Food contains energy and requires energy to produce, process, and transport. When we waste food we waste the energy that was used to 
produce, process and transport this food.
In July 2010, the American Chemical Society (ACS) published a study entitled “”Wasted Food, Wasted Energy: The Embedded Energy in Food Waste in the United States” authored by Michael Webber and Amanda Cuéllar from the University of Texas Center for International Energy and Environmental Policy.
This research calculates the amount of energy used to produce food from agriculture, through transportation, processing, retailing, and finally for preparation and consumption. This data was then combined with food loss factors from the USDA to calculate the energy lost in wasted food.
Between 8 and 16 percent of energy consumption in the United States went toward food production in 2007. The U.S. Department of Agriculture estimates that in 2007, 27 percent of the food produced in the US was wasted. Michael Webber and Amanda Cuéllar estimated that this represents about 2030 trillion BTU of energy in 2007, or the equivalent of about 350 million barrels of oil, which is about 2 percent of annual energy consumption in the U.S..
The authors of the article noted that “The wasted energy calculated here is a conservative estimate both because the food waste data are incomplete and outdated and the energy consumption data for food service and sales are incomplete.”. In other words, the real energy loss from waste food is likely worse that the estimates.
I know I waste food. How do I know this? Because I love food and I tend to buy more food than I consume. So the question I ask is: how do you know how much food to buy for a week in your household? When do you know you bought too much food?
