When Jake Gyllenhaal began researching his character for the upcoming nocturnal crime drama "Nightcrawler," he decided early on to embrace a gaunt, emaciated appearance. 

"When you watch the film and see the angularity of his face, the hollow cheeks, the way that his eyes become prominent," director Dan Gilroy told Variety, "it’s such a haunting look for a night shoot."

Gyllenhaal, who plays a freelance crime reporter, says he ate very little to drop 30 pounds off of his 180-pound frame; a crash diet reminiscent of the one Matthew McConaughey channeled for "The Dallas Buyers Club."

"I would try to eat as few calories as possible," he says, revealing that at most, he would eat small pieces of meat or kale. "I knew if I was hungry that I was in the right spot. Physically, it showed itself, but chemically and mentally, I think it was even a more fascinating journey. It became a struggle for me."

The 33-year-old adds that he further based his fast-talking, lanky character on a coyote. He even ran the 15 miles from his house to the film set each day. 

"There was a general sense that he was a coyote," he tells Variety. "I just wanted to live that way."

Check out the rest of the interview, which details Gyllenhaal's new physical transformation for the boxing film "Southpaw" here. A trailer for "Nightcrawler," hitting theaters October 31, is below. 

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Jake Gyllenhaal says extreme weight loss for 'Nightcrawler' was a 'fascinating journey'
Actor says his inspiration for the fast-talking, lanky character came directly from the animal kingdom.