The reason my opinion is the way it is is because I recently rescued a 7 (estimate!) year old WC ball python. It's previous owner had him for 5 years and fed him one small rat once a month for all of those 5 years. When I recieved this BP, it was (weight wise) quite healthy. It could stand to bulk up a bit, but it wasn't thin. Now that he's with me, he eats 1 large rat every 5-7 days..because that's when he acts hungry. He has put on a significant amount of weight, but isn't obese..just nice and thick. He is 4 feet long, by the way. A small rat for a 4 ft long BP once a month? It seemed to do him fine! He was hungry, yes, but unhealthy? no.