Food labels should include information on a product's environmental footprint, as well as nutritional information, according to a leading food expert.

Tim Lang of City University, London, called for a 'universal' food label to address consumer confusion caused by a proliferation of labels. This should include the amount of water used in an item's production and the number of 'food miles' it had travelled to reach shop shelves, he added.

"Whilst governments continue to let the market take its course, ill-informed consumer choices are contributing to massive crises in human health, food security and environmental degradation," Lang, who is a columnist for The Grocer, told the British Assocation science festival.

"Evidence from water use alone suggests that we need to think more about 'hidden' impacts. Each bean from Kenya has four litres of potable water embedded - this from a water-stressed country."

The news comes after shadow health secretary Andrew Lansley last week said a Conservative government would axe the Food Standards Agency's traffic lights system in favour of a GDA-based scheme.