Over the past 16 years, the distance travelled by food between farm, warehouse and shop has increased by half - but the amount carried is no greater than in 1978.
The study, by the Sustainable Agriculture, Food and Environment (Safe) alliance, a coalition of voluntary groups, is the first to survey comprehensively the growth in national and global supply lines that mean British supermarkets routinely airfreight fruit and vegetables from across the world, even when the same products are produced at home.
On supermarket shelves last month, for instance, were apples from the United States, which had travelled 4,700 miles, onions from Australia and New Zealand (12,000 miles), carrots from South Africa (5,100 miles) and green beans from Kenya (3,600 miles).
Food imports by air more than doubled during the Eighties and are still rising rapidly - by 15 per cent in the first half of this year, for example. Hugh Raven, coordinator of Safe, said it was 'madness to fly food halfway round the world when UK growers are going out of business'.
The report argues that the growth in long-distance transport of food benefits the supermarket chains but increases pollution. It is also bad for consumers: food quickly loses its nutrient value but many of the techniques and chemicals used to preserve it over long distances carry serious health risks, the report says.
The Food Miles Report: The dangers of long-distance food transport. The Safe Alliance, 38 Ebury Street, London SW1 W0LU; pounds 25.Reuse content