Katie Holmes with her Hermes bag

You'll need it to pay the osteopath and chiropractor's bills when your back goes.

Lugging around the giant bags that are in fashion at the moment can damage your spine, health experts say.

Women risk causing permanent damage by carrying overstuffed bags on one shoulder or in the crook of their arm.

Even carrying a bag in your hand, like actress Katie Holmes, with her ￡4,000 Hermes HAC tote, risks putting too much strain on one side of the body.

It is thought the average woman carries around 5.2lb in her handbag - twice as much as her mother used to.

Osteopath and acupuncturist Garry Trainer said he has noticed more women coming to his clinic with back strain.

"If a heavy bag is carried constantly on the same shoulder then it can compress the muscles on one side while stretching the muscles on the other," he said.

"Ideally weight should be carried across both shoulders close to the body.

"People do carry the kitchen sink in their bags and they should try and cut down what they carry around."

The trend for big bags is said to have taken off with U.S. stylist Rachel Zoe who thought they had the effect of making the carrier look petite in comparison.

Although the bags themselves are hardly lightweight, it is what is inside that really weighs women down.