Tobey Maguire went on an "intense" diet for his role in 'Brothers'.

The actor plays a marine who is captured during combat and had to shed a huge amount of weight to accurately represent the physical transformation being imprisoned had on his character.

He revealed: "I dropped a bunch of weight. Through shooting and a break, I had five weeks, and I lost about 20 pounds, which is a lot of weight considering where I started out at."

"It was very intense. I just didn't eat a lot and worked out a ton. I got into a real focused mind-set. I knew what was necessary, I knew how long it was going to take, and I just had to do it."

In addition to losing weight, Tobey also visited a military base to prepare for the role and admitted he was surprised by the bond between the troops.

He explained: "I went to Camp Pendleton near Los Angeles and shared time with soldiers and went through some basic training. I have so much respect for them for putting their lives on the line.

"I was also just amazed at the camaraderie, the brotherhood and sisterhood and that sort of unique perspective on the world that they share with each other. It creates a really intense familial bond."