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.

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

5293. 'And let them gather all the food' means all things that have a useful purpose. This is clear from the meaning of 'gathering' as drawing together and preserving; and from the meaning of 'food' as things which have a useful purpose. In the internal sense 'food' means, strictly speaking, those things which nourish a person's soul, that is, which nourish him when his bodily life is ended. For when this is ended his soul or spirit is living, and he no longer needs material food as he did in the world; but he does need spiritual food, which consists in everything that has a useful purpose and everything leading to this. That which leads to what has a useful purpose is knowing what goodness and truth are; and that which has such a purpose is the desire to realize these in actions. These are the things with which angels are nourished and which are therefore called spiritual and celestial foods. A person's mind - the place within him where his will and understanding, that is, his intentions or ends in view, reside - is nourished by no other kind of food, even while he lives in the body. Material food does not extend as far as that; it extends only to his bodily parts, which are sustained by that material food to the end that the mind may be sustained by food for the mind while the body is sustained by food for the body, that is, to the end that there may be a healthy mind in a healthy body.

[2] The reason 'food' in the spiritual sense means everything that has a useful purpose is that a person's entire knowledge, his entire understanding and wisdom, and so his entire will must have a useful purpose as its end in view. Consequently as is the nature of the purpose he has in view, so is the nature of his life. The truth that 'food' in the spiritual sense means everything with a useful purpose is evident from the following words spoken by the Lord,

Jesus said to the disciples, I have food to eat of which you do not know. The disciples said to one another, Has anyone brought Him anything to eat? Jesus said to them, My food is to do the will of Him who sent Me, and to accomplish His work. John 4:32-34.

And elsewhere,

Do not labour for the food which perishes, but for the food which endures to eternal life, which the Son of Man will give you. On Him the Father - God - has set His seal. John 6:27.