Picking up on the previous comments about the pressures put on young women to be accepted as catwalk models, I can say what you hear is usually true. The cotton wool, the coke and an apple a day etc.
When I was little, I used to dream of being Miss World and walking along the best catwalks in the world as I guess a lot of girls do. I was constantly being told I should be a model, so decided to try out for it after being spotted by a photographer who gave me a card.
Following a long period of being ripped off, abused verbally and physically, and starving myself half to death, I wasn't getting anywhere. That's how I fell into glamour modelling and it's a very slippery slope.
Although my waist was 23inchs, I had always had a large bust which wouldn't go regardless of how little I ate. This was why I couldn't fit in the sample sizes. However, I was perfect for lingerie, page 3 etc. I was smart enough to always take a male with me on shoots, but a number of girls didn't. Unfortunately, I can tell some horrific stories.
To cut an already long story short, I made a good living out of what I did, and live well now, but trust me, it is not an industry I would be happy having someone I loved working in unless they had the ability to learn quickly to be thick skinned.