Liposuction removes fat cells permanently. The fat cells that are removed by liposuction can never come back, however if the patient gains a significant amount of weight, then new fat cell can develop. With a small weight gain, existing fat cells simply get bigger by accumulating more fat within the existing cell.
However, with an increase of more than 10% of body weight one can expect new fat cell development in all areas of the body, including areas previously treated by liposuction. As an adult gains larger amounts of weight, increasing numbers of fat cells (lipocytes) are formed. Hence, it is important to note that patients must not gain further weight after liposuction.