The Chase fans were stunned by The Beast's weight loss on This Morning today.
The brain box, 57, also known as Mark Labbett, was talking to hosts Dermot O'Leary and Alison Hammond about his life before fame as an 'overweight maths teacher'.
But it wasn't his backstory which sent fans into a frenzy.
Many viewers took to Twitter commenting on how much weight the star has lost.
"Wow @marklabbett has lost so much weight, but he looks great,' remarked one.
Another said: "Mark looks incredible after dropping the weight. Watching his interview he seems like such a lovely guy."
While a third agreed, tweeting: "Mark Labbett has lost some weight - looking good."
Mark has lost a staggering amount of weight over the last few years, by making small changes.
The quiz star has managed to shed a whopping 10st, which he said was kick-started by the coronavirus lockdown.
Best known for being brain box The Beast on the hit ITV daytime quiz show, Mark has been on a mission to lose weight for years after tipping the scales at 29st at his peak.
At that point his weight started to affect his health, as he admitted he was 'on the verge of getting high blood pressure pills', according to The Express.
Mark managed to lose a few pounds over the next few years, but reckons it was just before lockdown that he started losing weight dramatically.
The father-of-one said: “Several factors came together nicely and the weight has just fallen off. The principal thing has been running after a hyperactive three year old in lockdown when the nurseries were shut.
"Instead of going to the fridge for a bit of late-night snacking all I could do was just collapse on a heap on the bed."
Mark changed up his diet and instead of eating 'pub meals', he opted for a high protein diet as well as reducing the amount of sugar he consumed.
The quizzer tested positive for Covid during the pandemic, which he admitted also helped him on his weight loss journey.
The star lost his sense of small and taste for two weeks, causing him to eat less than he usually would
Mark has now managed to get himself down to 19st, while he stands at a towering 6 foot 6.
Reflecting on how much his life had changed for the better over the years, fans flocked to social media commending Mark on his interview on This Morning.
Several mentioned how well he came across - with many saying the star should have his own show.
