This
new study (via
NY Times) shows that within a year of liposuction, women regained all the weight and fat cells, but distributed elsewhere, since liposuction destroys the substrate under the skin on which fat cells grow.
Background knowledge:
fat cells produce hormones that affect hunger and metabolism (
resisitin,
adiponectin, and
leptin). A depleted fat cell “wants” to be filled. Excessively fat people often end up with diabetes and heart failure. They also really experience more physical hunger.
I have 70% belief in the following: if you overfill your fat cells, then the total number of fat cells increases (more or less permanently; they are replaced one for one as they die off). If you boost your peak number of fat cells, you will always have that peak number when you lose weight; they’ll just be emptier and causing you more hunger.
Tendencies to “put on weight” first in one location or another are at least partly due to the larger number of fat cells there.
A new theory proposed by the study authors (I don’t believe the evidence proves it yet): the body has some homeostasis in terms of the number of fat cells - if you destroy fat cells, it will add more (other than you’d expect from overeating so that existing fat cells are full). If this is true, they should be able to find something produced by each fat cell that doesn’t depend on its fullness (as well as the mechanism regulating fat cells birth as a function of that signal). I think this because if the same intensity of hormonal signaling can be caused e.g. by 2 full fat cells as 1 empty one then the liposucked women would be able to avoid growth of new fat cells by leaving those cells empty (which would require a change in their diet). In other words, I’m not sure how the authors ruled out the obvious explanation that the previously fat women continued overeating after the liposuction.
It is interesting at least, to know for sure that there’s not much obstacle to putting on a ton of fat anywhere and everywhere - that it’s probably not much harder to add 30lbs of fat to just the upper body (assuming full-lower-body-liposuction) than it is to add 30lbs distributed evenly (no liposuction).
