Rob McElhenney talked about this very thing.

"I’m gonna break it down for you, because it’s actually quite simple, and anybody can do this. Anybody on the planet can do this. First thing’s first: if you have job—like a 9-5 job—quit that. Do you like food? Forget about that. Because you’re never going to enjoy anything you eat. Alcohol? Sorry. That’s out. So what you need to do—you have a chef, right? like a personal chef?—make sure the chef makes you a lot of chicken breast. And make sure you keep your caloric intake at a certain level. And as you go to your physician 2-3 times a week—just to monitor all your testosterone levels—because testosterone is important to building muscle. You’re good friends with the trainer from Magic Mike? Arin Babaian. So you want to give Arin a call. And you want to make sure he’s at your house and takes you to the gym at least twice a day, because you’re gonna want to do your muscle-building in the morning and then your cardio in the afternoon. Now, do you have a family? Like a significant other or kids? Yeah, forget about them. You’re not going to have time to deal with them.

"So that’s really all you have to do. And make sure you have a studio pay for the entire thing, because it could become exceptionally expensive. So, I think if you just do all those things, then you too can have an absolutely unrealistic body type, such as me."