Food miles explained: do they really matter?

Distance is easy to picture and easy to criticise. But lifecycle analyses of food consistently show that what you eat, and how much of it you waste, usually matters far more than the number of kilometres it travelled to reach your plate.

What food miles are and why they caught on

The term 'food miles' was coined in the early 1990s to describe the distance food travels from where it is produced to where it is consumed. The idea was simple and intuitive: food that travels further must use more fuel and therefore must have a bigger environmental footprint. Buying local, by this logic, was automatically the greener choice.

The concept spread quickly because it gave shoppers a clear, actionable rule: look for the origin label and choose the one from closer to home. It also aligned with other values — supporting local farmers and economies, getting fresher produce, maintaining a connection to seasonal rhythms. These are all genuinely good things, which helped the idea stick.

The problem is that food miles tell only part of the story — and for most foods, not even the most important part. Subsequent lifecycle research began to unpick the full picture, and the findings complicated the simple 'closer is better' narrative.

Why food miles alone are misleading

When researchers trace all the greenhouse-gas emissions associated with a food item — from the farm through to the table — transport consistently turns out to be a relatively small fraction of the total for the majority of foods. The much bigger shares come from what happens during production: farming practices, the type of food being grown, the animals involved, the fertilisers used and the land required.

Consider a few reasons why distance can be a poor proxy for environmental impact:

• Transport mode matters enormously. Sea freight is dramatically more efficient per tonne-kilometre than road transport, which is itself far more efficient than air freight. A food item shipped across an ocean by sea may arrive with lower transport emissions than one driven fifty miles in a small van.
• Load and efficiency vary. A full container ship moving tonnes of produce is very different from a half-empty lorry making short rural deliveries.
• Production method dominates. For most foods — especially animal products — the emissions generated during farming (methane from livestock, nitrous oxide from soils, feed production) dwarf the contribution from transport. Moving a beef steak from one country to another adds relatively little to an already high-emission product.
• You cannot tell from a distance whether something was grown efficiently or wastefully. A tomato grown in a nearby heated greenhouse in winter might have higher overall emissions than one grown outdoors in a sunny climate and shipped by road.

This does not mean transport emissions are zero or unimportant — just that they are often not the deciding factor when comparing similar foods.

When food miles genuinely do matter

Food miles are not irrelevant — they just matter most in specific circumstances. Two in particular stand out:

Air-freighted produce. Air freight emits far more greenhouse gas per tonne-kilometre than road or sea transport. While the vast majority of food is transported by ship or road, a small subset of highly perishable goods with short shelf lives — certain fresh berries, some exotic tropical fruits, specific cuts of fresh fish or seafood — are flown to market because they cannot survive the time a sea journey would take. For these products, transport genuinely forms a significant part of the total footprint in a way that it does not for sea-shipped goods. Unfortunately, produce is rarely labelled to indicate whether it was air-freighted, which makes it hard to identify at the shelf. Items that seem unusually out of season or exotic and arrive in pristine condition from a distant continent may give a clue.

Out-of-season hothouse produce. This is not strictly about miles, but it connects: when a food is grown in a region where the climate is wrong for it — salad leaves in a northern winter, tomatoes in a cold climate all year round — it may be produced in a heated and lit greenhouse. The energy used to maintain a growing environment artificially can add significantly to the footprint of that food, regardless of whether it is grown locally or shipped from a warm country where it grows outdoors in season.

The nuance: local hothouse vs in-season import

This leads to one of the more counterintuitive findings in food sustainability: a locally produced food is not automatically lower-carbon than an imported one.

Take tomatoes as a commonly used example. In a cold-climate country, growing tomatoes locally in winter requires artificial heat and lighting. Depending on the energy source, this can result in a higher footprint per kilogram than tomatoes grown in a warm country where they ripen outdoors in natural sunshine, even accounting for the road transport to bring them north.

The relevant variables are:

• Whether the food is in its natural growing season.
• Whether it was grown in a climate that suits it, or in an artificially heated environment.
• What energy source powers any controlled environment.
• How it was transported (by sea or road is generally fine; by air is high-impact).

None of this is easy to read from a supermarket label. But the practical takeaway is clear: eating produce that is naturally in season — whether it comes from nearby or from a region where that food grows well — tends to be a better choice than insisting on local produce that required energy-intensive artificial growing conditions.

The real benefits of local and seasonal

Acknowledging the limits of food miles as a rule does not mean abandoning local and seasonal food. There are genuine and meaningful reasons to value it:

• Freshness and quality. Food picked closer to its destination typically reaches you sooner, which usually means better flavour and texture — particularly for fragile fruits and salad leaves.
• Less packaging. Local food sold through farmers' markets, box schemes or independent shops often comes with less plastic packaging than supermarket equivalents.
• Supporting local growers and economies. Buying from local farms and food businesses keeps money circulating locally and can help sustain smaller, more diverse farms. This has social and economic value that emissions accounting alone does not capture.
• Connection and transparency. Buying directly from or near the source can give you a clearer picture of how your food is produced — and that transparency has its own value.
• Seasonal variety. Eating with the seasons naturally rotates what is on your plate across the year, which can contribute to dietary variety and tends to coincide with when produce is cheapest.

For practical guidance on making the most of local food, see our guide to shopping local for food, and for eating with the seasons, our seasonal eating guide has region-by-region help.

The bigger levers: diet and waste

If food miles are a limited tool, what should you focus on instead? The evidence consistently points to two areas where individual choices make the most difference:

What you eat. The type of food on your plate — especially whether it involves ruminant animals like cattle and sheep — has a much larger effect on the total emissions associated with your diet than where it came from. Shifting some meals away from beef and lamb toward chicken, fish, eggs, pulses, or plant-based options reduces your diet's footprint more than most transport-related choices. Our explainer on the carbon footprint of food covers this in detail.

How much you waste. Food that is wasted carries all the emissions from its production, processing and transport — and then produces methane in landfill. Wasting less is one of the most impactful things a household can do, and it saves money directly and immediately. Planning meals, storing food well, and cooking with leftovers are among the simplest and most effective changes.

Keeping these priorities in order helps avoid a common pitfall: feeling virtuous about choosing a local imported-style product while missing the bigger picture of overall diet and waste habits.

Sensible choices checklist

• Prioritise eating produce that is naturally in season where you live or in a climate where it grows well.
• Be cautious about highly perishable, exotic produce that seems unlikely to have arrived by sea — it may be air-freighted.
• Shop local where it adds freshness, reduces packaging, or supports producers you value — but don't assume it always means lower emissions.
• Focus the bulk of your effort on what you eat — particularly reducing how often you eat beef and lamb.
• Waste less: plan meals, freeze what you will not use, and cook with leftovers.
• Enjoy imported staples (rice, pasta, olive oil, pulses, spices) without guilt — sea-shipped goods have low transport emissions per serving.
• When buying perishables, consider whether they are in or out of season and where they are likely to have come from.