Most aquarium hobbyists are guilty of over feeding. If I have one fish in a tank I feed the amount of food as big as the fishes eye twice a day.
Keep in mind fish eat until the food is gone. They are hard wired to do this as a survival mechanism.
In a complete ecosystem something in the food chain eats that pellet. I highly doubt that it goes to waste unless you are grossly over feeding. This is unlikely because feed is expensive.
