As most TreeHuggers know, eating local and organic benefits the environment in myriad ways, but perhaps the greenest thing you can eat is your greens. That's because animal products are particularly energy-intensive and contribute heavily to greenhouse gasses. One study found the production of meat and diary contribute far more to greenhouse gasses in the U.S. than the emissions associated with shipping these products around the country.

From freegans to vegans, this glossary of terms shows the many ways people approach eating sustainably.