[paavoova]

As far as I understand, all excess amino acids (that is, not used for protein synthesis), are indiscriminately metabolized for energy, diet doesn't factor into it. Your body cannot readily store amino acids outside of those free floating in the bloodstream (although it can store them in the form of tissue to catabolize later). A quick search will tell you that 13 amino acids are exclusively glucogenic (as opposed to ketogenic). Given that metabolism occurs in the liver, and the liver has little use for immediate energy, little direct oxidation occurs, so probably the majority of amino acids are converted into glucose and transported elsewhere. This is the reason your urine is yellow, it's from the urea which contains dietary nitrogen waste from the constant metabolism of protein (carbohydrates/fats don't contain nitrogen).

Didn't bother with sources, so feel free to do your own research.