Lifestyle Health Mark Ruffalo Says It Was 'Really Challenging' to Gain 30 Lbs. for' I Know This Much Is True' "When you're force-feeding yourself, some of the romance of food sort of leaves," the actor said By Claudia Harmata Published on January 16, 2020 03:38 PM Share Tweet Pin Email Mark Ruffalo didn’t hold back when it came to transforming into his latest character. At the TV Critics Association Winter Press Tour on Wednesday, the 52-year-old actor revealed he gained 30 lbs. for his role in the upcoming HBO miniseries, I Know This Much Is True. In the show, Ruffalo stars as two very different but identical twin brothers, Dominick and Thomas Birdsey. Theactor filmed all his scenes as Dominick for the first 15 weeks, before taking five weeks off to transform into Thomas. Thomas is schizophrenic and has been on years of medication, and Ruffalo said he gained weight to accurately portray the effect that can have on someone’s body. Mark Ruffalo as Thomas and Dominick in I Know This Much is True. Atsushi Nishijima/HBO Shailene Woodley, Emma Stone & More Celebs Who Gained or Lost Weight for a Film Role — And How They Did It “We didn’t want it to be like I run and throw a wig on and do the same scene in the same day, so we took six weeks off to really separate these two guys,” Ruffalo said. “And Thomas is on medication, mood stabilizers and anti-psychotics. A lot of people put on weight.” “Putting on the weight for Thomas was really challenging,” he added. “I didn’t expect it to be. I thought I was going to have a fun time doing that, but when you’re force-feeding yourself, some of the romance of food sort of leaves.” Studying his character and what Thomas would have been going through in his life, living with his mental illness, also made those five weeks difficult for Ruffalo. “Those 5 weeks were kind of lonely,” he admitted. “[Thomas] hears voices. Imagining that life. A couple weeks by myself going down into the heart of this mental illness and studying it. The difference between them.” Mark Ruffalo Reveals How Dark Waters Costar Anne Hathaway Helped During ‘Crisis of Confidence’ The Emmy Award-winning actor also admitted he was scared to play this character, because he knew how important it was to portray him accurately and spread awareness about an “important issue.” “It means a lot to me to be honest with that, which means going into that world and getting to know it and getting comfortable with it,” he said. “And that’s challenging, and so that aspect of it was challenging…I was really afraid to play him,” Ruffalo added. “I think it’s really an important issue, and I want to tell it as honestly as possible. The responsibility is on me.” I Know This Much Is True is based on a 1998 book of the same title written by Wally Lamb. The six-part series was adapted and directed by Derek Cianfrance, and also stars Melissa Leo, Rosie O’Donnell, Archie Panjabi, Imogen Poots, John Procaccino, Juliette Lewis, and Kathryn Hahn. The miniseries is set to premiere on HBO this April.