In Christianity, fasting is not a stand-alone discipline: it is done in the context of prayer and alms-giving; in other words, it is outwardly directed as a way to deepen our relationship with God and neighbor.
An incarcerated friend tells me that he always looks forward to Ramadan (he is not a Muslim) because the Muslim inmates with whom he lives, who fast from food and water in all the daylight hours of Ramadan, receive a meal after sundown -- and most of them share the meal with the other inmates who ate normally all day long. I'm not prepared to draw any profound conclusions from that, except to say that God is good and so are God's people.