The post-baby slimline rush

Doctors today warned mothers against the risks of dieting straight after giving birth.

Nearly half of mothers admit their main concern once the baby has arrived is to return quickly to their pre-pregnancy shape like famous mothers such as Liz Hurley, Catherine Zeta-Jones and Victoria Beckham.

However, experts today warned they could be risking their own health and their baby's by dieting so soon after birth. Consultant obstetrician Dr David Williams, of the Chelsea and Westminster Hospital, said: "The metabolism of women is changed dramatically during pregnancy, and it takes about a month to get back to normal. I would also advise any women to delay dieting until they have finished breastfeeding. On average, women tend to retain around 1kg after their pregnancy, although skin colour comes into it - black mothers seem to retain more weight."

A third of women blame society in general for pressuring them into regaining their figure as soon as possible. However, 85 per cent said public figures who made getting back into shape look easy were sending out the wrong message.

Miss Hurley embarked on a punishing diet and exercise regime to lose 53lb within 12 weeks of giving birth to Damian two years ago. Madonna attributed her rapid weight loss after the birth of Rocco to yoga. But experts warn mothers to have more realistic expectations.

Consultant obstetrician Dr Yehudi Gordon said: "Celebrity mums have a vested interest in getting back to shape because their public image is all important.

"But what new mothers must realise is that these women have taken time off to spend each day actively pursuing the result they want with the help of a team of experts, from nannies to personal trainers and dietitians."

Davina McCall, who shed weight more gradually after the birth of her children, was voted the most admired mother in the Pregnancy Pressure study from Norwich Union Healthcare. But a fifth said they were not impressed by anyone.

On the positive side, almost a quarter said the best thing about being pregnant was they could eat what they liked.

However, 13 per cent said the worst part was feeling fat and one in five feared they would never regain their pre-birth shape. Victoria Beckham sparked concerns for her health after her dramatic weight loss after the birth of Brooklyn, while Catherine Zeta-Jones reportedly lost four stones in 12 weeks after giving birth to Dylan.

With increasing numbers of famous mothers opting for scheduled births, half of those questioned-thought women should have the right to choose a Caesarean. Pain prevention and fitting the birth into a busy schedule were cited as the main reasons.

Most agreed those who did not have medical reasons for a Caesarean should pay for it, and just over a quarter would feel a failure if they did not give birth naturally.