Health-conscious snackers are eating so many packets of the Japanese half-inch-thick puffed-rice cracker that Tesco estimates that 48,000 a week are being sold.
Troy Smith, managing director of London's hip health-food store Planet Organic, says British ricecake devotees are taking their cue from the US.
"The ricecake has been hugely popular in the States for many years," he says. "You can buy them on every street corner, not just in specialist health shops. Most American trends end up over here and the ricecake has definitely arrived."
Mr Smith's shop sells 400 packets a week, outstripping all crispbread sales. "Health-conscious and diet-aware shopping is really trendy right now," he says. "We are selling more ricecakes than we do, say, Ryvita, but then we like to think that our customers are at the forefront of body awareness."
Because ricecakes, as well as being kosher, contain no yeast or gluten, they can be eaten by people who have an allergic intolerance to bread and crispbread products.
Holland & Barrett, the health-food chain, says it sells thousands of packets each week. A spokesman, Phil Geary, said: "We've seen sales rocket in the past 12 months and we've now got around 10 varieties on sale. You could say ricecakes are the Ryvita of the 1990s."
With about 25 calories per cake, the compressed rice disc is also popular with weight-watching models. Madonna is said to breakfast on ricecakes thinly spread with soya margarine.
Kevin Thomas, managing director of Kallo, Britain's leading ricecake brand, says the company has doubled production in the past year. "We sell millions of packets a year and I've no doubt that ricecakes are suddenly trendy," he says. "Westarted making the ordinary round ricecake in 1984 and now have snack size, square ones and even yeast-coated ones."
Such is the potential for a ricecake war that Mr Thomas was cagey about the precise increase in his ricecake sales. "Put it this way - there are lots of competitors watching what we do, so I'm not going to give too many secrets away. How do I know that you're not a spy from one of our rivals?"
He added, seriously: "I will say that we have got other varieties in the pipeline to satisfy consumer demand."
The ricecake is currently available in salted, unsalted and sesame varieties, with, it is rumoured, sweetened, possibly chocolate, versions on the way.
Tesco and Sainsbury's, which both report an increase in sales during the past year, say the ricecake is making a significant impact on the crispbread market. And Waitrose's Wendy Harries-Jones says: "Ricecake sales are buoyant. They seem to be popular with people giving dinner parties."
Although the ricecake has made an impact on the British diet, however, it still has its detractors. A spokesperson from Ryvita accurately described eating them as like "chewing on ceiling tiles", while a regular ricecake eater tartly commented: "I eat them for health reasons not pleasure. Why else would I want to bite into a cushion?"