In his hideaway on the Dutch-Belgian border Tyson Fury is reshaping that gigantic 6ft 9in body in preparation for his rematch with Wladimir Klitschko.

Ever the walking contradiction, never shy of controversy, the Gypsy King who defied all odds to end Klitschko’s decade-long reign over world heavyweight boxing has given up eating meat yet is building muscle in expectation of inflicting a knock-out in next month’s rematch.

‘It will be a different fight in Manchester,’ says Fury, who bamboozled Klitschko with a giddy mixture of mind games and amazing twinkle-toed agility on the night in Germany when he won most of the world heavyweight titles.

At the press conference in March, Tyson Fury proudly shows off his belly after gaining weight between fights

Fury faces Wladimir Klitschko at Manchester Arena in a rematch for WBO, WBA and IBO heavyweight titles

‘Klitschko will have to try something different and I must change to be ready for him.

‘It will be explosive and I must add power to my athleticism. So it might seem odd that I’m cutting out red meat. I used to love sitting down to a huge steak but now it’s seafood and fish salad.

‘I used to tell myself that a cow is stronger than a fish. Now when I’m in a restaurant and someone on the next table orders a juicy side of beef I’m disgusted that an animal has been killed to feed him.

‘I’m a pescatarian now. Not a vegetarian because I don’t like many vegetables. Only sweet corn, mushy peas and potatoes. And I feel fitter and sharper on a diet of fish. Not bloated any more. I’m no longer like the lion whose gorged himself on a kill and then has to go and lie down in the sun to sleep it off.’

Even so, he is putting on weight so as to withstand the higher ratio of aggressive punches he anticipates Klitschko throwing on July 9.

‘I’m trimming fat but adding muscle,’ he explains. ‘It’s a balancing act. I can’t go under 10 per cent body fat or I’ll feel the punches. But assuming he comes out throwing this time I will need the power to knock him out.

‘Forget the meat. I’m bigger on the chest and arms than I’ve ever been in my life, up top. But I’ll still be able to move despite being half a stone heavier than last time, at just under 18 stone.’

Fury’s physical condition is in marked contrast to the blubber he was carrying – and proudly exposed – five weeks ago at the press conference to launch this rematch.

He says: ‘I don’t believe in training every day of the year, like Wladimir who does it so he can keep boxing at 40. I enjoy every minute of putting on three or four stones with the Chinese and Indian takeaways.

Fury insists he feels fitter and sharper after ditching red meat in favour of a seafood diet

Fury stunned Klitschko in December to snatch the heavyweight belts and end the Ukrainian's dominance

‘It also costs me a fortune when I go to restaurants charging a grand a plate. Although to be honest I can’t tell the difference from a £3-a-plate dinner when I smother a pile of food with gravy.

‘I do this because I can go from being a fat pig on the booze to feeling really fit. Go from champagne and vodka and beer and lobster dinners to winning a world title.

‘I showed off my belly at the press conference to show that I’m a normal human being and that you don’t have to be a robot to be a world champion. I believe you have to be unfit to get fit.

Now, five weeks into eleven weeks of Spartan preparation, this fighting man who was recently teasing us by saying he was fed up with boxing and ready for premature retirement is deep not only in dedicated training but virtual isolation.

‘Holland has always been good for me,’ he says. ‘Here I’m away from every distraction. Just me and my team. Not visitors. No family. Only the occasional face time on Skype with the kids and a few texts with the wife. It’s a hard grind but it makes me focus.

Fury (right) celebrates wildly after his points victory over Klitschko in Germany last December

Fury has isolated himself from the outside world as he trains to be ready for the rematch with Klitschko

‘I train morning, afternoon and evening. Sometimes I hate having to go on the cross trainer for an extra hour at night. But I put a towel over the timer and thnk about boxing and how I’m going to beat Wladimir again. Put a second defeat on the man who was the best heavyweight in the world until I beat him and still the second best heavyweight in the world.

‘If someone as different as me had not come along to take his titles he would have cruised on to another 20 successful defences. Because none of the other heavyweights out there are anywhere near his class. He could play with any of those bums.

‘I have to concentrate on Wlad. He will be more dangerous than in the first fight. A wounded animal is always dangerous. And I have to work harder this time because I am the champion.

‘I have achieved my childhood ambition by winning the titles. But it’s easier to become champion than stay champion. It’s not my dream any more but it is about living the dream.’

Klitschko, he knows, could still be a threat to that state of Karma. But Fury says: ‘He would beat anyone else but me. I have destroyed him mentally and physically. When we meet he will see that I am massive. And I will knock him out. I’m a bull.’

Then he smiles at the thought of how he has become one without devouring a single cow.