Trent Williams, left, and Niles Paul, center, both have noticeably different physiques after altering their diets to maximize their performance. (John McDonnell/The Washington Post)

With a late-season shoulder injury compounding a badly sprained ankle and knee, it was all Trent Williams could do to limp from one meeting room to the next last December at Redskins Park.

He was too banged up to practice; too battered to maintain his workout regimen. So it was no surprise, as the veteran left tackle devoted his work weeks to getting treatment and resting for the remaining games, that he started packing on extra weight.

Meanwhile, as yet another Redskins season lumbered to a losing finish, tight end Niles Paul was hauling in a career-high 39 receptions but getting pummeled by heavier defenders in the process.

So with opposite goals in mind, Williams and Paul vowed to re-sculpt their physiques in the offseason in hopes of staging sturdier, stronger performances in 2015.The 6-foot-5 Williams lost roughly 27 pounds, dropping from roughly 345 to 318.

Paul, a former wide receiver who stands 6 feet 1, added roughly 27 pounds, bulking up to 252.

And both did it in a smart, systematic way — with help from a team of experts — rather than the old-school NFL approach of gorging on food indiscriminately to add weight or jogging in plastic track suits to sweat off extraneous weight.

The results are stark enough for the average fan to notice at a distance. Redskins defenders charged with tackling or shedding blocks from them can surely tell. And both players say the dividends include more power, energy and confidence.

“I just feel quicker,” said Williams, 27, a three-time Pro Bowl honoree, in a recent interview at training camp. “My wind is at an all-time high. I’m stronger at the point of attack. I get to my spot faster. It just helps in every facet of the game.”

Said Paul, who was named the Redskins’ starting tight end, ahead of frequently injured Jordan Reed, for the first time since his fifth-round selection in the 2011 draft: “[Outside linebacker Ryan] Kerrigan used to treat me like a rag doll in practice. Wherever he wanted me to go, I went. And it’s not that way this year. I’m a lot more aggressive with him.”

However striking their physical transformations, neither Williams nor Paul is going to single-handedly turn a poor Redskins offense into a good one.

But assuming the players maintain their healthy habits long-term, the offseason work ought to pay dividends: Giving each a better chance of avoiding injury, quite possibly extending their NFL careers; and ideally, helping them shed unneeded pounds in retirement when morning golf games and afternoons on the couch replace football practices and game days.

In Williams’s case, the goal was to pare down without losing the explosiveness that has made him an elite left tackle.

“Every year I fine-tune my training and my preparation to be better. This year, my thing was to eat better,” Williams said.

So he consulted with Mike Clark, the Redskins’ new strength and conditioning coach, who had previously worked with Hall of Fame left tackle Walter Jones. In a 12-year career in Seattle, Jones surrendered just 23 sacks. Among Jones’s secrets, Clark told Williams, was that he shed four or five pounds each year toward the end of his NFL career to guard against excessive wear on his joints. The 6-5 Jones’s optimum playing weight was 325.

“The more weight you carry, every step you take is more pressure on the joints,” said Clark, explaining the correlation with injury. “The more weight you carry as the game goes on, the less reactive you are to the ground. You’re not as quick or explosive. It becomes harder, so you want to become lean.”

Williams then arranged a meeting with his personal dietician, Roberta Anding, the sports dietician for the Houston Astros and Rice University, and his personal chef, Tiffany Tisdale-Braxton. Anding laid out a roughly 2,600-calorie-a-day meal plan that included plenty of lean protein and vegetables, designed to get Williams safely to his goal. And Tisdale-Braxton, a former classmate of Williams’s at Oklahoma, tailored recipes and menus around the plan and started cooking full-time for Williams and one of his referrals, NFL running back Adrian Peterson, who also spends his offseason in Houston.

The first adjustment for Williams was eating breakfast, a meal he typically skipped because he is not a morning person.

“The more I looked into it, I realize that if you want to speed your metabolism up, you have to fuel your body,” Williams said. “Once I picked breakfast up, I noticed a spike in my energy level throughout the day, which enabled me to work out longer and harder.”

With Tisdale-Braxton handling the planning and cooking for three meals and two sizable daily snacks, it was easy, Williams said. The pounds fell off, but he never went hungry.

“One day I might have a couple boiled eggs, turkey bacon and fruit for breakfast,” Williams said. “One day it might be an egg-white omelet. She switched it up for me; made it convenient. Soon as I came out of my room, breakfast was ready. I’d eat breakfast, then I’d go work out. Come home, lunch would be ready. Eat lunch, then I do my second workout or whatever. Then I would come home and dinner would be ready.”

Said Tisdale-Braxton, whose business, Tisdale23 Catering, is named in honor of her late father, NBA star Wayman Tisdale: “Athletes are realizing that there are ways to maintain a larger muscle mass without putting terrible things in your body. You don’t have to be eating as much as you can eat. You can still eat a high calorie count but have it be healthy.”

Unlike Williams, Paul, 26, didn’t sign a six-year, $60 million NFL contract. Personal nutritionists and chefs aren’t in his budget. But he found the expertise he needed in bulking up without sacrificing speed at Redskins Park, where he worked closely with Clark on a new weight regimen and with the team’s chefs on healthier eating.

“My goal was to put on a little bit more weight so that I stood a fair chance against the bigger guys in the league, the bigger guys on our team, the defensive ends,” Paul said. “It had to be good weight.

Instead of skipping breakfast and eating one or two meals daily, Paul switched to three and four meals a day. He was also urged to eat as many healthy snacks, heavy in carbohydrates and protein, whenever he wanted and particularly after workouts.

“We told him not to get hungry, just to eat throughout the day — either a protein shake, a Greek yogurt,” Clark said. “When he’s getting ready to turn the lights out, eat the yogurt and go to bed.”

Under Clark’s direction, Paul shifted his focus to Olympic-style weightlifting, which focuses on building lower-body explosiveness or “BBH,” for short.

Clark explains: “I tell players all the time, ‘You should look better going than coming! Your back, butt and hamstrings better be really, really strong. BBH!”

In Paul’s case, he squatted 515 pounds last season. Now, he’s squatting 605.

“I feel stronger. I feel like a better player,” Paul said. “I feel like I’m not getting manhandled by the bigger guys anymore. I feel like I’m a true tight end.”