Is it normal for a 13year old to have such a big appetite?

On weekends I CAN'T stop eating!During the week,I only get to have a nice dinner but during the whole day I have snacks,cause the school canteen is DISGUSTING but then again I have dinner at home and get a second serving often.On weekends I really crave everything and like now I just ate a bowl of bran flakes,bread with peanut er and a chocolate-banana toasted sandwich and I'm still craving donuts!I'm not overweight(since during the week I don't eat much)and don't exercise LOADS...But is this normal?Is it possible my body's making me do this cause I'm having a growth spurt?I NEVER was like this before,please help!