Fasted vs Fed Training for Fat Loss
This systemic review does not support a distinct advantage to fasted training vs fed training for fat loss or positive changes in body composition. Performing exercise in the fasted state did not promote weight loss or changes in lean/fat mass. There was also no detrimental effect found on body mass and body composition when utilizing this practice (i.e. there is no need for strict pre or intra-workout nutrition when training after an overnight fast).
In a fed state, the body has an increased thermic effect from food. In a fasted state, the body uses more endogenous fuels. This results in a net wash and explains why being fasted does not increase fat loss.