Hi Mike,
He only drinks organic herbal tea that is caffeine free...so no diuretic effect. I'm the one who should slow down on the caffeine ( one cup a day).
My background is in science (Bachelors of Science: Biology and a Masters in physiology of exercise) so yes, you are right about needing less energy when we don't exercise. I am sure his basal metabolic rate is not what it was when he was muscular...
(Thanks for the tip about the Blue Cactus Bar and Grill, I'm sure I'll need a margarita soon. It's snowing in Ottawa, not too cold though...
Take care
Gisele