I am not trying to lose fat and gain muscle at the same time. I have done a search and read a bunch of threads, but I'm still not sure on how this is possible. I'm only interested in learning, and not putting anything into practice; I accept fat gain.
Anyway, your body needs a certain amount of calories per day, for important functions and energy and things. If you workout, and only eat this many calories, your body won't have any extra calories to build muscle with because it doesn't want to take away from more important functions, so in order to gain muscle you must eat more than this amount of calories. Your body won't burn fat if you are eating enough, so you need to eat less. To build muscle, eat more. To burn fat, eat less. One can't eat more and less at the same time, so one can't build muscle and burn fat at the same time.
Ok, I have read that, contrary to my "argument," it is possible, so what about my understanding is incorrect, or what is missing, or is it just way to simple? Sorry, if this question annoys anyone.