So how does Katie look so good?

Talk about Mission Impossible... it has been a mere 17 days - count 'em - since Katie Holmes gave birth to daughter Suri, but Tom Cruise has not wasted any time in wheeling out his fiancée to help publicise his new movie.

And yes, it has to be admitted that she is looking pretty good. But the question celeb-watchers will no doubt be asking is: has she gone for a Gwynnie Girdle? For, let's face it, most new mothers would not feel brave enough to face the world's flashbulbs only a fortnight after giving birth.

We all know now how Gwyneth Paltrow does it. Following the birth of Moses - a brother for her daughter Apple - she has been using a postpregnancy girdle recommended by her London obstetrician, Dr Gowri Motha: or, to be strictly accurate, two.

What about Katie, though? In this picture she is looking remarkably trim. All the weight she put on during pregnancy seems to have disappeared - or has it?

Does that black dress hide rather more than it reveals? It is rather loose fitting, is it not? Could there possibly be a girdle under there?

Her presence at the screening certainly came as a surprise to the fans gathered at Grauman's Chinese Theatre. When a 2006 Bugatti Veyron rolled up to the red carpet, onlookers only expected Cruise to get out of the vehicle, the fastest road car on the market. But there were whoops and cheers as he walked round to the passenger side and opened the door to let out Holmes, 27.

If she has opted for a girdle, she would be reflecting current trends. Most of us probably thought the girdle was something our grandmothers wore, but according to a new report it is having something of a comeback.

A survey by Mintel says British women are spending almost £50 million a year on underwear to control or improve their figures, particularly after having children.

Even Agent Provocateur, better known for its flimsy, glamorous lingerie, includes a girdle or "post-natal knickers", in its new maternity collection and claims it is selling "really well".

Sales of Marks & Spencer's Magic firming range have doubled in the past year. "It is the Bridget Jones phenomenon," said a spokeswoman. "Women saw her in big knickers. And it's stars such as Trinny and Susannah coming out and saying, 'Big knickers rock'."