When i am natural, i burn fat best at about 1800-2000 calories. It can sometime be slow but if i go any lower i really start to lose muscle. I will be taking test e. That would raise your metabolism but by how much. I am also cycling clen so i would assume that would burn a lot more calories by itself. So if i was cutting on this cycle, how can i figure out how many calories i need in order to lose the most amount of fat without any muscle. I know that no one can really tell me the amount but a general rule maybe...im 21, 6', 215, 17% bodyfat