LongevitybroTX said:
(I dont truly believe in a 'set point', but I've gained and lost enough weight over the years that I sure do understand how difficult maintenance can be).
There are many issues with "set point" theory. I think that issue that has troubled me the most is the directional asymmetry. Specifically, that it's rather difficult to reduce a person's set point, but returning to a higher previous set point seems pretty easy.
Rather than think of a set point, I've come to apprectiate the concept of defended fat mass. Specifically, that your body has a specific amount of fat it has decided it needs to survive, and it will fight hard to keep that amount. When fat stores drop below that level, your brain responds by making you hungrier, slowing your metabolism, and reducing your energy (all at the same time) until the fat comes back.
The problem is that this defended level can creep upward over time, but almost never resets downward on its own. So the body that once defended 180 pounds of fat mass will, after years of obesity, defend 240 pounds just as fiercely, and after weight loss, will work relentlessly to get back to 240, not 180.
Set point theory seems to suggest that if we stay at a lower weight long enough or adjust our behaviors well enough, that our bodies will reset to a lower set point. I haven't seen any data to suggest that anything less than bariatric surgery will have a lasting effect on a person's set point, if one even exists.
I would say that bariatric surgery does appear to have adjusted my "set point" if I had one. Prior to surgury in 2003, I weighed 455 pounds. Since then, I've gained and lost weight, but never weighed more than 335. Not that that is good, but it's better than 455.