What do I do in this situation??????

OK, so my parents are a little weird. Lately, they have been restricting my food diet a lot. They never let me eat until I am full anymore. Therefore, whenever my food is taken away from me, my stomach is still empty and I feel dissatisfied. Parents also don't allow me to snack in between the tiny meals I eat. I don't know why, because I am not at all big. I am 5 feet 0 and only 80 pounds! It's almost like they are just being mean cause one night when we went out to dinner they wouldn't let me order anything and they did. So that night, I never ate dinner. I was really upset by this. What should I do?