Functionally speaking, the primordial pouch serves another practical purpose: It allows the stomach to expand and swell with food. In wild cats, this allows them to consume a large meal while the getting is good. In domestic cats, this also allows them to consume a large meal while the getting is good, but you should be feeding your cat regularly enough that he doesn't need to gorge himself in one sitting. Incidentally, a 1997 study from Cornell University found that about 25 percent of cats in a veterinary survey were heavy or obese. Granted, the study was limited in scope, but it also pointed out the health risks of cat obesity, which include disease and death. Knowing about your cat's primordial pouch can help you tell whether he's overweight or not. A view from above affords a good gauge. Consult your vet if you're concerned.