Energy use in the U.S. food system.

Energy is an important input in growing, processing, packaging, distributing, storing, preparing, serving, and disposing of food. Analysis using the two most recent U.S. benchmark input-output accounts and a national energy data system shows that in the United States, use of energy along the food chain for food purchases by or for U.S. households increased between 1997 and 2002 at more than six times the rate of increase in total domestic energy use. This increase in food-related energy flows is over 80 percent of energy flow increases nationwide over the period. The use of more energy-intensive technologies throughout the U.S. food system accounted for half of this increase, with the remainder attributed to population growth and higher real (inflation-adjusted) per capita food expenditures. A projection of food-related energy use based on 2007 total U.S. energy consumption and food expenditure data and the benchmark 2002 input-output accounts suggests that food-related energy use as a share of the national energy budget grew from 14.4 percent in 2002 to an estimated 15.7 percent in 2007.