A commonly highlighted cause of eating disorders is the proliferation of modern media and the celebrity culture which is obsessed with staying thin and looking 'good'. This may partially explain why so many young girls get the disease as they are at the age where they idolize people very easily and are very impressionable and can be easily led with what they read or see.
However, another source of 'inspiration' for sufferers of anorexia and other associated disorders are pro-anorexia sites or 'pro-ana' as they are known in modern parlance. These sites actually endorse the disease in a way that does not befit it, glamorizing it in a way that is not correct and is essentially flawed. They regularly post quotes and motivational posters encouraging people to keep going and to starve them because it will all be worth it in the end. The phrase 'no pain, no gain' aptly sums up their ethos and style of thinking.
The fact is that these websites are abhorrent to people getting better. They blatantly encourage anorexia and say how good it is despite considerable evidence to the contrary. People with anorexia are much more likely to get depressed and be socially isolated than those who do not have the terrible disease. Furthermore, as a lot of the people who suffer from anorexia are in their teens or at an early developmental stage, the disease can harm their progress and even prevent puberty from taking place and stop girls from having their period, which is not something they should have to go through.