Why the hell can't i gain any weight?

I'm nearly 17, and i eat like a PIG every single day of my life, i must consume at least 7x as much as a normal person eats every day, and lately I've been wanting to get into shape, get a six pack and get some muscles, and as we all know you need fat to turn into muscle first, but i CANNOT gain any weight at all. Is it because my metabolism is near around 3x faster than a normal persons?

I also don't want to use any unnatural stuff to gain weight (Protein shakes, and creatine) Can anyone help me?

Thanks.

Eat more candy and fat! Do more wokouts! That might help.