Oh!¡! Alex not needing to eat or breathe, does that mean he has possibility of being immortal? I mean immortal in terms of aging?
The way I figure it, Byte only provides Alex's body with energy in place of his natural functions.
The human body only needs to eat and breathe because of cellular respiration (energy production). Eating allows glucose to enter the system, which is the molecule that holds everything we need to produce ATP, the energy our bodies use, but it includes an excess of carbon. This excess carbon needs to be removed to prevent poisoning, so the Krebs cycle uses it, combined with the oxygen we get from breathing, to produce CO2 that we can easily get rid of.
Bypassing ATP production and outright immortality would not be caused by the same thing, especially considering Alex gets super hungry the one instance that Byte's not in his mind.