1,200-Calories-a-Day meal plan

Watt's body lagged behind his mind, though. Having trained the Houston Texans defensive end since high school, Brad Arnett noticed something was wrong during a workout back in February. Watt also noticed. He knew his body well enough to know it just didn't feel right.

"My body was grabbing for something that wasn't there, " Watt said. "It was trying to fuel itself with no fuel."

What was missing?

Fat. Cheat days. Tasty things.

If he ate eight chicken breasts in one meal, Arnett suggested he wrap three of them in bacon. Daily. That meant adding mashed sweet potatoes, more pasta, fish, olive oil and coconut oil in his cooking and avocados.

"I started crushing avocados, " Watt said.

His calorie count rose to somewhere between 6, 000 and 9, 000 calories per day, depending on how active he was each day. Watt opted to keep his own meal plan a secret, but it would take about 50 slices of bacon, 20 chicken breasts and 13 whole avocados to reach 9, 000 calories.

J.J. Watt's diet, which he thought would help him stay strong and lean, ended up sapping him of much-needed fats. Amber Searls/USA TODAY Sports

Weekly, that meant the glorious return of one cheat meal, something Watt thought he had to cut out. The cheat meal's triumphant return came in the form of brunch.

"I love brunch, " Watt said. "Brunch is my favorite meal. I went there (to his favorite brunch spot in Wisconsin), had brunch, had a massive potato pancake omelet, which is an omelet inside a potato pancake. Then I had stuffed French toast with berries and stuff. My cheat meals aren't even that exciting. That was my cheat meal. The omelet is still pretty darn healthy. The stuffed French toast was the cheat meal, but that was delicious."

He loves barbecue, too.

Watt has struck up a friendship with local chef Ronnie Killen, owner of Killen's Barbecue, named one of America's top five barbecue joints by the Food Network. When Watt eats lean, Killen sends him smoked turkey and lean cuts of brisket. Going into Killen's Barbecue isn't an option during non-cheat times because Watt has trouble resisting carrot cake, banana pudding and bread pudding.

"It's funny, because you can tell when he's in serious mode and when he's kind of relaxed, which, he's hardly ever relaxed, " Killen said.

Killen noted that Watt doesn't like sauces much. He likes simplicity. It's part of the reason Watt says he doesn't have a chef. He tried one for a few weeks, but he prefers to cook his own meals. When Killen opens a burger place soon, he will have a No. 99 burger on the menu: a turkey burger with ground-up mushroom inside it. Moist, lean and simple, just the way Watt likes it. Killen's never named a menu item after an athlete before.

As Watt spoke about his nutritional revelations, he sat on a table in Richmond, Virginia, minutes after practice, still in uniform. He gulped down a chocolate post-workout shake before the interview, and that was only the beginning. That day was actually a cheat day - he'd bought Krispy Kreme doughnuts for the team to celebrate punter Shane Lechler's 39th birthday.

Watt isn't the only elite athlete who has to eat this much. In 2008, swimmer Michael Phelps said he consumed up to 12, 000 calories per day while training for the Beijing Olympic Summer Games. Still, reaching his somewhat fluid calorie marks isn't easy for Watt.

"It's literally, if I'm not working out, I eat the whole time I'm not working out, " Watt said. "It's exhausting. You have to force-feed. You have to force yourself to eat food."

Since entering the NFL, Watt convinced himself that food was just fuel, that taste didn't matter and that this would perfect his diet. In his mind, a lean, low-carb diet was what his body needed to be as strong and lean as he wanted to be. He attacked it with the discipline that's helped him turn into a two-time defensive player of the year and league MVP candidate.

"Everything in you wants to eat the stuff that tastes good, " Watt said. "And trust me, I love good food just as much as anybody. It's just like everything else. In the early days, there's days when you don't want to go to the gym. There's days when you don't want to wake up early. There's plenty of days when I don't want to eat chicken breast and broccoli and rice, but I know what I have to do, and I know the sacrifice I have to make."

Only he began to sacrifice too much. The diet led to a dip in energy levels that caused Arnett to sit down with Watt to review the importance of fat and carbohydrates.

"It's OK, you're not going to fall off the face here, your body [composition's] not going to jump 5 percent the next day, " Arnett said. "Just making subtle changes. It made a huge, huge difference."

Within days, Watt's energy returned. The fat was helping him absorb the nutrients from his other meals and turn those into much-needed fuel for grueling, self-imposed two-a-days.

There was a time when Watt thought he'd never get to eat anything tasty until he retired from football.