What's hot on the catwalk has changed dramatically over the years. Here's Betty Grable in 1944, complete with curves!
This is Marilyn Monroe in 1954. Millions of women tried to look like her and copy her womanly shape.
In the 1960s fashion changed and models became less curvy. This model's real name was Lesley Hornby, but because of her shape she was known as Twiggy.
Claudia Schiffer hit the catwalks in the 1980s, when the look was all about big hair and glamour. Many models also brought out exercise videos at this time.
Kate Moss is probably the most famous UK model. Here she is in 1999 - with a quite boyish look that's become more and more fashionable.
But some bucked the trend. This is Sophie Dahl - granddaughter of author Roald Dahl - who had some success in the 90s. But then she became a lot thinner!
One of today's most famous and well-paid models is Brazilian Gisele Bundchen. She was apparently spotted by a scout eating a burger at a fast food restaurant!