Dr Helga Dittmar's research shows how Barbie's unrealistic body proportions can negatively influence young girls.

Sussex psychologist Dr Helga Dittmar joins shopping guru Mary Portas on Channel Four tonight (3 October) to look at the success and influence of the world’s most iconic fashion doll.

Barbie: The Most Famous Doll in the World (Channel 4, 9.15pm) charts the history of Mattel’s fabulously glamorous toy, who made her debut in 1959.

But while Mary meets experts, collectors and fans young and old to find out what has made Barbie a worldwide multi-billion dollar business, Helga will be talking about her research that has shown how the doll’s superskinny proportions can have a negative influence on young girls.

In 2006 a study led by Helga showed that, following exposure to images of Barbie, young girls express a desire to have thinner bodies and also experience lower body esteem.

Helga says: “I was delighted to be approached by the programme makers to talk about my research and to meet Mary, who was just impressive - engaged with kids' well-being, very knowledgeable, and the most skilled presenter I have met over the years.

“Of course young girls love dolls. But my research has continued to show the harmful consequences of exposure to dolls that have unrealistic body shapes. So, why do doll manufacturers not produce dolls with a healthy-sized and well-functioning body?"

Supporters present another side of Barbie. Over the years she has modelled the outfits of 150 careers, from police officer to pilot to President of the United States, and has arguably introduced young minds to the feminist movement.

Now, with a growing mix of amusement vying for children’s attention, the programme, made for Channel Four by Sundog Pictures, looks at Barbie’s future and asks if she fits into the 21st century’s expectations of womanhood.