Haha.....muscle burns first. The human body wants to hold onto fat as a source of insulation......your body fat and your fat surrounding the organs.
This is the reason why you have to keep your protein higher when trying to burn fat.....to prevent muscle loss.
Essentially this question all depends on one diet.
no.youre too simplicistic, but your ignorance is forgiven, you dont know how things work.dont want to infrigne your freddom of speech but keep mouth shut on matters you dont know, in own best interest.
first burned , depending on where one is(my goodness this feels so pointless, when you have diet knowlege knuckledragger levels like bikibi slut around who will never listen).means, did he train last few days, what did he eat etc.
if he didnt train the day before and doesnt go training for those 5 days, and does a proper 2 days carbo loading and bit fats before this, the muscle isnt going anywhere.can easy fast for 5 days, as long he dont work out, the glycogen will be enough for that time.
you couldnt be more wrong, the body wastes muscle as very last resort, jesus christ, go read some studies if you refuse to believe me, whos done this for decades consistenlty

read a fucking book on human metabolism, dont be such a dumb arsed twaat.
you eat sugars, body gonna shift into carb burning mode.
you eat fats, the body will try to use that energy asap, but itll also store it very fast.
then comes glycogen, you realize what it takes to deplete of glycogen entirely?no you dont.,
then comes the fatburning mode, and depending on bodyfat levels and hormone levels muscle might get lost, a slight bit in 5days, no fucking arm will fall off.
this stuf deserves a phd title i dont even know why im adressing you with this.youre ok in all the rest,but shuuuut the fuck up about diet and metabolic processes.
it depens furthermore on the activity in those 5 days.is he gonna lay round or run amarathon every day?
even then, how much muscle will be gone in 5days?how much calories does a marathon run burn?
i rest my case.
junior, to be frank with you, you are volatile like a little girl with this, find something that you can consistenlty run, you are bit like johy falcon the fat swine who changes his diet every other day.
eating and diet is no magic, its rather soemthing like second nature to this sport.
this isnt a last resort drstic diet measuremnet for fat soccer moms to lose a lbs before they fly to holydays on mallorca,when they have 100lbs to lose in the first place.
in a way you got the same problem they have, not being consistent over enough time.you try to overdo things.