Openly gay Matt Bomer left his husband and three children to prepare for his role in The Normal Heart.

Director Ryan Murphy's adaptation of Larry Kramer's Tony-winning play premieres Sunday on HBO.

In the movie about the early days of the AIDS pandemic in New York City, Bomer plays Felix Turner, a closeted fashion reporter for The New York Times.

Speaking to HIV-Plus, Bomer, the 36-year-old star of USA's White Collar, said he lost at least 40 pounds for the role.

“I felt a tremendous responsibility in playing this role, and part of it was creating that physical reality for the second half of the film,” Bomer said. “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. 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 film's all-star cast also includes Mark Ruffalo, Taylor Kitsch, Jim Parsons and Julia Roberts. (The film's trailer is embedded on this page. Visit our video library for more videos.)