Mark Ruffalo on Gaining 30 Pounds for HBO series, 'I Know This Much Is True'

Shedding away his Hulk avatar entirely, Mark Ruffalo looked completely different when the trailer of HBO series, I Know This Much Is True was released.

The actor is said to have gained 30 pounds in order to play one of the two twins in the show.

At the show’s Television Critics’ Association press tour panel, Ruffalo said that the character of Thomas has a mental illness which means has has to take “stabilizers and antipsychotics” which cause him to put on weight. Ruffalo shot the scenes where he played the other twin, Dominic, before putting on the pounds over a five-week period of force feeding.

“When you’re force feeding yourself some of the romance of food leaves,” Ruffalo said. “Those five weeks were kind of lonely, I’d been a way from my family and (Thomas) hears voices, and I was  imaging that life and there was a couple weeks where I was just staying by myself, going down into the heart of this mental illness and studying it.”

“I Know This Much Is True” follows the parallel lives of the twin brothers in a story of betrayal, sacrifice, and forgiveness, taking place against the backdrop of 20th century America. The series is based on the book of the same name by Wally Lamb, and Ruffalo said he felt a lot of pressure taking on both roles and the mental illness part of Dominic’s character in particular.

“There’s an element of mental illness in this project and you want to be as honest as you can to that, and it means a lot to me to be honest to that which means going into that world and getting to know it and getting comfortable with it,” Ruffalo said. “I was really afraid to play it, I think it’s a really an important issue and I want to tell it as honestly as possible, the responsibility of playing it was really apparent to me.”

In terms of inspiration for the series, writer and director Derek Cianfrance pointed to the famous dinner scene between Robert De Niro and Al Pacino in Michael Mann’s “Heat.”

“They’re never on screen together….(Mann) was creating flip sides of the coin, you can’t see the head and the tail together,” he said.