Jake Gyllenhaal doesn't believe in nightmares.

He told Variety magazine: "I always have nightmares [but] I don't really believe in nightmares. I don't believe the things that scare us are in our dreams.

"I think they are us communicating with ourselves. Even if I'm scared, I think they are helpful sometimes."

Jake - who was forced to lose 30 pounds for his role in the 'Nightcrawler' - has admitted that his character, Lou, sometimes pops into his mind during the night.

Speaking of how he achieved his dramatic weight loss, he said: "I would try to eat as few calories as possible. 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 weight loss added to the character, according to the film's director, Dan Gilroy.

Dan said: "When you watch the film and see the angularity of his face, the hollow cheeks, the way that his eyes become prominent, it's such a haunting look for a night shoot."