Just as natural food feeds the natural body, so too does spiritual food feed the spiritual body. And since our spiritual body is the expression of what we love, then spiritual food is what feeds our state of love: It is the desire for good, the delight of being good, the understanding of what it is to be good and the knowledge of all that's true and leads to what is good. So when food is talked about in the Bible, that's what it means, and the huge variety of forms food can take represent the huge variety of good we can seek in life and the huge variety of thought we can have leading to it.

(References: Arcana Coelestia 680, 1695, 4792, 5147, 5293, 5576, 9003)