That depends on how much water you're willing to change. As long as your nitrates stay below about 20, your fish will show good growth. If you overfeed them and the water gets too loaded, they will grow less in spite of eating more.
But certain fish like plecos and some livebearers, the so called "fei feng" and more typically must eat every day to maintain good digestive health, so in most cases more is better barring water quality. But obesity will kill fish, so avoid stuffing them silly.