The Knowles truth and nothing but the truth...

Nick Knowles is looking a lot trimmer these days after losing two stone in two months.

“One morning I looked at myself and went, ‘Oh my God, when did that happen? You have to sort it out!’”

He basically cut out bread and dairy and hopped on the cross-trainer for an hour four times a week, while reading his Kindle (a present from wife Jessica).

“It’s amazing how quickly you can lose the weight,” he notes, though it wasn’t only his moment of truth in front of the mirror that motivated the changes, or his TV work (“Though TV does make you look heavier, so there is a responsibility to look sharp,” he says).

“Mainly, it was what he calls his duty to his wife to keep himself “looking decent”.

“I think you have a responsibility to your partner to try and keep looking healthy and in good shape,” notes Knowles – and that has nothing to do with the 25-year age difference, he insists.

“The only time we even consider the age gap is when journalists ask about it, and maybe the general public, but nobody who knows us ever brings it up.

“I mentioned it to Jess the other day and she said she’d completely forgotten about it.

“I’m still young and doing 30 hours of TV for the BBC every year.”

This includes the quiz show Who Dares Wins, the hugely successful home renovation programme DIY SOS, which launched back in 1999 and The National Lottery: Break The Safe, which returns this month for another series.

Hailed as BBC One’s highest rated entertainment show of last summer, it sees three couples battle it out in a question and answer session, to determine who will be the last pair standing, and ultimately attempt to ‘break the safe’ and win up to £100,000.

“The thing about quiz shows is it’s actually about the people, not about the quiz, so I spend a lot of time, making sure the personalities and characters come out.

“That way, people engage with them and care whether they win or lose the money,” explains Knowles, who reveals that he and the producers made the decision early on that he wouldn’t be forewarned of the final result.

“We decided not to, on the basis that I can live the moment with them [the contestants], so for me, it’s terrifying,” he jokes.

His ‘everyman’ style is part of Knowles’ appeal, something he attributes to his “humble” beginnings on a council estate in West London. “It’s not like I was born with a silver spoon in my mouth.

“I do understand how difficult it is and my brother and sisters work harder than me to make ends meet, and I see that every day.”

Following school, he undertook various jobs, including labouring and then began his TV career in the Beeb’s documentary features department.

He spent two years in Australia working in a newsroom before moving to America, and then returning to the UK as an editor and reporter.

It was only in 1997 that he branched out into presenting, when he hosted daytime chat show 5’s Company.

“I think having [initially] done all the jobs in television other than presenting, it makes you realise how hard everyone’s working to make you look good. I think a lot of presenters forget that,” Knowles admits.

“I fell into presenting, which is nice, because I’ve never been desperate to hold onto it and I can be a lot more relaxed presenting the show, which people seem to like.”

Television work isn’t his sole focus, either.

He and Jessica opened an antiques shop in Eton last year.

Although they were forced to close after flooding, they “found a lot of our work came through online, so we’re continuing to trade”, says Knowles, who’s also written a book and has a film in production.

“It’s a movie about older people retiring and acting badly,” he reveals.

“Which is how I hope I will be when I retire.”

The National Lottery: Break The Safe begins on BBC One tonight.