i dont think most animals fast intentionally. i say most cause bears and other animals hibernate but that's not the same thing as not eating regularly because you have to hunt for your food. When i learned that it was safe to leave your fish un feed while you were on vacation because in the natural environment they could go weeks without eating i realized maybe i shouldnt feed my fish every day 3 times a day. It has improved the water quality for my tank since there's less waste for the filter to deal with and also there are scientific studies that a low calorie diet for a variety of animals including humans can lead to longer life spans. it's very tempting to feed your fish as much as it can eat and to see it grow so large, i mean this forum is MFK. but i think we do this at the stake of our pet's longevity. Its truely to each their own and it's up to everyone to find the balance that's right for them.