming And Made Him Feel Zen

Losing all that weight, caused Bale's energy balance to go way down. In doing so however, his stress was heavily reduced. According to the actor he felt calm and Zen while maintaining the look for the film.

"That's the most Zen-like state I've ever been in my life. Two hours sleep, reading a book for 10 hours straight without stopping ... unbelievable. You couldn't rile me up. No rollercoaster of emotions."

"As soon as you start putting the food back in your stomach, the rollercoaster comes back."

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Keeping things simple was the main reason as to why the actor felt at ease.

"Interestingly, I did find that mentally it was very, very calming being that skinny, because you really didn’t have any energy for expending on unnecessary things, so you just kept it simple," he told MovieWeb. "Life became very simple."

The 2004 film wasn't a box office hit, but it received lots of praise from critics, including a 77% approval rating from Rotten Tomatoes.

Christian Bale Is Done Doing Extreme Transformations For The Sake Of His Health

The Machinist is far from the only film Christian Bale had to transform for. He did the exact opposite almost a decade later in American Hustle, gaining 43-pounds. According to the actor, there were a lot of doughnuts consumed along with cheeseburgers and lots of other foods.

However, those days of major transformations seem to be done. Bale acknowledged that at this stage in his career, it isn't wise to keep doing that to his body.

"I've become a little bit more boring now, because I'm older and I feel like if I keep doing what I've done in the past I'm going to die. So, I'd prefer not to die."

"I can't keep doing it. I really can't. My mortality is staring me in the face.”

Set to turn 49 in January of 2023, this seems to be a wise choice by the actor.