For some roles, like when I was doing Bent, that was harder and I didn't find that helpful because I was so calorie deprived, my brain wasn't getting food. I would end up not being as focused or as clearheaded as I would have liked to be during the run of the performances. I would lose those quality impulses that you lean on when you're acting because of malnutrition. basically. But I looked skinny.

I had done a little bit one other time. This character [in Jack Reacher] is a psychopath, but I had been hired by Carlton Cuse and Randall Wallace.

Psychopaths don't have that charming skill set. They definitely manipulate, but they do it through focused, unskilled means. They're more obsessive.

I had just come off of doing a play in Los Angeles which actually got me the role. It was called Bent and it was at the Mark Taper Forum. I was playing a homosexual in 1930 to 1934 Berlin who is eventually put into a concentration camp for the second half of the play. I had lost about 38 pounds for that.

I only had a three-week break from the beginning of Bent, so I went from one thing to the next. I got back [from shooting Jack Reacher] and there was a sense of, "Oh my God, what do I do now?" I don't have personal trainers around me all the time, I'm not on a meal plan, which I had been on for almost a year straight. There was a lot of sleeping.

I went into very deep research as to what exactly that meant and how sociopaths function psychologically and within the world.

[Jack Reacher] is the longest I'd ever shot anything - and let's be clear, this is my first studio feature film - so there was a huge learning curve.