BBL works via fat transfer. The fat that survives the process of grafting becomes a natural part of you behaving as it would if it had never be harvested. Thus it is susceptible to weight gain and loss as is all the fat in your body.There is no solid data for predicting the behavior of a particular population of fat cells. Patients will often lament that weight loss often precipitates changes in areas they had not anticipated or hoped for, i.e. "my breasts shrink and my tummy remains the same!"When an individual gains or loses weight, the fat cells swell or shrink. Thus after BBL, the donor sites will have a smaller population of cells which can swell or shrink. This does not mean you cannot gain weight in these ares, however, the logical conclusion is that weight gain is less likely. The same logic applies for grafted areas (buttock) which now have a larger population of fat cells (assuming graft take/vaibility). Some believe that the grafted fat cells will behave exactly as they did before (if you always gained weight in your abdomen and never lost then it would stand to reason that those fat cells from the abdomen would behave similarly in the buttock). Anecdotally, I have seen fluctuations of both types in patients. This is difficult to predict with any degree of certainty. As always, discuss your concerns with your board certified plastic surgeon.
