In other words, if your maintenance calorie level is 2400 and you want to maintain and you respond best on a 40-30-30 balance of macros, you can get all of your calories at McDonalds if that's what you want to do, keeping your balance and calorie level where you need it.
It just may be a bit harder to do at McDonalds and to keep the fat levels where you personally might need them, the menu choices may not be any tastier than doing it yourself.