How Jeremy Allen White and Zac Efron Got Shredded for 'The Iron Claw'

When it comes to diet, those requirements vary greatly by person. But generally speaking, putting on the kind of muscle that Efron and White did requires eating more calories a day than your body needs.

"You should consume a slightly higher number of calories than your body needs to function during the day," Morgan said. "You should consume a maximum of 20% more calories than your body needs per day to increase your weight gain by roughly 0.5% of your body weight each week."

For most men, this means around 2,750 calories a day to begin bulking up, but that doesn't mean you should be eating every potato chip, hamburger, and pint of ice cream in sight; better results will be achieved when eating as clean as possible and making sure your body is getting the appropriate nutrients.

Commonly referred to as "macros," there actually is an ideal ratio of macros that you should be aiming for when trying to get ripped: 30-35% protein, 45-60% carbs, and 15-30% fats.

On the workout front, Morgan points to some specific bulking workouts that Zac would have done in order to optimize his strength: Overhead squats, pull-ups, back extensions, weighted leg raises, and the incline bench press.

In addition to what you're eating and how you're working out, there's another vital component to looking your best: Recovery and sleep.

"While you sleep, your body releases protein-building amino acids at an increased rate, which is crucial for anyone looking to develop bigger and stronger muscle," explained Morgan. "Zac would need to get at least seven hours of sleep to optimize his muscular hypertrophy."

When it comes to Jeremy Allen White, GQ enlisted the help of Chris Antoni, a fitness trainer behind Tailor Made Fitness.

To get a physique like White's, Antoni recommends a classic high-protein diet consisting of mostly chicken and fish, though red meat twice a week is also okay. Better than beef, he says, is bison, which has fewer calories and higher amounts of B-12, iron, and protein.

But getting a body like White's isn't as easy as eating a lot, working out a lot, and sleeping a lot. "That kind of body is not easy to build or maintain," he warned. "I'd be very surprised if he doesn't have a personal chef, someone making his meals and keeping in him check."

Looking at White's body, Antoni suspects he's taking advantage of higher-rep, lower-weight workouts, which he says build muscular endurance and helps give him that lean look without looking bulky and oversized.

Pointing to White's much-loved look from "The Bear," in which his biceps pop under his white t-shirt, Antoni thinks that he's probably doing a lot of dumbbells. "His shoulders are in good shape too," he added, "and obviously the bigger your shoulders, the more muscular your arm looks. I'd say he's doing a lot of isolation exercises like shoulder press, lat raise, and front raises to achieve this, alongside bicep curls and tricep rope pull downs, hammer curls."

Whatever it is that White is doing to keep himself looking like a full meal, one thing's for sure: We hope he never stops.