Feeding discus is sometimes a challenge. They have no unique nutritional requirements; they can be raised on just about any high-protein fish food. However, discus are often extremely cautious about new foods; it is not unusual for them to go for weeks without food before accepting a new type of food. (Therefore, when purchasing discus it is a good idea to ask what they are being fed.) After starving for a month discus will almost always accept a new food, but this may stunt the growth of younger fish.
It is not advisable to use the starving method for weening discus off of one food for another. Instead, mix the new food with the discus' preferred food. Over time, the discus will begin to accept the new food, and the old can be removed.
Beef heart is often fed to discus in order to promote good colouration and quick growth. Pork Heart has also been used to achieve a similar effect. However, concern over the long-term consequences of feeding discus a diet high in mammalian protein has prompted some hobbyists to switch their discus to a diet of krill, a shrimp-like crustacean.