if its serious enough they are bound by law to tell your parents about it as it is potentially harming to your health
its not to get you into trouble its for your health and safety eating disorders can be dangerous if left uncheck i wont tell you how because i wouldnt want to scare you into doing it simply out of fear but trust me telling someone and getting help is the best thing you can possibly do for yourself
talk to you..don't be afraid of them taking extreme action.There are support groups and indiviual therapy that is very affective ,also if you are interested there are medications to help subside your "issue".Mental evaluation would be the first step ,I assume.
discuss the problem, try to work on solutions with you (hopefully you are willing to work on getting better).. in more serious cases the therapist might try to get you in a program specifically designed for dealing with eating disorders..
Offer you a sandwich.