Mark Ruffalo had to force-feed himself to gain weight for TV show

Mark Ruffalo

Mark Ruffalo had to force feed himself in order to gain 30 pounds (13 kilograms) for his new HBO show, I Know This Much Is True.

The actor plays the dual role of twins Dominick and Thomas Birdsey in the upcoming drama series, which is based on the novel of the same name by author Wally Lamb.

It follows the brothers at different stages in their lives as they deal with the problems stemming from Thomas's struggle with paranoid schizophrenia, and Dominick's grief over the death of his child.

Ruffalo was tasked with gaining weight for the role of Thomas to portray the side effects of the "stabilisers and antipsychotics" he has to take in order to control his condition, and the Avengers: Endgame star has now claimed putting on the extra pounds was a lonely existence.

"When you're force-feeding yourself, some of the romance of food leaves," he said during an appearance at an event for the Television Critics' Association. "Those five weeks were kind of lonely, I'd been away from my family and (Thomas) hears voices, and I was imagining 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."

And the Ruffalo felt a lot of pressure when taking on both roles, and confessed he was afraid to try and depict Thomas's mental illness.

"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," the 52-year-old explained.

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