Cole Sprouse Says He Lost 25 Lbs. to Play Terminally Ill Teen in Five Feet Apart

The Riverdale star reveals the mental and physical preparation he did to embody the physical limitations of cystic fibrosis

Photo: CBS FILMS

In taking on his newest role — playing a lovestruck teen living with cystic fibrosis in Five Feet Apart — Cole Sprouse did extensive research about the disease in order to properly and respectfully portray how it impacts those living with it.

“Cystic fibrosis is not really as in the public eye as it probably should be,” Sprouse tells PEOPLE in the latest issue. “It’s one of those illnesses that everyone sort of knows the name of but doesn’t really know the gravity of.”

The actor, 26, says that he and costar Haley Lu Richardson and director Justin Baldoni (Jane the Virgin) put a lot of time into the physical and mental aspects involved — including weight loss.

“We built this whole nutritional regimen dedicated to embodying the physical limitations of cystic fibrosis. I lost 25 pounds for the role,” he admits. “Everything we had to learn was covered in a mortality that was debilitating. But we were lucky enough to work with not only medical professionals who are extremely trained with cystic fibrosis, but also with patients themselves. I feel pretty well-versed about cystic fibrosis now.”

Cole Sprouse. MediaPunch/REX/Shutterstock

Cystic fibrosis is a genetic disorder that generally affects the lungs and can cause difficulty breathing and coughing from a build-up of mucus.

Sprouse says he’s proud that the movie is informative. “We made sure to be as accurate as possible,” he says. “And for us, the greatest feedback has been from the CF [cystic fibrosis] community going, ‘Yeah, we know that this is still a Hollywood production but it’s very clear that production has put a lot of attention to detail in how this thing really affects our lives.’ And that’s the badge of honor that we want.”

The Riverdale star admits that despite the challenges and research associated with playing someone suffering from a serious illness, tapping into his romantic side wasn’t difficult at all.

For much more on Sprouse and his new movie, pick up the latest issue of PEOPLE on newsstands Friday

“I’m a huge fan of the romance genre. I’m always swept away within that sort of thing,” he says. “I grew up reading Japanese romance manga for young girls — at the time, it was for young girls but I made it my own. So, I’ve always kind of had this fondness for that genre in general. Also, we wanted this movie to feel sort of like a beacon of hope, and not feel debilitating. We’re certainly pulling on the heart strings, but we had curated the script and the performances in a way to make it feel hopeful, which we found quite important for the CF community and not just for the audience.”

Five Feet Apart is now playing in theaters.