At an age when most soccer players are winding down, Jermain Defoe is enjoying a career revival.

And the 34-year-old striker credits his endurance through trying to abide by a vegan diet.

"It's about eating the right things," Defoe said, "but it's difficult when I visit Mum and she puts every meat out on the table."

Ditching meat and dairy is part of a fitness regime, including visits to cryotherapy chambers, that Defoe believes helped to earn him a first start for England in four years.

The Sunderland forward marked his return from international exile on Sunday in the way he knows best, by scoring the first goal against Lithuania in a 2-0 World Cup qualifying victory.

Far from contemplating the end of his playing days, Defoe is doing everything possible to extend his 56-game England career, even if that means sacrificing the food he relishes.

"The way the game is changing, the demands on the players are so high with the intensity of the games these days," Defoe said. "The key thing for me is how you recover after games to give yourself the best opportunity to perform in the next game.

"I seem to have got that to a tee. There's a lot of things I do away from training, away from playing that help me perform on match days."

Defoe's career appeared to be on the wane when he moved to Toronto in 2014 to play in Major League Soccer but he returned to the Premier League within a year.

The effects of the new dietary regime are unclear but what is indisputable is Defoe's impact on the field. The England goal was Defoe's 15th in 32 games for club and country this season — and there are still two months remaining. With an increased workload, Defoe is close to overhauling last season's goal tally of 18 in 34 games for Sunderland.

According to Defoe, the plant-based diet has diminished his fatigue near the end of games.

What was the inspiration for emulating heavyweight boxer David Haye and adopting a vegan lifestyle?

"My girlfriend said to me, 'You've got to do it,'" Defoe said. "She puts on these documentaries."

Specialist planning from nutritionists remains essential.

"I wouldn't recommend a vegan diet straight away," said Rick Miller, a London-based clinical and sports dietitian . "If someone wanted to take a more plant-based approach that's fine. I wouldn't actively say avoiding all meat or animal products is entirely necessary. It's about a varied diet."

Through supplements, vegans have to compensate for the protein and calcium they aren't ingesting from animal-based products.

"Sportspeople need protein to recover after exercise otherwise they are at risk of losing muscle mass," Miller said. "It's also about the quality of protein. The building blocks of proteins are amino acids and plant-based proteins don't contain the full spectrum of essential amino acids.

"Most calcium tends to come from dairy products like butter and yoghurts. In vegan diets you have to be more careful and look at nuts, seeds, and certain vegetables to get enough calcium. It's not always as easily absorbed."

Miller, though, doesn't discourage athletes like Defoe from turning vegan.

"People tend to experience an improvement of wellness through eating more fiber and vitamins — particularly C, a potent antioxidant," said Miller, who is also a spokesman for the British Dietetic Association. "That can help with recovery. You also might be eating more essential fatty acids through nuts and seeds that improve nervous system functions and blood fat levels. People on plant-based diets also tend to live a bit longer."

Playing longer is the immediate focus for Defoe, keeping bottom-placed Sunderland in the Premier League and making it to the 2018 World Cup with England.