Gemma Arterton cries when she gets heartfelt letters from fans.

The 27-year-old actress feels incredibly proud when she reads messages from teenagers and women who say they are inspired by her curvier figure, and she strives to be a positive role model for girls who struggle with their body image.

Speaking on British TV show 'Lorraine', Gemma said: ''I'm really passionate about it (being a role model) because women are wonderful and we come in all shapes and sizes and that's OK.

''I think we're so inundated by images of what people think is beautiful, but if we start putting things out there that aren't [perfect], I think its good for girls to see things differently.

''I've had the most wonderful letters - it makes me cry weekly - from girls saying, 'I used to have an eating disorder and I look at you and you inspire me to be normal [sized].'

''It's like, 'Oh my gosh!' It's so important.''

Gemma's latest role in fantasy thriller 'Byzantium' sees her play a bloodsucking vampire called Clara, who raises daughter Eleanor (Saoirse Ronan) alone.

The screen beauty was inspired by her own mother Sally-Anne - who was raised her and her sister Hannah as a single parent - and she says her performance is a ''love letter'' to her mum.

She said: ''It was a love letter to my mother. This film is about women and the complexity of being female ... Clara's not a hero by any stretch, she's also a prostitute and she kills people, but more in the resilience and the protection of your child and how much you would do just to make your child's life easy. It's about unconditional love.''