No, it isnt bro science. If u eat a bunch then go do cardio, you arent using fatty acids. Insulin in the blood dictates this. Yes, u burn energy. No, u dont use fatty acids. U cant. Insulin doesnt allow it.
So yes, fasted cardio or fasted training, or even fasted HIIT (which is a form of cardio) does work well. I apply it now actually and it works quite well. There are several impressive studies showing such results, which I may find the time to post here later.
Lets not get into a pissing match here, but just understand that I have researched well beyond the walls of bro science in the tune of 1000+ hours regarding metabolism and how the human hormones interact with food and training. I'm not ignorant. I have no agenda. I have nothing to prove or gain by helping this young man. I wouldnt tell him something that:
I wouldnt do myself
That doesnt work
Has no science to support it
If u can have the self discipline to become efficient at bulking and cutting, learning how to do it in a lean fashion and learning to retain muscle while cutting, it is far superior than getting fat then overtaxing urself with a 16 week cut, in which u stall out at week 8 and have to resort to severe calorie cutting and lose a great deal of that mass u gained leaving u worse off than if u'd just aim to pack on 2-3lbs at a time and cut a few lbs of mass at a time.
It may not sound appealing to u because u havent tried it, or because ur not good enough at either to do them clean and efficient, which is ok. Most arent.