Eat Less, Drive More: Dieting Could Reduce Oil Imports

By Brad Zigler

You want to save the planet? Then go on a diet. That'd be the advice of Cornell University professor David Pimentel anyway. To understand why the good professor would proffer such counsel, take a moment to consider his recent research.

The American food supply is driven almost entirely by nonrenewable energy sources, says Pimentel, the cost of which is only likely to rise in the future. Our total energy consumption of petroleum, natural gas, coal and other mined fuels costs $700 billion a year. Since more than 90% of domestic oil deposits have been depleted, we're now importing over 65% of our oil at an annual cost of $200 billion.

Our food system accounts for 19% of the nation's total energy use, according to Pimentel. Agricultural production, including food processing and packaging, consumes 14%, while transportation and preparation uses another 5%.

Pimentel's most recent study, titled "Reducing Energy Inputs in the US Food System," offers a game plan to cut as much as 50% of the fossil energy cost of producing and preparing our food, including suggestions for changes in production, processing, packaging, transport and consumption.

Pimentel's proposals on the production side include using smaller on-farm machinery - and, consequently, less fuel - in addition to replacing nitrogen-based fertilizers with cover crops and manure, as well as altering tillage and conservation techniques to further reduce soil erosion.

Game Plan

On the processing and packaging side, Pimentel advocates a number of improvements at the plant level including the employment of modern, appropriately sized equipment and reducing the number of packaging layers for some goods.

Transportation of food throughout processing and final movement to market is grossly energy inefficient by Pimentel's reckoning. American food travels an average of 1,500 miles before it is consumed, he says. On average, the energy expended to transport our food is 1.4 times the energy in the food itself. For some categories of food, the ratio is a lot higher. Moving fruits and vegetables by air cargo, for example, uses four times the energy provided by the food. A reduction in transport distances, claims Pimentel, could easily lead to substantial energy savings.

Pimentel's supply-side recommendations for improving efficiencies in food production, processing and transportation only gets us part of the way to halving our energy expenditures. The most interesting suggestions he makes deal with demand. Simply put, Pimentel says America needs to go on a diet. Reducing total caloric intake and limiting our consumption of junk food gets us the rest of the way to meaningful energy savings. 

Requirements for a Total 50% Reduction in Energy Inputs

Change	Reduction Obtained
Production technology improvements	50%
Food processing/packaging improvements	50%
Food transportation reductions	50%
Reduction in food consumption	30%
Junk food reduction	80%

The average American consumes 3,747 calories per day despite the U.S. Food and Drug Administration's recommendation for an average daily intake of 2,000 to 2,500 calories. Just following the FDA's diet recommendation, says Pimentel, could significantly reduce the energy used in food production.

"The fossil energy required to produce the relatively high level of animal products consumed in the average American diet are estimated to be 50% of the total energy inputs," says Pimentel, "while to produce staple foods such as potatoes, rice, common fruits and vegetables, uses about 20% of the fossil energy inputs." 

In contrast to the American diet, Pimentel points to a 2002 study of the Dutch diet, where animal products account for only 36% of the total energy inputs, and staples another 12%. 

Current Daily American Diet vs. FDA Recommendations

Food Item	Current Diet Calories	Portion of Diet	FDA Diet Calories	Portion of Diet	Caloric Reduction
Grains	1,509	40%	1,283	51%	15%
Fats/oils	581	16%	203	8%	86%
Meats	526	14%	263	11%	50%
Milk	404	11%	242	10%	65%
Sweeteners	282	8%	100	4%	65%
Starchy roots	136	4%	116	5%	15%
Fruits	126	3%	126	5%	0%
Vegetables	80	2%	80	3%	0%
Eggs	61	2%	61	2%	0%
Fish	28	1%	14	1%	50%
Nuts	15	0%	15	1%	0%
Total	3,747	100%	2,503	100%	33%

Viewed another way, the annual energy intake of the average American is roughly equivalent to that contained in a barrel of crude oil (in actuality, it's 5.428 mmBTU, or the energy available in 39 gallons of crude). Adhering to FDA guidelines on fats and oils, the average American would save the energy equivalent of four gallons of crude oil annually. Reducing meat consumption knocks down demand by three gallons. In fact, if the FDA could convince the citizenry to consume no more than 2,500 calories a day, nationwide energy demand would fall by the equivalent of 285.7 million barrels of crude, an amount nearly equal to the current domestic oil inventory outside of the Strategic Petroleum Reserve.

Even greater efficiency can be obtained by modifying the origin of the calories consumed. The average American, claims Pimentel, ingests 33% of his/her total calories through junk food. Reducing junk food intake from 33% to 10% alone, he says, would reduce our average intake to 2,826 calories, conserving energy while improving overall health. An ounce of potato chips, Pimentel reminds us, contains 160 calories of food energy; an ounce of potatoes only 16.

To put this into perspective, think of the annualized energy cost of a once-a-week fast-food habit: 

Annualized Once-A-Week Energy Cost

Fast Food Meal	Calories	Crude Oil Equivalent
McDonald's Big Mac with cheese, medium french fries, 12 oz. strawberry milk shake	1,503	2 ¼ gallons
KFC 3 pcs. chicken, cole slaw, mashed potatoes with gravy, medium Pepsi	1,140	1 ¾ gallons
Taco Bell Beef Burrito Supreme, Mexican rice, Pintos ‘n Cheese, medium Pepsi	1,030	1 ½ gallons

Simply shunning your weekly Big Mac meal lets you drive your Ford Taurus an extra 28 miles. That seems like a good trade-off, don't you think?