The Chase star Mark "The Beast" Labbett has much to be proud of as he nears his 60th birthday. As well as being the world's most successful Chaser, and a fantastic father, he's also on the brink of celebrating becoming half the man he was. The 59-year-old quiz master, who joined ITV's The Chase in 2009, has undergone a significant health transformation in recent years after being diagnosed with Type 2 diabetes - and has now lost half his body weight. He confessed to OK! magazine that "sugar" was his downfall, but now, as a father to seven-year-old Lawrence from his marriage to ex-wife Katie Labbett, he's more determined than ever to stay healthy, Gloucestershire Live reports. When asked why he still loves being on The Chase after 26 years, he said: "Pride and ego are the whips that drive me. I like being regarded as pretty clever, I like possibly being the best in the world at what I do, and that's what drives me. "I never want to be just making up the numbers." He added: "I'm literally the world's most experienced Chaser. I'm the only one who's done it in three different countries . I keep looking around when I'm on set and thinking, 'They're paying me to do this!'. "I'm in Hollywood, working for a prime-time American show. I've just been introduced to David Hasselhoff , who's wandered in to steal some donuts from our craft services table" Not bad for a fat old maths teacher . You’ve lost a lot of weight in recent years… I’ve been a yo-yo dieter and my heaviest was about 29st, then I got fit and was down to about 25st. But I’ve always actually been surprisingly fit. Even at 25st I could do a proper pumping hour on the cross trainer. I’ve been meaning to go and get a set of bathroom scales . My guess is about 18st, maybe in the 17s. I’ve got roughly the same physique as I had when I was playing rugby at 18 years old, but I’ve got less muscle so that might take it down even more. Sometimes I look and go, “Blimey, is that me?” But the one thing about being a very big person, and especially a very big man with a big frame, is you can carry a lot of weight without really noticing it. The trouble is, I had a tonne of visceral fat, which isn’t good for you at all, and that’s why I was so heavy but relatively slim for my height and build . Normally, if you see a 30st man they’re quite obviously 30st, but I was carrying it internally. Yes. I’d lost a bit of weight before then, but last winter I had my first real attack of arthritis and it was a shock to the system because up to that point you think you’re immortal. Then suddenly, when you struggle to walk up stairs, you realise you’re not. I’d been gradually letting my glucose levels slide and enjoyed too many cheats, so when I put the monitor on I was shocked by my glucose levels. It’s been a real eye-opener. I’ve been doing panto with it on and you can almost see the glucose level in real time. It’s made me realise I’ve got to be far more disciplined with carbs and sugars. I have no ‘off’ button, in the same way for some unfortunate people when it comes to alcohol, they can just keep going. I could have a couple of chocolate bars and then reach for another. Yes. One of my life goals, because I was a more mature father when Lawrence appeared, is to see him graduate. He’ll be 21 when I’m 71, 72, and that’s my mission. I’m just happy he’s a well-adjusted young man. He’s inherited my maths ability, which I’m not upset about either. He’s healthy, smart and tall – what more could you want? I’m really content with where I am. I’m loving being a dad – it’s nice to be able to provide for him. I love 99% of dealing with the public. They always say never achieve all your ambitions because then life gets boring, but my big ambition is, before I get too much older, a chance at hosting my own quiz show. I’m hoping one day ITV will say, “Mark, your time has come.” Until that happy day, I’ll keep working hard for them.