The ERS energy flow analysis looked at three distinct points in time (1997, 2002, and 2007); the results cannot be used to determine a pattern or trend in food-related energy use. Many factors can and will affect energy use by the food system. Adjustments in how Americans spend their food dollars, for example, could reduce future food-related energy use.

Based on 2002 energy technologies, if households choose to substitute a portion of their at-home meat and egg consumption with expanded fish and fresh vegetable consumption, for example, there could be substantial savings in energy usage. However, the energy savings would be less if the commercial fishing industry and/or the fresh vegetable industry relied on more energy-intensive methods to meet a large increase in expenditures on fish and fresh vegetables by U.S. households.

Prices are often the most direct influence on consumer purchases and producers’ practices. If energy prices increase, for example, and labor costs and the availability of time for home food preparation do not change, companies and households will explore opportunities to trade off the now-more-expensive energy for less costly labor and time and will seek opportunities to use energy more efficiently.

Consumer attitudes about energy conservation can also alter the outlook for the level and direction of future U.S. food system energy use. For some consumers, knowledge of the energy flows associated with different food choices may influence food purchase decisions. As this segment of consumers grows, so, too, will its impact on the food system’s energy use.