Goldfish can and often will eat bread, but it may cause stomach problems. Commercial flake food made for goldfish provides a safe, balanced diet. Supplement flake food with live food and safe household foods for best results.
Purchase live food from a reputable pet store. Brine shrimp and earthworms are the safest kinds, as they do not transmit goldfish diseases. Tubifex worms, mosquito larvae, daphnia and bloodworms can be used if they are freeze-dried. Do not harvest live food from ponds or streams, as it may be infected. Safe household foods for goldfish include seafood, beans, peas, spinach, and lettuce, as well as cooked broccoli and cauliflower. Dice or shred all household foods before feeding them to goldfish.