Research by the Bread for Life campaign shows that two thirds of young women are unhappy about their weight and 20% diet all or most of the time.

Ms van Outen is heading the Bread for Life campaign, which is backed by Elite Premier model agency, to encourage young women to adopt a more healthy attitude to food.

She said: "Most young girls look to me as a role model and think I crash diet to keep a slim figure. That's not true. I am lucky to have a slim build and always eat properly."

She said she often ate take-away food and admitted that her boyfriend, Jay Kay of pop band Jamiroquai, had made her fish and chips on their first date.

Guilt

Bread for Life interviewed 901 young women between the ages of 18 and 24.

It shows 60% of women feel guilty about eating. Twenty-nine per cent resort to exercise after eating something they think they should not have.

Ten per cent starve themselves and 7% binge on more food.

Just 26% said they ate a balanced diet with 41% saying they were constantly trying to keep their weight down.

The Bread for Life campaign, launched in 1992 by the Flour Advisory Bureau, fears unhealthy attitudes to food could lead to eating disorders.

Five per cent of teenage girls in the UK develop anorexia and 20% of these die in the 20 years after the onset of the disease.

Bread for Life is also launching a series of free leaflets on healthy eating.

They include three flexible eating regimes, designed for women whose lives vary from sedentary to very active.

Looking your best

The Elite model agency, whose models include Claudia Schiffer and Cindy Crawford, said it backed the call for women to develop healthy eating patterns.

"Models need to look their best," said a spokeswoman. This included having healthy, shiny hair, bright eyes and good skin.

Denise van Outen's boyfriend Jay Kay cooked her fish and chips on their first date

Starving and binging would not keep them looking their best, she said.

"There is no way they would be able to get up at 6am and stand on a freezing beach if they were not eating well," she said.

She denied that Elite's involvement in the campaign was designed to counter media criticism that models are too thin and encourage young girls to diet excessively.

"Models have been used as a scapegoat in the past, but not Elite" she said.

"We have always been responsible and no-one could say Claudia Schiffer and Cindy Crawford are too thin, but we have to respond to demand. Otherwise we will not get jobs."