(image via DP/30)

When it comes to body transformations, no one does it like Christian Bale.

The star recently packed on 40 pounds to play former Vice President Dick Cheney in Adam McKay's upcoming Backseat, which wrapped production last week.

Speaking with David Poland of DP/30, the 43-year-old Bale isn't shying away from roles calling for extreme weight fluctuations.

"Not as of yet," Bale says. "I still feel like it's alright. For the first time in my life I went to a nutritionist because I'd started another project that I very much wanted to do but it wasn't feeling good. I reckoned, 'Oh, I'm getting older and things are changing and it's risky.' So for the first time I did that, whereas for The Machinist it was like, 'I'm just going to smoke a lot of cigarettes and drink whiskey. Those guys look pretty skinny.'

"I had a picture of Hank Williams on the front of my script getting released from jail at 29 years old. He looked like he was 60. I'm a big Hank Williams fan and I thought, 'Well, alright, he did a lot of heroin, as well. I'm not going to do that but he smoked and drank a lot. I'm just going to do that.' No beer and wine. Just the liquor. But a nutritionist probably wouldn't recommend that method. This time, for my latest project I said, 'OK, we'll do it the grownup way.'"

While Gary Oldman opted for more of a bodysuit and prosthetics to play Winston Churchill in Joe Wright's Darkest Hour, Bale wanted to create more of a "canvas" for the makeup department to work with.

"I like that," Bale says of the transformations. "It's not why I do it but if it's a real person ... I actually like it because I find it makes it easier. If you're looking in the mirror and you're not seeing yourself it makes it a whole lot easier to play the character."

With the aforementioned Machinist, Bale dropped over 60 pounds to play the lead, a 120-pound machinist whose insomnia has left him completely emaciated. A year later he bulked up to 220 pounds to play the Dark Knight in 2005's Batman Begins. Bale got so big that director Christopher Nolan actually had him slim back down to 190 pounds to look more like a martial artist.

Ben Affleck might be wrapping up his time as Batman for the DC Extended Universe, but don't count on Bale reprising the role.

"I think we did it," Bale says of his tenture. "We did it, right? Chris always said a trilogy would be the max. It does feel like a lifetime ago."

According to him, the superhero role never hurt Bale's chances of getting the parts he wanted. It actually helped improve his image.

"Ignorance is bliss," Bale says. "I never had a concern about that. When I was first cast as Batman I never once went, 'Oh, this is going to define me.' It may well be what most people think of me as, of course. What I'm remembered for. That's fine with me. That's whatever people want to think. That's their truth. But I never thought to myself that I won't actually make other films. That's either pigheadedness, stubbornness or ignorance. I'm not sure which but one of the three. Maybe it worked.

"It afforded me the chance, bizarrely, to *help* get a film made. Prior to that was definitely not the case. I was always a hinderance to it. I was always the reason the film was *not* getting made. The director said, 'I want Christian,' and the finances would drop out immediately."