The concept of food miles is part of a broader issue of sustainability which deals with a large range of list of environmental issues, including local food. The term was coined by Tim Lang (now Professor of Food Policy, City University, London) who says: "The point was to highlight the hidden ecological, social and economic consequences of food production to consumers in a simple way, one which had objective reality but also connotations." 
A DEFRA report in 2005 undertaken by researchers at AEA Technology Environment, entitled The Validity of Food Miles as an Indicator of Sustainable Development, included findings that "the direct environmental, social and economic costs of food transport are over £9 billion each year, and are dominated by congestion."
Recent findings indicate that it is not only how far the food has traveled but how it has traveled that is important to consider. The positive environmental effects of specialist organic farming may be offset by increased transportation, unless it is produced by local farms. But even then the logistics and effects on other local traffic may play a big role. Also, many trips by personal cars to shopping centers would have a negative environmental impact compared to a few truck loads to neighborhood stores that can be easily accessed by walking or cycling. A flavorer endeavors to eat food from within a "food shed" having a radius of 100 miles.
Business leaders have adopted food miles as a model for understanding inefficiency in a food supply chain. Wal-Mart, famously focused on efficiency, was an early adopter of food miles as a profit-maximizing strategy. More recently, Wal-Mart has embraced the environmental benefits of supply chain efficiency as well. In 2006, Wal-Mart, CEO, Lee Scott said, "The benefits of the strategy are undeniable, whether you look through the lens of greenhouse gas reduction or the lens of cost savings. What has become so obvious is that 'a green strategy' provides better value for our customers" . Wal-Mart has since made a series of environmental commitments that suggest the company is looking more holistically at supply chain sustainability, such as restricting seafood suppliers to fisheries independently certified as sustainable, a practice that may increase food miles. Still it is undeniable that Wal-Mart's strategy of using supply chains from as far away as China exorbitantly increases greenhouse emissions. They are often criticized for "green washing" and only adopting large-scale green tactics, which make them appear earth-friendly but actually have little positive environmental impact.
Critics of food miles point out that transport is only one component of the total environmental impact of food production and consumption. In fact, any environmental assessment of food that consumers buy needs to take into account how the food has been produced and what energy is used in its production. A recent DEFRA case study indicated that tomatoes grown in Spain and transported to the United Kingdom may have a lower carbon footprint in terms of energy efficiency than tomatoes grown in the United Kingdom, because of the energy needed to heat greenhouses in the UK .