"Food miles" entered the public conversation as a shorthand for the environmental cost of transporting food long distances. The concept is intuitive: food that travels fewer miles from farm to table requires less fuel and generates fewer transport emissions. That part is correct. But food miles alone do not tell you the full environmental story of any given food — and understanding the nuances makes for more grounded decision-making.
What food miles measure
Food miles measure the total distance food travels from its point of production to the point of consumption. They are most often discussed in the context of imported produce — strawberries in winter, avocados from Central America, grapes from Chile — but they apply to any food traveling through a supply chain.
The concept was popularised in the 1990s and has since become a common shorthand for sustainable food choices. If you buy a tomato grown ten miles away versus one shipped from across the country, the logic goes, your tomato has fewer food miles and therefore a smaller environmental footprint.
When food miles matter most
The transport footprint of food depends heavily on how it is transported. Sea freight, road freight, and air freight have very different emissions per kilogram per kilometre. A shipment travelling across an ocean by cargo ship has a much lower per-kilogram emissions rate than the same product shipped by plane.
This is where food miles become most significant. Air-freighted produce — typically highly perishable items like fresh asparagus, berries out of season, or certain fish — carries a carbon footprint that can be ten to fifty times higher per kilogram than sea or road freight. For air-freighted foods specifically, reducing food miles has a meaningful impact. Avoiding air-freighted produce is one of the higher-impact transport-related food choices a buyer can make.
For foods transported by road or sea, the food-miles calculation becomes less dominant compared to production emissions.
The production problem
Multiple life-cycle analyses of food systems have found that production — how food is grown — typically accounts for far more of its carbon and environmental footprint than transportation. A 2008 study published in Environmental Science and Technology, which remains one of the most-cited on this topic, found that transport represents roughly 11% of the average American food item's lifecycle emissions, while production accounts for around 83%.
This means that the food miles question, while real, is secondary to questions about how food was produced. A conventionally farmed product grown locally may still have a higher total footprint than an efficiently produced item imported from a region with ideal growing conditions. Beef raised locally with poor land management practices will have a higher carbon footprint than many imported plant foods, regardless of food miles.
The food miles frame is a useful starting point, but it should not be the only lens.
Where local buying and shorter food miles converge meaningfully
Despite the above caveats, there are genuine environmental benefits when shorter food miles align with other favourable factors. Local field-grown produce in season typically involves neither energy-intensive greenhouse production nor long-distance freight. When all of these conditions are met — regional origin, appropriate season, field production, road or short-haul transport — the food miles reduction is real and accompanies lower production emissions too.
This is the context in which buying locally tends to have the clearest environmental benefit: not because distance alone determines impact, but because local buying during the right season correlates with better outcomes across multiple environmental dimensions simultaneously.
Last-mile logistics
An often-overlooked part of the food miles conversation is last-mile logistics — the final transport from distribution centre or store to a consumer's home. A buyer who drives twenty miles to a farmers market and back may accumulate more transport emissions for that trip than the food itself generated in shipping.
This is one area where direct online ordering from local producers, with consolidated delivery routes, can be meaningfully more efficient than individual shopping trips. A single van delivering to ten homes in a neighbourhood generates far fewer per-order transport emissions than ten individual car trips to a market.
Why food miles still matter as a concept
Even with its limitations, the food miles concept is a useful prompt for thinking about supply chain structure. Very long supply chains involve more logistics infrastructure, more cold chain management, more handling transitions, and more opportunity for waste. Shorter chains are generally simpler, involve fewer intermediaries, and generate less incidental waste and inefficiency even beyond direct transport emissions.
There is also a resilience argument. Supply chains that span continents or multiple countries are more vulnerable to disruption — by fuel price spikes, weather events, political instability, or pandemic-related logistics failures. Shorter, regional supply chains are more resilient to those shocks, which has indirect environmental benefits through reduced emergency logistics and food security risks.
A grounded approach
For buyers who want their food choices to reflect genuine environmental concern, a reasonable framework involves paying attention to production method and food type first (what you eat generally matters more than where it comes from), then considering whether what you are buying involves air freight specifically, and then, within those constraints, preferring regional and seasonal options where available.
Buying from local producers is a good default for multiple reasons — lower likely transport emissions, reduced packaging, fresher product, support for regional food systems — even knowing that food miles alone do not tell the whole story.