21/02/2012 07:07 GMT | Updated 21/04/2012 06:12 BST

Miss Representation: You Can't be What You Can't See

From music videos to magazines, billboards to the catwalk - the media and its treatment of women is rarely held up to such close scrutiny as it is in Miss Representation, Jennifer Siebel Newsom's powerful documentary.

The film is a vivid and often moving exploration of how media portrayals of women have led to their underrepresentation in positions of power and influence in the United States. While the American-made film focusses on the situation in that country, the issues it raises will resonate with British women and anyone who consumes mass media this side of the Atlantic.

Growing up in a society immersed in media of many forms it becomes harder and harder to tell where the line blurs between images that are real and those that have been enhanced though plastic surgery or airbrushing.

Girlguiding UK's recent Girls' Attitudes Survey found that, of the 1,200 girls aged seven to 21 who took part, 47% feel the pressure to look good is the most negative part of being a girl. Clearly girls feel compelled to live up to what are often the impossible ideals of beauty seen in glossy magazines and on billboards.

With my fellow Advocates I delivered a petition to Prime Minister David Cameron calling for more honesty about the use of airbrushing in advertising which was signed by more than 25,000 people, demonstrating how public opinion is hardening against the practice.

Miss Representation asks a series of important questions: Why are we creating a world where a woman is seen as nothing more than her body? Why are we living in a world where girls are pressured into focusing on their looks and not what they've achieved? Is our media turning us into "a nation of teenage boys", as one contributor suggests?

It's shocking to hear Afghanistan has a greater percentage of women in its parliament than the USA, and the documentary brings to light the causes and effects of the leadership gap. As the film argues, a key reason for the underrepresentation of women in leadership positions is the media's misrepresentation of them. In a society captivated by reality TV, gossip columns and paparazzi photographs, is it any wonder that women are being reduced to little more than sex objects?

Accomplished and successful women are no more immune from this than anyone else, as one particularly shocking section of the film - a montage of television clips of Hillary Clinton and Sarah Palin being referred to in extremely sexist and derogatory terms during the 2008 Democratic nomination and subsequent presidential election - clearly showed.

As Lynne Featherstone MP, who sits on the APPG on Body Image alongside representatives from Girlguiding UK, quite rightly stated after the screening: "Your value is way above what you look like". But the truth of the matter is there's a glaring lack of positive female role models in society, which is both reflected in and perpetuated by popular media.

Through Guiding, girls learn about strong and successful women who can inspire them to challenge themselves in all areas of life. But in wider society, many aren't aware there are these women who they can look up to. The media has a huge role to play in ensuring that this doesn't remain the case.

Women may have equal rights and opportunities protected by law, but thanks to the media the gender disparity between men and women is more apparent than ever. Miss Representation serves as a spark for debate in the hope that we can create a world where the media values and champions accomplished women. After all, you can't be what you can't see.