Adipose tissue depots in rats can restore fat pads through de novo creation of new fat cells.

“Jules and Irv were extirpating adipose tissue depots from rats and looking to see what happened and one of the things that they were struck by is that when they took a fat pad out if they waited long enough and just let the animal eat whatever wanted to eat it would eat its way back up to restoring that fat pad through de novo creation of more fat cells you leave the capsule of the Depot there and it is able to generate new fat cells and they fill up and they don't fill up to three times the size that they were before they go right back to the appropriate size for that Depot”