Is Nick Jonas on a mission to make every one of his fans faint dead away? Because that's kind of what's been happening every time we see a new shirtless photo spread of the 'Jealous' singer -- and his recent shots with Details magazine are no exception.

Of course, the 'Kingdom' star looked completely drool-worthy in the muscular photos, flaunting his intense dedication, hard work and those killer muscles in the sizzling pics. But getting a body as in shape as his doesn't come easy -- and Jonas revealed just what it took to bulk up.

"I don't have the luxury of eating whatever I want whenever I want anyway, because of my type 1 diabetes, so I have been conscientious about food for a long time," Nick explained to the magazine, revealing that he had to put on some heavy muscle for his role as an MMA fighter in the DirecTV drama 'Kingdom.'

"I had about six weeks to put on 12 to 15 pounds of muscle before filming started," he explained. "I went from consuming about 3,000 calories a day to 4,200! Paleta, a food-delivery service, sent me three meals a day and snacks. It was an incredible way to know that I was getting what I need to build muscle and not have to think about it."

So what exactly did Jonas consume while gearing up for the show?

"Breakfast was usually an omelet with veggies and cashew cheese, a turkey-meat patty, and some fruit; lunch and dinner would be lean protein, veggies, and nuts; snacks consisted of things like snap peas with peanut sauce," he revealed, adding that he did not drink while training for 'Kingdom,' though he now "keep[s] it classy with Coors Light."

While he describes his 'Kingdom' figure as "Hulk-ish," Jonas said he is now focused on a leaner figure for his self-titled album and tour.

"Now that I'm on tour for my album, I've leaned out about 10 pounds from what I'd gained. It's been fun to change my physicality," he said. "My meal plan came down to about 2,500 calories, and the portions got really small. I exercise only three or four times a week," he revealed, as opposed to the three times a day when he was training for the show.

Despite all of his hard work, dedication and hours put in at the gym, Jonas explained that he is still not someone who loves to get his fitness on.

"I'm not the kind of person who wakes up in the morning and can't wait to work out," he admitted. "I kind of dread it, actually. I see it as a necessary evil."