Jake Gyllenhaal Refused to Eat Even 'One Chip' During 'Strict' Diet in Order to Stay Toned for 'Road House' Film

Jake Gyllenhaal fully committed to his starring role on the new Prime Video film Road House.

Appearing on the Thursday, March 21, broadcast of This Morning, the 43-year-old sat down with anchor Sian Welby to share a glimpse inside the intense lifestyle change he underwent in preparation for his portrayal of Elwood Dalton, a former UFC fighter who becomes a bouncer at a dive bar in the Florida Keys.

Ahead of the film, Gyllenhaal — who stars alongside UFC fighter Conor McGregor, 35 — had a diet regimen so strict he wouldn’t even allow himself to have "one chip" in an effort to maintain chiseled abs and a tight torso for the action-packed movie.

During his talk show appearance on Thursday, the award-winning actor described a specific scene from the film — a reboot of the 1989 cult classic starring the late Patrick Swayze — in which his character is supposed to be indulging in some grub.

"If you really look. I don't eat the tacos. You see me take the plate and I say thank you and then the scene cuts you never actually see me take a mouthful," Gyllenhaal explained of how intense the diet truly was.

"I was on a strict regimen — one chip would have done the whole thing," he revealed.

Aside from limiting his food intake, Gyllenhaal also had to worry about staying in shape muscle wise, as his body type needed to look realistic next to McGregor, a former Ultimate Fighting Championship Featherweight and Lightweight Champion.

"I was like this is really cool but I was also just totally terrified. I was teaching professional fighters, who could really kick my a--, how to kick my a-- so that people really buy it," he explained.

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Gyllenhaal continued: "Their ability to judge distance is unlike anyone else, [so] to be working with someone who can do that, there's a safety to that too."

The Brokeback Mountain actor further dished on what it was like to act out a fight against McGregor during a guest appearance on The Tonight Show earlier this week.

"There was a lot of training," he told host Jimmy Fallon. "Conor McGregor's in the movie with me and when I got word that he was gonna be doing it, I was super psyched cause they chased him for a long time to play the part. But then I got totally terrified and I thought, 'Oh god, I actually have to fake fight this guy and I gotta look like I can.'"

"I stayed in pretty good shape, but we trained for two months, pretty hard grappling, a lot of MMA and then also just like getting in shape, you know?" Gyllenhaal concluded regarding how he prepared like a real-life fighter ahead of the film.