It would seem to me, on the topic of set points, that the data is incomplete. Did they do studies on the fat cells of people that have maintained a substantial weight loss over time? Or are there just too few ... I kept waiting to hear studies about the "starvation mode" of formerly fat people's bodies years into the future. If your set point can go up and up (did nature really intend my co-worker to live with 450 pounds?) over time than can it come down too?
Like a few others have said, I found this book to be very disheartening.