[emma01]

If I was to tell you the definition - I would be pretty much compying from wikipedia, so I will just post you with a link to some pages you might find useful.

http://en.wikipedia.org/wiki/Anorexia_nervosa

http://www.adha.org/CE_courses/course8/table1.htm - that is the simplified version of the diagnostic criteria for anorexia.

If your friends are concerned, then you probably are showing signs of abnormal eating, while you may not be anorexic, you may still have disordered eating and this is still a huge problem. Don't feel embarrassed about this though - you should go and speak to someone, your school will have a guidance counsellor who will be more than happy to help you out!
Only you will know if your thoughts about food and yourself are not normal - and I think you know there is a problem or you would not have bothered to find this site and actually post!

I hope you can sort this out soon!