I feed my fish live feeders... I have 2 oscars and 1 jack dempsey. I don't get mine from anywhere but the local fish store and then quarantine them for 2 weeks before to make sure they are healthy. After they eat the feeders, they usually won't eat for a few days. I wait for them to do the "feed me" dance at the top of the tank before I even attempt to feed them.
One time mine did over eat and he laid at the bottom for days pooping. Then he let out a nice big poop and was back to normal.
These guys will eat and eat until there is no more food. Like the other guys said, we have to control how much they eat.
Post your levels though.... we like specific numbers so we can help you better.
Brooksie