Don't worry about it. You probably eat too much protein anyway. Give it a few years and protein will be the enemy and everyone will be rediscovering carbs. Just eat good old fashioned food, a bit of everything, and what you like. Do you know anyone who lived to 100 that even knows what a "carb" is?
The "range" is merely established by convention. If your computer supports 100 distinct values then you could say those values represent the integers [0,100) or you could say they represent the even integers in [0,200). The range can be arbitrarily large, but the precision is fixed.
Arbitrary precision is the correct terminology. I can already represent any size integer I want on any computer. I could just declare that MAXINT represents Graham's number (for example). That doesn't mean that I can represent every integer between zero and Graham's number, though.