In Brazil, food functions as an excuse for people to gather and celebrate - even if there is no particular reason for a celebration. Families and friends enjoy having barbecues or, especially on Saturdays, our famous feijoada dish. It is a moment to nourish our souls besides our bodies. While cooking and eating, people talk, tell jokes, discuss their lives and opinions, etc. The meal serves as a means to get closer, or to maintain the intimacy. Brazilians are mostly outgoing and friendly, and sharing food is a way we have to strengthen our bonds.
Everyone has their own culture, so I am not sure about whether this answer would apply to everyone, since each culture would have a different example/answer.
Here is a possible example that you could use to form your own answer though:
In Japanese culture, food - especially traditional food, serves as a way to preserve and keep the culture and tradition. It can preserve and keep culture and tradition, as well as allow for it to be passed down from each generation (eg: through teaching each other how to cook a traditional dish, etc).
