Absolutely flabulous at the club night where big is beautiful

There's a fat lady singing in the corner, but the show's only just begun. Dukes, near Liverpool Street in central London, is playing host to the capital's latest clubbing phenomenon: Big Girls Paradise.

Women of a certain bulk – and their surprisingly numerous admirers – have squeezed into the spacious basement bar for this, Britain's only club night for the size 16-pluses.

With recent statistics showing that one in five Britons are now clinically obese, it shouldn't really come as a surprise that Big Girls Paradise has proved such a hit. Now more than ever, the fleshy pound is worth its weight in gold. And that's serious money.

Tomorrow, 20-stone Pop Idol finalist Rik Waller releases his début single, "I Will Always Love You", while manufacturers and employers are watching profits swell in this burgeoning market.

Demand for Big Girls Paradise, which began with a group of friends meeting in a London bar in 1996, is now so great that the organiser, Linda Koch, is doubling its frequency to every fortnight and adding a night at another venue. Offers are flooding in, including one from a record company eager to make an official CD, and enquiries from French and German promoters keen to try the concept. Big Girls Paradise is already involved in a lucrative promotion with London radio station Kiss FM, and Ms Koch, 40, has high hopes for the brand.

"Eventually, we want to have a Big Girls Paradise in every major UK city," she said. "We're already getting people coming here from up North, down South and all over."

On Saturday, Ms Koch, will see her business enter its latest phase, when Big Girls' Paradise is launched at its new venue: No 3 Green Street, in Mayfair. With up to 350 regulars at the £12.50-a-head Dukes events, she is confident that her latest venture will prove just as successful.

"Big Girls Paradise has really taken off in the last couple of months," said Ms Koch, herself a size 24. "The whole thing started out as a hobby really, and then it just got really big – it's serious business now."

Half the reason for the success of Big Girls Paradise has been the men who frequent it. Calling themselves "FAs" (Fat Admirers) or "CCs" (Chubby Chasers), they match the women for numbers, if not size. One FA, Richard Beatty, 37, a science editor from west London, could definitely be described as slim.

"I've been coming to these events regularly for two years," he said. "It's the only specialist venue if your tastes run to larger women – and mine do."

Lisa Fleming, a business development manager from Luton, whose age, 28, matches her dress size, was celebrating her recent divorce. "Since I've been coming to these events my confidence has gone through the roof," she said. "I can come here and feel comfortable wearing whatever I like. Before I found this night I wouldn't even show my arms, but once I'd been here a few times I started coming in a PVC mini-dress."

The current Miss Big Girls Paradise, 31-year old "domestic goddess" Bronwen from Reading, was enjoying the evening with one of her friends. "It's just about complete acceptance," she said. "I'm letting my hair down tonight – we're having a large one."

Additional reporting by Robin Smith.