When we long for food, we crave for the nutrients, the energy, the strength, the endurance, in short, the life food can give us. Craving for food is also longing for the experience of food: seeing it, touching it, smelling it, tasting it. When eating and sensorially experiencing food, we incorporate a part of the world around us. We thus confirm our dominance over the world.

Food for consciousness
When we bite into a piece of food, we don't generally do it in a spirit of humility. It's merely an act of self-asserting aggression, a necessity for survival, just as much as the newborn baby's determined yet unconscious hanging on to mother's breast and for dear life is an inborn behavior designed to make the earthly newcomer's first encounter with the hardship of the world as safe and as tolerable as possible. As the newborn baby experiences its mother's lukewarm and thick milk, it becomes for the first time conscious of food. And while the baby grows toward child- and adulthood the physical experience of food turns psychological, then mental, too.
The physical consciousness of food is the primary and primeval one. As we start liking and disliking food, as it begins to affect our emotions, the physical consciousness of food is superseded by a psychological one. All the while, we also learn to discriminate the various kinds of food. The more edible items we are able to recognize, the more we know about food and the chemistry and physiology of its digestion, the more our psychological consciousness of food turns into a mental one. This is when we start thinking about why we like certain food items more than others and about what constitutes the ideal food combination for our physical, psychological and mental well-being. We may even try and come to understand how exactly food affects our existential totality.
Life's immortality

This is of utmost importance as food is our permanent contact with the world. We depend on it for survival, as much as we depend on the world. Through food, with it, and for it, we manipulate, control, create and destroy our environment. When we eat plants, animals and the products thereof ( fruit, seeds, nuts, milk, eggs, etc.), we continue to be what we were as newborn babies: aggressive in the sense of asserting ourselves for survival purposes. If we don't kill and eat animals to survive, we can eat their eggs and milk or feed on plants only. If, furthermore, we don't want to use animal products or kill plants for food either, we will have to feed ourselves on plant products only. Yet, whatever we do, we in some way have to destroy life or potential life. This is so simply because life feeds on life. It is life's way to secure its immortality.

Eating is our attempt to secure our immortality, too. We, moreover, can decide about our nutritional behavior. Eating vegetarian is leaving animals the right to assert their will to life. Being vegan, on the other hand, is leaving them the possibility and the right to procreate (eggs) and to feed their off spring (milk). Some of us rely on fruit, seeds, nuts and the like for food only, because they try to avoid taking the life of plants. This makes it very difficult and mostly impossible not to interfere with potential life.
Whatever, the further we evolve along the line of non-interference with the various expressions of life's struggle for immortality and the less harm we do to animals and plants, the greater our humility and reverence for life. If a nutrition-based spirituality means anything, then this is what it is all about: a way of nourishing oneself that is aggressive as an act yet peaceful and altruistic in its intention.