I'm not sure it's at all that simple.
We know that if you do less activity, then there is less energy spent from ingested food. The excess must be excreted or stored - often both.
Since metabolism refers to all chemical processes involved in converting food to usable activity, if a slowdown occurs, then food is digested slower and less efficiently, usable energy is extracted less quickly, energy is expended less efficiently, and so on. I imagine that depending on where the efficiencies are comparitively lowest would control how a slower metabolims manifests. Getting fatter easier could be one result. Needing to eat more is another. Requiring more rest-room visits could be another.
Wade.
