I'm not hungry at mealtimes...?

I'm 16, about 5'3, and 130 pounds. I find myself just not hungry when dinner rolls around, I eat anyways (I eat lunch around 12, and dinner around 5) I should be eating around 2000-2500 calories of food, but I eat about 1700, aed find myself not hungry (but not full either) when lunch and dinner comes around. What can I do to feel hungry at mealtimes, and eat the healthy amount of calories? Or should I just eat when I'm hungry, and eat just till I'm full, instead of trying to get the right amount of calories?