As Americans head to the grill to celebrate July 4th, it's a perfect time to ponder another kind of freedom -- the gastronomic kind

On Saturday, barbecues across the United States will be fired up to celebrate Independence Day, a national holiday during which Americans will eat 150 million hot dogs, according to the National Hot Dog & Sausage Council, which notes that's "enough to stretch from D.C. to L.A. over five times."

Iowans in particular have a big appetite for pork. On March 1, 2008, according to the U.S. Census Bureau, the Hawkeye State had 17.6 million market hogs and pigs -- more than one-fourth the nation's total. Most of those piggies stayed home: About a quarter of Iowa's citizens ate hot dogs and pork sausages last July 4th.

But there is another celebration lurking, just outside the plates of over-antibioticized, factory-processed meat and GMO corn on the cob. It's Food Independence Day.

Coordinated by the nonprofit group Kitchen Gardeners International in partnership with the IATP Food and Society Fellows program and the Mother Nature Network, the sustainable, eco-friendly holiday calls upon Americans to declare their "food independence...by sourcing the ingredients for our holiday meals as locally, sustainably and deliciously as possible and let's ask our elected officials to do the same," according to their Web site.

"For too many in the US, the 'choices' will be Bud or Miller or an industrially-produced hotdog or an industrially-produced hamburger," writes Food Independence organizer Roger Doiron in a Kitchen Gardeners International article.

The Food Independence Day campaign comes on the heels of the June 12 U.S. theatrical release of Food, Inc., a new documentary by Robert Kenner that, according to the film's Web site, asks the question: "How much do we really know about the food we buy at our local supermarkets and serve to our families?"

The film exposes the harsh realities of the American food industry, such as widespread obesity, the development of new strains of harmful E. coli bacteria, cows living in their own waste before being led to slaughter, chickens that can't walk because their breasts have been artificially plumped and companies that value profit over consumer health and environmental protection.

The New York Times called it "one of the scariest movies of the year...an informative, often infuriating activist documentary about the big business of feeding or, more to the political point, force-feeding, Americans all the junk that multinational corporate money can buy. You'll shudder, shake and just possibly lose your genetically modified lunch."

Big agribusiness and giant factory farms are exposed in the film. These corporations rely on uneducated consumers, many of whom maintain extremely unhealthy diets in a broken system that is quite literally killing people. What many consumers don't realize is that their voice can be heard with their food choices.

The Fourth of July is all about the independence of the United States. But when it comes to its food industry and the eating habits of its citizens, the nation is stuck in a vicious cycle of co-dependency.

Hopefully this July 4th, Americans will think of a different kind of independence and heed the rallying cry of sustainable-food advocate Michael Pollan: "Vote with your fork."