Nothing is more personal than food. It forces us to make decisions every day that have real and immediate impact, which means learning about what we're eating and figuring out how to make good choices is essential. As environmental issues move to the forefront of public consciousness, the meaning of a good choice doesn't just have to do with a food pyramid or a nutrition label, but with knowing where your food came from, how it got to you, and who was involved in that process.
Food is one of the primary subjects with which we deal when talking about backstory, since it's one of the most accessible means of understanding the life of an item prior to its arrival in your hand. In many ways, food is also one of the best and easiest places to push for a change in that backstory, whether calling for different conditions for the producers, demanding a change in a product's contents, selecting a new source, or deciding to grow your own.
It's also becoming more common for schools to offer healthier food in the lunchroom and better education in the classroom (or the school garden), setting kids up at a young age to feel empowered with good knowledge enough to make good decisions as they grow older. Many of these educational programs, particularly in urban areas, work to establish urban-rural connections that support farmers and make city-dwellers more aware of and connected to the origins of their food.
In order for food to be sustainable, it must be grown, processed, sold and consumed in such a way that it doesn't deplete the earth's resources, create injustice, or cause harm. The more we know about the whole story of our food, the better able we are to judge whether it's good for the planet and good for us.