> can't really count calories Sure it can. Your body knows whether it's putting glucose on the shelf or taking glucose off the shelf, because it's the one doin

> can't really count calories Sure it can. Your body knows whether it's putting glucose on the shelf or taking glucose off the shelf, because it's the one doing it. It knows how many reserves it's keeping, because it's the one keeping the reserves. See: leptin, but in general the problem of reliable energy storage/retrieval is a strict superset of the energy accounting problem and yet our bodies accomplish the storage/retrieval problem with many 9s of reliability.