Dave Franco almost ruined his health losing 20 pounds for his new Netflix movie: 'I was full-on depressed'

• Dave Franco lost 20 pounds for his upcoming Netflix movie, "6 Balloons."
• It was the first time he'd ever gotten that dedicated for a role in his career and he said it "scared the hell out of me."
• He ran so much to lose the weight, he injured his knee and had to spend a couple of months in physical therapy after production wrapped.

James Franco is the one in his family who's known for being super dedicated to the arts - whether for taking time out of his career to do film classes at NYU, or directing his latest movie "The Disaster Artist" while staying in character as Tommy Wiseau, the outlandish director and star of what's regarded by many as the worst movie of all time, "The Room."

But his brother Dave is proving he can go pretty deep into his craft as well.

The younger Franco, who stars opposite James in "The Disaster Artist," revealed to Business Insider in a recent interview that he lost 20 pounds to play a heroin addict in his upcoming Netflix movie, "6 Balloons." The dedication led to some major ramifications both physically and emotionally.

"I was full-on depressed," he said. "I remember at one point my wife [actress Alison Brie] saying, 'You're not yourself, you're not fun to be around.' And I was like, 'I'm f---ing starving! What do you want from me?' But on set I also wasn't fun to be around. I wasn't really interacting with anyone. I was in the corner by myself, miserable."

In "6 Balloons" (coming out in 2018), Abbi Jacobson ("Broad City") plays Franco's sister who discovers that his character has relapsed on heroin while taking care of his 2-year-old daughter.

Franco admitted the "6 Balloons" role is the first time he'd ever gone deep into a character in his career. Looking back, he's glad he did it, but he also said it "scared the hell out of me."

"I almost really f---ed up my heath," he went on to say. "I was running all day every day to lose weight and I ended up messing up my knee to the point that when we finished production I had to go to physical therapy for a couple of months."

Franco said he got so obsessed with the transformation, he would look at pictures of how Christian Bale has changed his body for roles over the years as motivation.

"If he can do this 15 times I can do it once," Franco said he would remind himself.

Though it was rewarding to do a role that got Franco out of his comfort zone, when the actor was asked if he would ever do a dramatic transformation like this again for a part he quickly responded: "Not for a long time!"

NOW WATCH: SHAQ: What I learned from the failures of 'Kazaam' and 'Shaq Fu'