Natalia Vodianova used to find modelling unfulfilling.

The Russian supermodel decided to cut back on modelling jobs in favour of charity work in 2004 when she realised they had no higher ''purpose'' and she was missing out on spending time with her three children.

She told The Telegraph newspaper: ''Things change. I stopped enjoying what I was doing. I started from nothing but I worked hard and it was great. I earned good money and I had wonderful things....

''I was surrounded by everything I ever wanted but then, one day, I started to wonder why I was leaving my husband and children to earn more money. Why? I saw no purpose in it, and I needed to see a higher purpose.''

Since taking a back seat from modelling, Natalia set up the Naked Heart Foundation to help underprivileged and disabled children in Russia, and the charity has become her main focus.

She said: ''I was very happy being a model and I still am, but the more I work with my charity the more I want to do. I have become pretty obsessed.''

However, the 31-year-old brunette worked incredibly hard to become one of the most recognisable faces in fashion and says she was driven by her need to feed her single mother and autistic half-sister Oksana back in Russia when she started out as model in Paris aged 17.

Natalia said: ''I was so hungry for it. I had no other choice. Other girls did. They had families, nice lives. I had nothing. I couldn't go back - there was nothing to go back to and I had promised my family... I needed to earn money, to send money home.''