Pope Shenouda III
Virtues which are intermingled, are gained through fasting
Fasting helps one stay up late because of the lightness of one's body. Staying up late leads to reading and prayer. Spiritual reading also helps one to pray. Spiritual work as a whole makes a spiritual person sit up late. Reading is a source of contemplation. Contemplation strengthens prayer which is also a source of contemplation.
Fasting is associated with prostration, which leads to humility and a contrite heart. A subdued body through fasting also leads to a subduing of the soul.