I have been so hungry lately. I will eat a meal and then an hour later I will be hungry again. I seem to be always eating. I haven't been gaining drastic amount of weight, but I worried I will soon. Is this normal? I know I have a fast metabolism, but still I am concerned my body can keep up. If it is just growing, will I be able to stop when I am finished?
I assume you are somewhere in your middle teenage years. Yes, it is normal to experience an huge increase in appetite while you are developing. A typical male teenager will eat about 5,000 calories per day while the typical adult male will only eat 3,000 calories per day. This will continue for while until your later teenage years or your early twenties (that is, until a little bit past the time you reach stage five in your development).
If you can continue to eat only when your hungry and only enough to say you are satisfied when you leave the table, then you should do well even as you get older. Eating frequent small quantities is better than eating a whole day's worth of calories in one sitting. The problem many men have is that they eat large quantities all the time without thought because it never impacts their weight. Thus, they develop a habit that eventually catches up with them when they get older. They continue to eat large meals, but once growth stops they no longer need the large meals. The result is they begin putting on fat. But if your habit is to only eat enough to be satisfied, then you will adjust the amount you eat to the amount you need.
You should make sure that when you are hungry that you fill yourself with nutritious things. It is easy to grab junk food, but these foods are rarely what your body craves and they won't truly satisfy your appetite. So if you are hungry, a small cheeseburger might be better than a large fry. A granola bar may be better than a shake. An apple and a handful of peanuts is better than a bag of potato chips. It is not that you can't or shouldn't eat the other things, but try to limit them to only once in a while. Keep the type of food you eat varied.