Jake tells us it was his choice to shed the weight for his new movie.
In Nightcrawler, Jake Gyllenhaal plays Lou Bloom, a new, but determined reporter who chases shocking crime stories around Los Angeles. Unfortunately, his curiosity and perseverance -- while good for business -- could land him in some hot water.
Gyllenhaal, 33, reportedly lost the weight by subsisting on a strict kale and chewing gum diet. When ET caught up with the actor, he admitted that going gaunt was all his idea.
“I could feel that he needed to be hungry, you know, and I wanted to explore that idea,” Jake told ET.
RELATED: JAKE GYLLENHAAL IS SUPER CREEPY IN NEW NIGHTCRAWLER POSTER!
While 30 pounds – for a guy who generally weighs in around 180 -- might seem a bit excessive, Jake assured us his methods were completely safe.
"It wasn't unhealthy,” he said. “It wasn't dangerous. In addition to changing his diet, he added a heavy dose of exercise. “Over time I started running a lot,” he added, and then compared his character’s aggressive tactics with a wild animal. “Coyotes run a lot, and I just started doing that.”
One thing we know for sure? Jake looks handsome at any weight!
RELATED VIDEO: WATCH JAKE GYLLENHAAL IN THE NIGHTCRAWLER TRAILER!
Watch the video above to hear more from Jake and to catch a sneak peek of Nightcrawler, in theaters Oct. 31!