Mitch Benn’s audiences at the 2011 Edinburgh Fringe received something of a shock when the singing comedian they had come to see walked onstage.

Between January and August that year the star of BBC Radio 4’s The Now Show had lost ten stone from his original 25 stone (160 kg).

“A lot of people didn’t know who I was,” laughs Benn.

“All anyone was asking me was why my show wasn’t about my weight loss. I thought it was horribly premature – I had only just taken the weight off and the hardest part is to keep it off.”

With their advice in mind, Benn came back the following year with what is his most personal show to date – Reduced Circumstances.

“It was quite an interesting experience – it felt like my first proper Edinburgh,” says Benn, who made his name with his topical songwriting – most famously the YouTube hit Everything Sounds Like Coldplay Now.

“How I lost the weight is the least interesting part of the story. I signed up to a regular diet programme and it came off.

“Weight loss isn’t a technically difficult thing to do – it’s about what you put in with food and what you put out in terms of energy.

“At the same time I’m not going to pretend it wasn’t difficult. I wanted to look at why it took so long and why some people never get it together.”

He admits there wasn’t a moment or personal crisis that encouraged him to start dieting.

“I wasn’t given a talking to by a medical professional that hadn’t been happening over the last few years,” he says.

“I just realised I was over 40 and 25 stone, and if I didn’t try to do something now something major was going to go wrong.”

He admits he had never played on the “fat comic” card. In fact, his size had played very little part in his day-to-day life up to that point.

“Part of the show is about the effect weight loss has on your life and how people perceive you,” he says. “I’ve turned from one type of person to another. When you are heavy, people assume you are one type of person, it influences their thinking about you.

“I was a fat kid – it wasn’t middle-aged spread – I was fat as long as I can remember. Going into a non-fat life was an eye-opening experience.”

This Komedia show is set to combine the hour-long Edinburgh show with a 45-minute greatest hits set, drawing on songs from throughout his career.

Benn says he has never made a distinction between his stand-up and songs – the two have always been linked.

“In the Fringe show there are nine songs – it’s an even split between blether and songs,” he says.

“It never occurred to me not to come up with songs in my comedy. You bring whatever you can to the table and music was one of the things I could bring.

“Once I got on The Now Show, songwriting became a central part of what I did. I have to keep writing this stuff, so I might as well keep using it!

“You do get comics who play the guitar early on in their career but get very self-conscious about it and put the guitar away.

“I think it would be cheeky to go on stage and say, ‘I don’t do that any more.’”

  • Komedia, Gardner Street, Brighton, Saturday, March 9. Starts 7.30pm, £12/£10. Call 0845 2938480