Dear diary, why does my bum look so big after reading chick lit?

Self-scrutinising fictional heroines like Bridget Jones could be bad for your health, a new study has warned.

Research by Virginia Tech found that reading so-called “chick lit” books in which the protagonist worried about her weight made women uncomfortable about their own body image.

It looked at “the effect of protagonist body weight and body esteem on female readers’ body esteem” and concluded that “scholars and health officials should be concerned about the effect chick lit novels might have on women’s body image”.

The report’s authors took passages from two chick lit novels in which the protagonists have “healthy body weight” but “low self-esteem”. They then adapted the text from chapters of Emily Giffin’s Something Borrowed and Laura Jensen Walker’s Dreaming in Black and White into nine different versions in which the heroine’s self-body image was distorted. One variation read “I’m 5’4”, 140lb, and a size six”, and another, “I’m 5’4”, 105lb, and a size zero”.

The pages were then distributed to 159 students who were asked to note how they rated their own sexual attractiveness and body parts while reading each passage. Participants said they felt “significantly” less sexually attractive when they reading about a slim character, and significantly more concerned about their own weight when reading about a protagonist with low body esteem.

Melissa Kaminski, co-author of the report, entitled Does this book make me look fat?, who is a self-confessed chick lit fan, said she was compelled to launch the study after noticing that “body image research frequently looked at how visual images of thin women negatively affected women’s body esteem, [but] no research had examined how textual representations of body esteem and body weight affected female readers’ body esteem”.

The study is the latest evidence suggesting that self-esteem in the UK has taken a knock in recent years. Last year, a parliamentary inquiry found girls as young as five worried about how they looked.

The inquiry claimed half of Britons, male and female, had problems relating to their own body image, with the pressure to achieve an unrealistic “body ideal” now an underlying cause of serious health and relationship problems.