Lol the amount of flaming over poor casein
It's very simple. Being on a calorie deficit = catabolic state. Overnight fast = catabolic state. There's no store of amino acids like there are for fats and carbohydrates. Your amino acid stockpile is your muscles, that's the reserve. So if you're cutting weight, you're already prone to breaking down your muscle so you want to make sure to eat some sort of dairy-derived protein before bed so it takes the amino acids from that. Cottage cheese, Icelandic yogurt, Greek yogurt, proteinated milk like fairlite or w/e it's called, etc. RIP lactose intolerant sherbros, sucks to suck. If you're maintaining or bulking it's not that important, I think you can mostly ignore it.