There's an interesting post by Gary Paul Nabhan, one of the earliest proponents of local eating, in the must-read blog EatLocalChallenge. He offers suggestions on how to define local and regional foods:
1. Local means from a farm, ranch or fishing boat that is locally-owned and operated, using the management skills and the labor of local community members. A farm that is owned all or in part by an extra-local corporation, and which uses migrant workers who live outside the community does not benefit its community economically or culturally as much as it should.
2. A regional food is one that has been tied to the traditions of a particular landscape or seascape and its cultures for decades if not for centuries. If the same mix of mesclun greens is grown in greenhouses across the country and sold in every farmers market from Maine to New Mexico, it is more like a franchised product (from a seed company) than it is a local or regional food. Yes it may be produced five miles from your home and thereby reduce food miles, but its seeds are not saved and adapted to local or regional conditions, they are bought from afar every year.
3. The miles a food travels (“food miles”) must be placed in the size and volume of the mode of transport, its source of fuel, and its frequency of travel. Using biodiesel in a larger truck may be more efficient, and leave less of a carbon footprint than using leaded gas in an old clunker. One in every five kilocalories in the American food production and delivery system now underwrites transportation, as well as packaging and cooling while in transit, so this will be an increasingly important issue to solve by using alternative fuels, cost-efficient volumes, and ensuring that vehicles holding their full capacity in both directions, perhaps by carrying compost back to farms where the vegetables originated.
4. On farm energy and water use matter. If a farm near Tucson Arizona is irrigated from a canal that transports Colorado River water hundreds of miles (and at high ecological cost to wild riverine species), or if it uses fossil groundwater set down during the Pleistocene pumped by fossil fuel set down in Iran during the Pennsylvanian era, what is to be gained by promoting its food?
5. Other on-farm inputs matter just as much. Where are the sources of hay for livestock, compost for garden crops or nitrogen for field crops? They should be locally if not regionally-sourced. Why call lamb locally-produced in Idaho when its flock has wintered part of the year in California and its hay comes in from southern Colorado?
6. Fair-trade with other cultures, localities and regions is fair game. Circumvent they globalized economy for the items you truly need from other regions by establishing fair-trade exchanges. It is not that we don’t care about farmers and ranchers elsewhere, we simply don’t wish to see middlemen gaining more of each consumer dollar than the producers do. Producers inevitably plow money back into their communities and lands, intermediaries seldom do.
7. Invest in the foods unique to your region that cannot or should not be grown anywhere else. The attached RAFT map (pdf) reminds us of ancient food traditions based on climate, soil and culture, involving both native and immigrant foods that have adapted and been integrated into particular places. Because the U.S. currently lacks the geographic indicators such as denominations of origin that reinforce the links between place, culture and genetics of a particular food, these place-based foods are truly threatened by globalization. Invest in them and their original stewards.