What do you mean where does it all go? It's eaten. Saiyans need far more nourishment than humans. And when you show up to a restaurant with one full-blooded Saiyan and two half-Saiyans, food tends to disappear.

Oh yes, I forgot to mention- I'm an alien. [He sort of spits out the word alien with a little disgust. He's not horribly fond of being considered one but the fact still remains no matter how he goes about it that he is one.]