The US 'size 0' . . . the equivalent of an Irish size 4 . . . requires a 23/24 inch waist and is sported by such super-skinny celebrities as Nicole Richie, Victoria Beckham, and Eva Longoria, many of whom are groomed by the same stylist, Rachel Zoe. Alarmingly, 'size 0' is quickly being usurped Stateside by the even tinier 'size 00'.

"Size 0 sounds sexless and I can't see how a normal woman would get down to that size, " top couturier Richard Lewis told the Sunday Tribune. "I hate American influences, and thank goodness I've never had to work with a model that skinny. I prefer my models curvy to cater for all clientele, and the smallest model I've ever used was a size eight [Irish]. I'm surprised women are going down to a size four . . . people are freaking about losing weight."

Lewis's comments come as Brown Thomas in Dublin prepares to stock the 'size O' of the American collection 'Theory' for the first time. Currently, the smallest size BTs offers in the Theory range is a US 'size 2' (Irish size 6) but customer demand for the 'size 0' has prompted it to bring in the smallest size from America, which it will put on the rails in two weeks' time.

"This is the first time really we've brought in a 'size 0' and I welcome it, " said Shelly Corkery, head of fashion direction for Brown Thomas. "We go by customer request so if they want it, we'll order it in. The demand for 'size 0' is only starting now and isn't in full swing yet but it's up and coming. There's a bigger demand for smaller sizes nowadays.

"Rachel Zoe is the queen of American stylists and is responsible for turning celebrities like Lindsay Lohan and Nicole Richie into global style icons. Although they may be 'size 0', I think women over here are more health conscious and are more interested in getting fit and toning up rather than dieting to be stick-thin.

People have to be careful because thin is not nice, and style is not about sizing but about the clothing, " said Corkery.

The Irish 'size 4' isn't stocked by most clothes shops here, with the exception of Topshop, which has a 'size 4' in its petite range for smaller-framed women. US collections such as Banana Republic, DKNY, Juicy Couture, and Gap don't stock their 'size 0' in Irish clothes shops, with many garments only starting at an Irish size 6, 8, or 10.

According to Arnotts spokeswoman Tania Meighan, this is because the bestselling sizes among Irish women are nowhere near a size 4.

"The bestselling sizes in Arnotts today with women are 10 and 12, " she said.

"We also do a good trade in 14 and 16. This demonstrates that we have a long way to go to reach the American 'size 0' and hopefully we won't reach that unhealthy look we see in magazines. It'll be a long time before size four becomes the norm here."

However, 'size 0' and even '00' are popular in the US, especially in Los Angeles, where pencil-like slenderness is required for late-teens to mid-twentysomethings, and also for women of a certain social or professional aspiration who are expected to be rail-thin.

Will & Grace star Debra Messing said recently in an interview with Harper's Bazaar magazine, "In New York, I'm a hottie. In LA, because I'm no longer a 'size 0', I've fallen out of favour." Gwen Stefani, Lara Flynn Boyle, Sharon Stone, Julianna Margulies and Heidi Klum have all made similar comments.

However, successful Irish stylist Catherine Condell believes people are not always influenced by the tiny sizes of trendy celebrities splashed on magazine covers, and says that, in Ireland, a 'size 0' is currently not in demand.

"People are not that easily led, " she said. "We all like to read and look at gossip magazines but it needs to be taken with a pinch of salt. Have a read of it with your cup of tea but then put it down and forget about it.

Magazines sensationalise skinniness a lot but it's not to be taken seriously. The fact that the average Irish woman is a healthy size 12 shows that we are not being led by celebrity or American sizes.

"Realistically, designers and stylists know what market they sell to, and are conscious that they're not catering for a handful of skinny girls that make it as celebrities, " said Condell. "So that's why 'size 0' is not popular here."