Essentially, metabolism keeps us alive.  Metabolism is an exceptionally complex and ongoing dynamic balance of anabolism (building up new tissue) and catabolism (tearing down damaged tissue).  This requires turning genes on and off to maintain wellness.  The master regulator of this complex biochemical dance is the master regulator of metabolism, AMPK. 

AMPK is an energy sensor.  If incoming energy (i.e., calories) is high, AMPK is inhibited to allow the extra calories to be converted into new tissue or stored for later use (usually as fats).  The gene transcription factor mTOR is needed for new growth and repair of damaged tissue, and it is activated with excess calories, especially protein.  It is also activated by excess insulin (i.e., hyperinsulinemia) that occurs with insulin resistance.    On the other hand, if calories are restricted, AMPK is activated to metabolize stored fat to be converted into chemical energy as ATP and to recycle damaged tissue to provide new building blocks to maintain and repair damaged tissue.  It is the dynamic balance of AMPK to mTOR that determines wellness.