I've seen the show on DHC a few times and I'm confused too. My belly button is at the same level as the top of my hip bone. Gravity? So I have a 41.25 inch waist? Not that I'm anywhere near where I need to be, and I'm sure I'm still in denial about my size, but my stomach simply doesn't protrude as far as some of the people I've seen on the show with the same size waist. So, I dunno. Then again it seems like 50% of my weight is in my mid section. And My mom as the nerve to complain (to me of all people!!) how she can squeeze 2 inches of fat on her stomach.
For those wanting to know how often? I don't know what the book says but for me 38lbs = -5 inches from that belly button area. I measure it every 10 lbs or so. Even then the reduction never seems to be much.