Pregnant women require a completely varied diet to ensure that they tackle the issue of obesity during pregnancy, an expert has claimed.

The concept of mothers simply increasing the amount of food intake when pregnant has also been rubbished, as a moderated amount of foods containing fibre, vitamins and vegetables is far more important, according to the chief executive of Baby Lifeline.

Judy Ledger, chief executive of Baby Lifeline, said: "You shouldn't be dieting, but you should be eating sensibly. I think people go from one extreme to another, and people basically need to be sensible. You don't have to be fanatical."

Ms Ledger added that mothers who suffer from obesity during pregnancy can cause a range of problems, including diabetes and anaesthesia.

Meanwhile, the Royal College of Midwives and Netmums recently released information suggesting that 70 per cent of mothers "ate for two" when pregnant, while nine per cent ate "substantially more" than their usual servings.