i have an eating problem that's a bit strange.?

You have undoubtedly had your growth spurt and you have probably reached your peak height already. Girls usually stop growing at 15 and in most cases any further growth from 15-21 is insignificant.

With a fast metabolism it is unlikely that you will gain any weight so are likely to be slim for ever.

Well of course like you said it is cravings. So it could just be that you want the food. Cravings also come from periods so it could be that( I don't know if you are a boy or girl) instead of the fact that your body needs it. Although at 15 it could definitely be a growth spurt, and if it is don't worry about how tall you are. Everyone is beautiful in their own way. Growth spurts do have some negative side affects such as stretch marks, achey bones and joints, moodiness, slight crampy feelings, and headaches. Stretch marks are usually permanent, and very common when having a growth spurt, but the other ones are short term and go away after the spurt. Also most people don't eat properly and certain foods make you hungrier sooner, and sometimes almost right away. Drink more water and try to eat healthy. Eating healthy will make you feel so much better during cravings. Hope this helps!

I doubt it will affect anything besides your height or weight. You could gain some weight and stay the same height. There is no way of knowing exactly how much your height will change in comparison to your weight.

When you turn 15, you turn into a massive idiot, and can't eat properly.

Happens to 50% of girls.