@KatawaGrey Got it. The very basics are Protein is broken down into amino acids and used by the muscles and other systems. Any extra that is not being stored or actively used turns to fat. Carbs are stored as glycogen in the body. Carbs are used for energy, and the nervous system uses carbs quite a bit, some other systems also. When runners “hit the wall” that means they have depleted their glycogen. When you eat carbs, and the glycogen fills up to capacity, any extra that can’t be stored or is not being actively used goes to fat storage. And, fat goes to fat.
Basically what this means is no matter what you eat, if you eat too much of it, the extra calories will go to fat.
Now, if you don’t eat any carbs for instance, and you get depleted in glycogen, the body can pull from fat storage and utilize these calories to keep the body functioning, but it is much more difficult for your system, and not ideal.