Matt Bomer Reveals How His Kids Reacted to His Dramatic Weight Loss in The Normal Heart

Actor was "separated" from his family for a month during filming

Matt Bomer transformed himself for HBO's The Normal Heart, losing upwards of 35 pounds to play a closeted New York Times reporter who contracted AIDS in the early '80s. His appearance in the film is haunting, and the 36-year-old actor made sure his three sons knew their dad was healthy in real life.

"We definitely prepared our kids really early on, before I even started losing weight," says Bomer, who married power publicist Simon Halls several years ago. "I spoke with a professional who told me how to relay it to them in language they could really understand, and they were great about it. Maybe it's a luxury of having all boys, who are like 'Yeah! Go!' You know, it's like they were my cheering squad. And I remember, at one point I had lost 25 or 30 pounds and I came home, and it's such a testament to childhood imagination, because they were like, 'Oh, I thought you were going to be skinnier than that.' And I was like, 'Hey, I'm working here!' But they were really great about it, and understanding. I think that our oldest son, who tends to be a caretaker, said at one point, 'When are you going to get to eat pancakes with me again?' But that was about as difficult as it seemed to get for them."

Though it was difficult, losing weight gave Bomer invaluable insight. "When the cameras were rolling, I wasn't having to affect anything; so much of it was already there," he tells Vulture. "I had separated myself from my family, I was living on my own for like a month, and I think that helped me sort of get into Felix's head in a way that I haven't had an opportunity to do with other characters before."

In a separate interview with HIV Plus magazine, he goes into further detail about his movie makeover.

"It was sort of one month of casual weight loss and then two months of really aggressive weight loss, and that's when I left my family, toward the end of the second month, and then just lived on my own in New York and really tried to focus on really solely what Felix was going through," he says of his character. "I obviously consulted someone and I prepared our kids as best I could, but I felt it was best for me to be away at that point in time until I sort of finished the project and could start eating again."

The Normal Heart premieres tonight at 9 p.m. on HBO.