On the chance that this is a serious question, here is a serious answer.
When you enter puberty, your body has alot of work to do, lots of growing and changing. Your metabolism will usually speed up, and you need more energy for your body to do its thing.
Usually teenage boys turn into eating machines at this time to fuel the changes.
There is a chance that you are just not consuming enough calories to fuel your body, meaning that you are losing weight.
It might be worth uping your food intake, particularly high protein things like meat, dairy and also try pasta.
Dont make the mistake of thinking that this means you should be eating lots of sweets and junk, that will just give you spots and greasy hair!