What food miles actually mean, and why the number on the label isn’t the whole story

Food miles are a tempting idea because they are simple. One number, easy to picture, and it seems to settle the argument. The trouble is that distance is only one part of what it costs the world to put something on your plate, and on its own it can point you in the wrong direction.

What the number does tell you

For anything flown, distance matters enormously. Air freight is in a different league from every other way of moving food, and the short-dated, delicate things are the ones most likely to arrive that way. If you want one rule of thumb that genuinely works, it is this: avoid air-freighted food. The label will not always say, but very short shelf life combined with a long journey is the signal.

Distance also stands in for freshness, and freshness is worth having for its own sake. Sweetcorn starts turning its sugars to starch the moment it is cut. Leaves wilt. A short journey is usually a fresher thing, and a fresher thing lasts longer in your kitchen.

What it leaves out

How the food was grown usually matters more than how far it travelled. A tomato ripened outdoors in a warm country and shipped by sea can carry a smaller footprint than one grown in a heated greenhouse down the road in February. Heating glass through a British winter is expensive in every sense.

The last mile counts too, and it is the part nobody measures. A lorry carrying twenty tonnes shares its journey between a great many items. One car driving six miles to collect one box does not. Collection points, village drops and combined deliveries do more for the arithmetic than the origin label ever will.

The part that is not about carbon

There is a second reason to shop close to home, and it has nothing to do with emissions. Money spent with a producer ten miles away behaves differently from money spent with a distant company. It is more likely to be spent again nearby. That is a reason in its own right, and it does not need the carbon argument to stand up.

A sensible way to shop

Buy what is in season where you live, because it will not have needed heat or a long journey. Avoid anything air-freighted. Group your collections rather than making a special trip for each. Waste less, which is the single largest saving available to most households.

If you want to see how this works out for a particular basket, our foodprint page at /foodprint walks through it, and the seasonal produce calendar at /resources/uk-seasonal-produce-calendar shows what is growing near you right now.