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Don't know where to start? Read about all the issues of food energy use and sustainability here. Links to actions which relate to each issue can be found in orange.

food summary "In 2007, the U.S. food system accounted for almost 16 percent of the Nation's energy budget." -USDA Economic Research Service

Issues surrounding the sustainability of our food system occur at all stages of the life-cycle of food production and consumption. It is important to understand what the issues are at the various stages, beginning with agricultural production, then transport and distribution, processing and packaging, preparation and cooking, and ending with the detrimental effects all of these stages have on greenhouse gas (GHG) emissions, soil and water contamination and food waste. While some of the stages of the food system present larger problems than others, it is important to recognize at which stages individuals have the power to make change in their daily lifestyles and which stages require larger system and policy change. The graphic to the right was adapted from Heller and Keoleian, 200; FAO, 1996.

  • Preparation and cooking (42%)
  • Processing and packaging (23%)
  • Transport and distribution (14%)
  • Agricultural Production (21%)

According to a report done by the USDA Economic Research Service in March 2010, "Between 1997 and 2002, over 80 percent of the increase in annual U.S. energy consumption was food related."

The report identifies three main reasons why food related energy has increased so dramatically even as other energy use has remained stable:

  • (1) Population growth has accounted for 25% of food-related energy use. Our nationwide population has grown by more than 14 million in the five years from 1997 to 2002. More mouths to feed.

  • (2) While there has been a greater proportion of foods that used less energy (fresh produce, fish...) purchased over energy-intensive processed foods, this change came with a "substantial increase in food marketed per capita to U.S. consumers." People are eating more food.

  • (3) We are using more energy-intensive technologies that account for about half of the increase in food-energy. Businesses are faced with increasing labor costs, and while energy costs are low it is more economical to put machines to work. As a result, "there has been a shift from human labor to energy-using equipment occurring in all food and food-related commodity groups" (USDA).


In the United States, the most frequently cited statistic is that food travels 1,500 miles on average from farm to consumer. That figure comes from work led by Rich Pirog, the associate director of the Leopold Center for Sustainable Agriculture at Iowa State University. In 2001, in some of the country's first food-miles research, Pirog and a group of researchers analyzed the transport of 28 fruits and vegetables to Iowa markets via local, regional, and conventional food distribution systems. The team calculated that produce in the conventional system—a national network using semitrailer trucks to haul food to large grocery stores—traveled an average of 1,518 miles (about 2,400 kilometers). By contrast, locally sourced food traveled an average of just 44.6 miles (72 kilometers) to Iowa markets.

In light of such contrasts, the admonition to "eat local" just seems like common sense. And indeed, at the most basic level, fewer transport miles do mean fewer emissions. Pirog's team found that the conventional food distribution system used 4 to 17 times more fuel and emitted 5 to 17 times more CO2 than the local and regional systems (the latter of which roughly meant Iowa-wide). Similarly, a Canadian study estimated that replacing imported food with equivalent items locally grown in the Waterloo, Ontario region would save transport-related emissions equivalent to nearly 50,000 metric tons of CO2, or the equivalent of taking 16,191 cars off the road" (WorldWatch Institute, 'Is Local Food Better'?).

The amount of food which is imported to the United States has been steadily rising since 1970, which implies that the average food miles for many produce items has been increasing over time (Leopold Center). According to Melissa Laska, a healthy food researcher who spoke at the annual Healthy Foods Healthy Lives conference at the University of Minnesota in 2010, the breakdown of imported food to the US is as follows:

  • 79% of fish
  • 16% of wine/beer
  • 32% of fruit/nuts
  • 13% of vegetables
  • 12% of grains
  • 11% of sweets
  • 11% of red meat

In addition, many countries have very specific food export markets. For example, 98% of our limes come from Mexico, 51% of our garlic comes from China, and only 8 countries account for 80% of spices used in the United States (Healthy Foods, Healthy Lives).

Most fresh fruits and vegetables produced in the U.S. are shipping from California, Florida and Washington. (Leading Producer States by Commodity Groups, 2001. Economic Research Service Web site.

Fruits and vegetables shipped from distant states and countries can spend as many as seven to fourteen days in transit before they arrive in the supermarket. (Mary S. Choate., A Good Tomato in Winter, Where??Co-op Food Stores Web site

Buying local decreases the distance food must travel. In doing so, it reduces carbon dioxide emissions from trucking and requires less packaging materials needed to keep food fresh while travelling. In addition, the local food found at 'farmers markets, through CSA programs or at a grocery store or co-ops is usually fresh or minimally processed and can be more energy-efficient than purchasing heavily processed and packaged supermarket goods (Bomford, 2011; FAO).

Locally grown fruits and vegetables are usually sold within 48 hours of being harvested. Produce picked and eaten at the height of ripeness has exceptional flavor and, when handled properly is packed with nutrients. By choosing local produce at farm stands, farmers markets, pick-you-own farms and grocery stores, you pay for taste, not transportation and packaging. Buying local also provides an opportunity to connect with the wide variety of produce which is grown by local farmers throughout the season. Most fruit and vegetable varieties sold in supermarkets are chosen for their ability to withstand industrial harvesting equipment and extended travel not taste. This results in little variety in the plants grown.


Unfortunately, food transport may only be a fraction of the total energy put into the U.S. food system. Much new data suggests that what you eat matters at least as much as how far it is transported. Beyond the issues of food types, food production is also a huge energy user. According to a study done by the WorldWatch Institute:

In a paper published last year, Christopher Weber and H. Scott Matthews, of Carnegie Mellon University, wove together data from a variety of U.S. government sources into a comprehensive life-cycle analysis of the average American diet. According to their calculations, final delivery from producer or processor to the point of retail sale accounts for only 4 percent of the U.S. food system's greenhouse gas emissions. Final delivery accounts for only about a quarter of the total miles, and 40 percent of the transport-related emissions, in the food supply chain as a whole. That's because there are also "upstream" miles and emissions associated with things like transport of fertilizer, pesticides, and animal feed. Overall, transport accounts for about 11 percent of the food system's emissions. (WorldWatch Institute, 'Is Local Food Better'?)

According to the Food and Agriculture Organization of the United States (FAO), a household that substitutes red meat and dairy products consumption for vegetable-based protein for just one day could achieve the same GHG mitigation benefits as if they had bought all their weekly food from local providers and avoided the energy used for transport (FAO). A report done by the Worldwatch Institute conveys the following:

"...[Agriculture's] overwhelming "hotspots" are red meat and dairy production. In part that's due to the inefficiency of eating higher up on the food chain-it takes more energy, and generates more emissions, to grow grain, feed it to cows, and produce meat or dairy products for human consumption, than to feed grain to humans directly. But a large portion of emissions associated with meat and dairy production take the form of methane and nitrous oxide, greenhouse gases that are respectively 23 and 296 times as potent as carbon dioxide. Methane is produced by ruminant animals (cows, goats, sheep, and the like) as a byproduct of digestion, and is also released by the breakdown of all types of animal manure. Nitrous oxide also comes from the breakdown of manure (as well as the production and breakdown of fertilizers). Red meat specifically is responsible for about 150 percent more emissions than chicken and fish. No matter how it is measured, on average red meat is more GHG-intensive than all other forms of food" (Tara Garnett, via Worldwatch Institute).

Changing to a diet low in red meat and milk products can be an effective means of lowering a household's carbon and energy footprint.

Although lower on the food chain, vegetable and grain crops still require energy to be produced. Much of this energy is embodied in the nitrogen fertilizers used as well as the diesel fuel used for farm equipment and distribution. However, the estimates for the agricultural production of plants is much lower. For example, wheat production is estimated to consume 3.9 MJ/kg of food, almost 1/8th the average of the lowest-energy consuming meat products.

"Broadly speaking, eating fewer meat and dairy products and consuming more plant foods in their place is probably the single most helpful behavioral shift one can make to reduce food-related greenhouse gas emissions," Garnett argues.

For those not willing to give up red meat entirely, there is a compelling counter-argument in eating only grass-fed beef.

A diet of grazed grass requires much less fossil fuel than a feedlot diet of dried corn and soy. On pasture, grazing animals do their own fertilizing and harvesting. The ground is covered with greens all year round, so it does an excellent job of harvesting solar energy and holding on to top soil and moisture. In addition, grazed pasture removes carbon dioxide from the atmosphere more effectively than any land use, including forestland and ungrazed prairie, helping to slow global warming and climate change.

In addition to requiring less energy, well-managed pasture absorbs far more rain water than most other land uses, allowing more water to return to underground aquifers rather than being used to water crops. Grazed lands all help slow global warming by removing carbon dioxide from the air. Well-managed grazing lands provide much-needed habit for wildlife, reduce water runoff, and provide cleaner, more abundant water for wildlife and human use (NRCS).

While eating less meat is an alternative option for reducing the impact diet has on the environment, eating meat from well-managed grazing animals has been shown to provide a net benefit to the planet.

Beyond an argument of meat vs. not, the energy and material that goes into producing all food (both meat and vegetables) can be lessened through organic agriculture.

"Organic food is produced by farmers who emphasize the use of renewable resources and the conservation of soil and water to enhance environmental quality for future generations. Organic meat, poultry, eggs, and dairy products come from animals that are given no antibiotics or growth hormones. Organic food is produced without using most conventional pesticides; fertilizers made with synthetic ingredients or sewage sludge; bioengineering; or ionizing radiation. Before a product can be labeled 'organic,' a Government-approved certifier inspects the farm where the food is grown to make sure the farmer is following all the rules necessary to meet USDA organic standards. Companies that handle or process organic food before it gets to your local supermarket or restaurant must be certified, too."
Consumer Brochure, USDA National Organic Program

A significant amount of energy in the food production phase goes into nitrogen fertilizers and diesel fuel to power farm machinery. These are both petroleum-based resources which are used less frequently or not at all on organic farms.


Beyond the farm gate, heavy processing and packaging of food for longer shelf life accounts for 23% of the energy put into the food system, compared to only 14% attributed to transport and distribution.

While eating less processed food is a mantra related most prevalently to eating a healthier diet, eating less processed food also has the potential to create significant change in living a more sustainable lifestyle. We are using more energy-intensive technologies for food processing that account for about half of the increase in food-energy according to a report done by the USDA Economic Research Service in March 2010.

A significant amount of energy is used in food every year from agricultural machinery and fuel for these machines, transportation of food, food processing, food packaging, ovens, stoves, microwaves, home appliances, and even in manufacturing of the cookware used to make food (USDA).


When food is wasted, the embedded energy is also wasted. About one-third of food produced is lost or wasted globally and this food loss in the US accounts for 2 percent of total annual energy consumption (Cueller and Weber, 2010 via FAO). While food losses occur at all stages of the supply chain, in high-GDP counties such as the United States, considerable amounts of food are wasted due to poor purchase planning, careless preparation, or leaving prepared food unconsumed. Food waste in European and North American counties is between 95-115 kg per capita per year (Gustavsson et all., 2011 via FAO), whereas in areas where food is relatively scarce such as sub-Saharan Africa, losses are between 6-11 kg per capita per year. Avoiding food losses and waste throughout the supply chain could reduce energy inputs into the food system and reduce GHG emissions, lessen the competition for land and water, cut food costs and alleviate poverty and hunger (FAO).