The spiritual reason behind uttering God’s name on our food before eating it is given in 16:114. This is to constantly remember and be appreciative of God’s blessings on us: So eat from what God has provided for you, it is lawful and good and give thanks for God’s blessings, if you do worship Him. 16:114. This act of appreciation for God’s blessings would not belong to us if we rely on someone else, in a slaughter house, uttering God’s name.