29/06/2015 08:31 BST | Updated 29/06/2015 08:59 BST

EXCLUSIVE: Wimbledon Champion Novak Djokovic On Drugs In Sport, The Diet That's Changed His Life And His One Guilty Pleasure

Novak Djokovic has spoken of his frustrations with professional athletes who use drugs, calling their actions “unsportsmanlike, not what sport is about, and completely unfair to all the guys who are doing it right”.

The Wimbledon champion, who begins his defence of the Mens Singles title this afternoon on Centre Court, explains exclusively to HuffPostUK that he understands all too well the demands made of athletes operating at this elite level, but that he has found another way to achieve the fitness he requires.

He tells us: “As a professional athlete, I identify myself with all the professional athletes, especially the tennis players, because I know what they go through, and how much commitment, dedication, sweat you have to go through to reach certain heights.

Novak Djokovic has transformed his game and whole way of life, which he explains is holistic

“I’m not just talking in a physical way. I’m talking about a very holistic approach, you are going to undertake a series of disciplinary measures with yourself, with people around you, and how you’re going to organise your life, in order to get the best out of you and your abilities.

“Of course, I am frustrated and disappointed when I hear or see that certain athletes are using prohibited substances and have been doing it for a while.

“It’s not sportsmanlike, it’s not what sport is all about, and it’s completely unfair to all the guys that are doing it right, that are avoiding that."

While Novak emphasises he has no knowledge of anyone using drugs in professional tennis – “I’m not paranoid, I don’t go looking, I stay away from all of that” – he puts the decision, ultimately, down to a personal choice each athlete, in any sport, must make…

“I respect their choice. Everyone has the right or freedom to choose whatever they want to do in their life, but they have to be aware of the consequences it’s going to make on their reputation.

“I try to keep it as clean and natural as possible, I believe in nature, I believe in hard work, I believe in mental strength and dedication. It has worked for me, but everybody’s different.”

Fortunately for Novak, the way that works for him involves instead a menu of fresh, healthy food, designed to give him enough energy to, as he puts it, “get through the day”.

The restrictions on his diet have become famous – as well as gluten-free, he swears off dairy and, as much as he can, refined sugar. He tells me cheerfully, “I basically don’t eat anything at all.”

Novak Djokovic begins his defence of the Mens Singles title today on Wimbledon's Centre Court

But, as he ably demonstrates in a slightly surreal cooking demonstration to a few guests of one of Wimbledon wine sponsor Jacob's Creek in a marquee perched near the new No.2 court, what Novak can cook up within these confines is a marvel. We’re treated to gluten-free pasta with prawns, tomato and kale, plus a delicious green salad and some quinoa. With food this good on offer, I can start to see how Novak can give up ready meals and fast food so easily. He says himself he hates food like that, and can sound properly evangelical on the subject of connection between diet and improved health, vitality and balance, even sounding properly new-Agey on his “smooth flow of information between body and brain – it’s a state that’s amazing to be in.”

With the Wimbledon trophy still burning a hole on his shelf, for another fortnight at least, and eight Grand Slam titles to his name in total, I am no one to argue with any of this.

There are two other surprises on meeting the Men’s Champion. The first is his relative slightness compared with the bulked-up bods of two of his three great rivals Rafa Nadal and, latterly, Andy Murray. In his wide-shouldered blazer, Novak looks positively Flat Stanley-esque sitting opposite me. He readily concedes, “I’m not a muscular type of guy, everyone’s different. I just try to find an optimum strength and feeling throughout the day.”

The other unexpected aspect is the depth of his discourse, especially considering it’s happening in his second language. The chats between him and current coach, Boris Becker, another of tennis’s great modern philosophers, must be mind-boggling. Novak’s eyes glitter with far more fun than his polite but implacable on-court persona would suggest. But he is deadly serious about looking for more than one-word answers when it comes to success…

“I understand that people today always want to find a simple explanation for success, not just in sport but just in general in life,” he ponders.

“They ask me, ‘What are you drinking? What is the secret? How can you put it in the most simple way? Why did you succeed?’

“Everybody was obviously emphasising the gluten-free diet as the secret of my success, but it’s not. I believe in a very holistic approach, not just to food but to life in general.

“You have to put in order a lot of different aspects to your life in order to be healthy and get the best out of your abilities and talent.”

I have to say, this all pretty inspiring stuff, coming from this polite, utterly focused, physically balanced chap, sitting opposite me and perched on top of the sporting world. But obviously, because I am not so disciplined, I can’t resist sniffing out a foot fault. Is there a guilty pleasure in there somewhere? Please say yes. And, bless him, he really tries to think of one…

“Okay, I can give you a one-word-answer for that,” he agrees eventually. “Pizza.” But this took a while, and I’m really not convinced.

Novak Djokovic was talking to HuffPostUK for his #MadeBy campaign in conjunction with Jacob's Creek. He begins his Wimbledon campaign today on Centre Court at 1pm. Wimbledon coverage can be found on the BBC's multiple platforms - more info here.