oh, wait.. you went from 21.5 to 19 BMI?? Hon, it takes fat to make the twins grow.. well, not lots, but you have the body mass of runners, athletes.. they have very little fat on their frames and are as flat at you seem to think you are. That explains a lot.. as funny as it sounds.. have a few cheeseburgers (you know what I mean) to stop the "lean machine" you are building yourself to be.
"You cant make bricks without straw"