As was pointed out on another board, we are too often guilty of comparing fish feeding to feeding ourselves, or cats or dogs. The problem here is that we, and cats and dogs, burn massive amounts of energy every minute of every day regulating our temperature. It takes a lot of calories to maintain a healthy body temp--for mammals. In fish, reptiles and amphibians, there is no energy spent keeping warm--they just work muscles to swim, and digest. This requires much, much less food to maintain.
I feed every other day. Fish that get too much food are prone to health problems, just like humans.