Food waste is a big deal in America. As grocery stores stock their shelves with holiday goodies, preparing for the rush of feasting consumers, much of what retailers sell won’t end up in people’s stomachs -- it’ll end up in the trash.

Each year, 1.3 billion tons of food is wasted around the world, much of it in rich countries where grocery stores throw out imperfect products and consumers toss uneaten food. Since the 1970′s, America has seen a 50 percent jump in the amount of food wasted, according to the National Resources Defense Council. Consumers play a major role, tossing away roughly 250 pounds of food per person every year. But supermarkets play an even bigger role, discarding 10 percent of America’s total food supply at the retail level.

All that uneaten food accounts for nearly one quarter of U.S. methane emissions, a greenhouse gas that traps 25 times more heat than CO2.

This problem has spawned a range of reports and education programs designed to get Americans and retailers to waste less. But there’s another option that often gets overlooked: why don’t we just eat more of the food that grocery stores are throwing in the dumpster? That cuts back on both consumer and retailer waste.

There are already plenty of people, often called “freegans,” who do this.The term freegan, which blends together “free” and “vegan,” is finally becoming more widely known in mainstream culture -- even if it is a practice that has been around for as long as food itself.

Part money-saving opportunity, part political-statement, and part environmentalism, the modern freeganism movement -- also known simply as dumpster diving -- has spawned a culture of its own.

A new short documentary film, called “Spoils: Extraordinary Harvest,” intimately explores this culture. The film follows groups of dumpster divers in New York City and paints a portrait of the people who dig for wasted food.

The film because doesn’t try to pretentiously puff up the importance of dumpster diving, it simply provides a raw look at how it’s done. Freegans are in a way, the urban equivalent to our romanticized notion of indigenous cultures that “live off the land” and take only what they need.

Something to think about as you sit down for your Thanksgiving feast.