Steve, you have just said, but worded much, much better, what I have spent the last year saying to every friend, family member and co-workers who keeps telling me they are on a
diet and how much weight they are losing through their "all I've had today is a carrot and a Lean Cusine" approach. I don't know how 1200 & 1500
calories became magical "one-size-fits-all no- matter-what-your-starting-weight" numbers, but I know from previous personal experience and the experiences of those around me that what you've said is dead spot on.