Simply considering whether dinner was grown organically was no longer enough. Concerned parents, greenmarket shoppers and the rest of the food elite began calculating ''food miles.''

Food miles are determined by estimating the distance food has traveled to get to your plate. This generates more decision making: Are organic bananas really worth the cost of the jet fuel that carried them from Peru? Does an apple grown a few hundred miles away taste better than one grown 2,000 miles away? Is it better to support the local garlic farmer or the one in China?
—Kim Severson, "Food miles," The New York Times, December 24, 2006

Buying direct means producers get a fair price, with no middlemen adding big margins along the distribution chain. Nor has local food been shipped in from the other side of the country or the other side of the world, so the smaller number of "food miles" makes local food greener, too. Local food thus appeals in different ways to environmentalists, national farm lobbies and anti-corporate activists, as well as consumers who want to know more about where their food comes from.

Obviously it makes sense to choose a product that has been grown locally over an identical product shipped in from afar. But such direct comparisons are rare. And it turns out that the apparently straightforward approach of minimising the "food miles" associated with your weekly groceries does not, in fact, always result in the smallest possible environmental impact.

The term "food mile" is itself misleading, as a report published by DEFRA, Britain's environment and farming ministry, pointed out last year. A mile travelled by a large truck full of groceries is not the same as a mile travelled by a sport-utility vehicle carrying a bag of salad. Instead, says Paul Watkiss, one of the authors of the DEFRA report, it is more helpful to think about food-vehicle miles (ie, the number of miles travelled by vehicles carrying food) and food-tonne miles (which take the tonnage being carried into account).
—"Voting with your trolley," The Economist, December 9, 2006

Food miles are the distance food has travelled from its point of origin to you. In America, retail experts calculate that the average distance for any one item of food is around 1,100 miles. The contents of the average European shopping trolley travel 2,200 miles.
—Joanna Blythman, "Eat local and sever the food chains," The Independent, October 23, 1993