If they didn't consume food to maintain their energy, they would need to rely on crystal cores, which were easier to gather in the zombie-infested world. These cores could sustain their energy for a longer period. However, consuming crystal cores had its drawbacks. As they used the cores to maintain their energy, their experience levels would also increase. This meant they might level up sooner, but without ensuring their foundations were steady and well-built, they risked advancing with a weak foundation.