That's not called stability its called 'causality'. The body is a bio-chemical-mechanical machine. Changes over short periods of time are small enough to give a

That's not called stability its called 'causality'. The body is a bio-chemical-mechanical machine. Changes over short periods of time are small enough to give a perception of noticeable normal. But small changes are happening nevertheless. You get fat one more morsel of food, and one less body movement at a time. You lose weight the same way. One less morsel of food, and one more body movement at a time.