I ask a friend of mine about how to know when a metbolism is fast or slow and this was his answer: He said that a way to know that, if you eat a pretty big meal, and 30 minutes later you are hungry again that means ur metabo. is fast. Is that true? That happens to me and I don't really get fat easily since I am an athlete, (play soccer). Anyways, if that is not true, can someone explain how to know if it is fast or slow. Also, if I eat before bed, will the food digest correctly? does the metabolism function the same as when u r awake? Thanks.