As i already due to her divine protection, she possesses immunities that make her lose things:
"The Divine Blessing of the Hero gave all kinds of resistances. Among them was complete immunity to sleep. Ruti no longer needed sleep. She would never feel drowsy. She would maintain a perfect condition 24 hours a day without needing to sleep at all.
According to the mantra she secretly held, normal resistance and complete immunity were completely different. Normal resistance was to become stronger against something but complete immunity was to lose something. In this case, what she lost was the ability to sleep.
Furthermore, she had complete immunity to the berserk status even if she was angry so it was just to the extent of minor waves of emotion.
Due to her complete immunity to confusion, Ruti calmly understood his words. Due to her complete immunity to despair, Ruti was not shaken by those words."
Ruti's body's condition is always at it's peak, she never feels hungry, tired or sick etc, cause she lacks the ability to do so:
"I possess all kinds of resistance in my body. No matter if it is extreme cold or intense heat, my body temperature will never change. That applies to the warmth from the bath as well, I can only gain information that this is hot water."
"I don't fall sick and I don't tire. My body condition is always at its peak."
"It is the same for meals too. I can never feel hungry. Neither do I need water. I can taste food but my body does not require nutrients"