To our ancestors, food was the spiritual essence of all that sustains life. Food was a bite-sized mystery that contained everything unexplained. So when our ancient ancestors made food sacrifices to the gods, to give thanks and respect for the mystery, perhaps this was one way they could entertain control over the unknown. The food leftover from the sacrifice was then considered blessed by the Divine and consuming it allowed humans to join in the immortality of the spirit realm.
Offering food to the gods was one way our ancestors coped with a terrifying world filled with the rawness of birth, death, disease, and famine. More importantly, by skillful cooking of the sacrifice, the offering became something more. For in creating something new -- transforming grapes into wine, grain into a loaves of bread, and animals into roasted meat -- humans interacted with the creative nature of the Divine.
Today there are still many folk cultures that partake in ritual food offerings and re-inscribe this sacred relationship between humans and the Divine. However, modern society seems to have lost touch with this humble act of giving a portion over to something bigger as a way of recognizing our deeper connection to the world.
Here's a simple Zen Buddhist practice that I think could be easily adapted to our modern sensibilities and made a part of our lifestyles:
Zen Buddhists make food offerings to "hungry ghosts" (symbols of craving) by passing a bowl around the table before the beginning of a meal. Each guest takes a small piece of his or her own food, gently touches it to their forehead, and places it in the offering bowl. The offering bowl is then set upon the alter. This food is later placed outside for birds and other wildlife to consume.
"Hungry ghosts" represent our greed and keep us stuck in a state of dissatisfaction because we believe if we don't fulfill these cravings we will never be happy. By giving away things that we crave, cling to, lust after, and thirst for in this world, we untie ourselves from the cycle of suffering and free up our energy for more creative ways of relating to other people and our world.