Robert > So it seems to me that getting the diet right is only one piece of the larger puzzle.

Back to the disagree with you mode ;-)

For the overwhelming majority of people, diet is a huge piece of the puzzle.  Exercise, yes, is also important.  But all you need is about an hour a week of that.  Anything more you're doing for reasons other than fitness.  Not smoking is key -- as is stress relief -- is avoidance of too much caffiene.  But diet is THE most important item IMHO.

Jim