So to a side issue illustrating some of my issues with set point theory. One subject of the article went from over 300lbs to 140, yep. Using gastric bypass surgery.
In short, our set point, if we have only one as such, is the genetic set weight we are destined to be within the range of about 20 to 30 lbs or so either way.
My feeling is, we are looking at it from our obsession with every pound, induced by weight loss hysteria of weight loss diet fail.
What I suspect is that the above weight loss is in the overall scheme of eating and converting and use of energy, etc, that the body's metabolic processes go through over the years, that differential is tiny.
That's why I suspect that our set points are not specific enough to vary only by 20 30lbs, unless there is no pressure of forces on our individual systems of a weight adjusting kind.