More energy is wasted in the perfectly edible food discarded by people in the US each year than is available in oil and gas reserves off the nation’s coastlines.

Recent estimates suggest that 16 per cent of the energy consumed in the US is used to produce food. Yet at least 25 per cent of food is wasted each year. Michael Webber and Amanda Cuellar at the Center for International Energy and Environmental Policy at the University of Texas at Austin calculate that this is the equivalent of about 2150 trillion kilojoules lost each year.

That’s more than could be gained from many popular strategies to improve energy efficiency. It is also more than projections for how much energy the US could produce by making ethanol biofuel from grains.

Dairy foods and vegetables are the greatest culprits, with around 466 and 403 trillion kilojoules lost as waste each year, respectively (Environmental Science and Technology, DOI: 10.1021/es100310d).

The numbers are likely to be conservative, the team says, as they are based on food-waste figures from the US Department of Agriculture from 1995 – the latest available. Since then food prices have dropped and waste is likely to have increased. What’s more, the figures do not […]