Alffe, my doc said its not reversible (unless its just what they call the "onset" of diabetes)... however, it IS controllable. The goal is go to change bad diet and exercise (or lack of) habits. That, in time, can keep sugar levels down ... and sounds exactly what your son in law has done. Weight gain is definitely not a good thing ... it what we all know... its what most of us struggle with as we get older.
Last night I was gifted a tin of home-made cookies... damn!
Re: David... I'm sure happy to see photos of his grandson on Facebook - what a doll-boy!!