Americans avert energy crisis by dieting, study reveals... Answered
Scientists at Cornell University, led by David Pimintel, have performed a meta-study and found that the easiest way for Americans to reduce, and even totally avoid, the looming energy crisis is to go on a diet.
The average American consumes about 3747 kcal per day compared to the 2000 to 2500 kcal per day recommended by the US Food and Drug Administration. (This does not include junk food!)
Producing those daily calories uses the equivalent to 2000 litres of oil per person each year. That accounts for about 19% of US total energy use.
Pimentel estimated 6 kilograms of plant protein are needed to produce 1 kg of high quality animal protein. He calculates that if Americans maintained their 3747 kcals per day, but switched to a vegetarian diet, the fossil fuel energy required to generate that diet would be cut by one third.
Pimentel calculates that the equivalent of 2100 kcal go into producing a can of diet soda which contains a maximum of 1 kcal. About 1600 kcal go into producing the aluminium can alone.
Other suggested changes to the food production process range from replacing incandescent bulbs with energy-saving fluorescent ones, to using fewer machines, pesticides and fertilisers, and more human power on farms.
Reducing the distance that food is transported could also cut energy costs: food travels 2400 km on average to its consumer in the US. This requires 1.4 times the energy actually contained in the food. Producing food locally would cut the energy expended transporting it by half.
Implementing all the suggested changes would cut the US food industry's energy bill in half.
New Scientist article
New Scientist Environment Section, special report of energy and fuels