If Not to Waist, to Waste

November 28, 2009

We have all been hearing reports for years about how rapidly Americans (and to a lesser degree, people in some other rich countries) are getting fatter.  Certainly, anyone who has walked around a shopping mall recently knows that there is plenty of pork on the hoof out there; and it’s been suggested that the industrialization of food production, and the push to sell more food, has contributed to this.

The current issue of The Economist has a report on some new research that suggests that, in addition to having larger waistlines, Americans are wasting more food than ever before.  A new paper, by four researchers at the National Institute of Diabetes and Digestive and Kidney Diseases, published in the online journal PLoS One at the Public Library of Science, compares the amount of food produced in the US, adjusted for imports and exports, with the daily calorie consumption based on nutritional surveys carried out by the Centers for Disease Control and Prevention.

Despite the clear evidence that a lot of food is being consumed, the researchers found that a lot was being thrown away, as well.  The amount wasted works out to about 40% of total calories produced:

They found that the average American wastes 1,400 kilocalories a day. That amounts to 150 trillion kilocalories a year for the country as a whole—about 40% of its food supply, up from 28% in 1974.

(A kilocalorie here is the same unit that is usually called just a calorie on food labels.)  This degree of waste is obviously a bit troubling in a world where a large number of people have trouble getting enough to eat.  It also has significant environmental costs.

Producing these wasted calories accounts for more than one-quarter of America’s consumption of freshwater, and also uses about 300m barrels of oil a year. On top of that, a lot of methane (a far more potent greenhouse gas than carbon dioxide) emerges when all this food rots.

Although the United States as a whole has adequate supplies of fresh water, they are not uniformly distributed; and irrigated agriculture is a prodigious consumer of water in some relatively dry areas.

As the Economist article points out, some of this waste probably occurs because food is inexpensive enough that it can make economic sense for suppliers to have, on average, some excess inventory, to avoid the opportunity costs of being out of stock.  Still, particularly in the current environment which has some people, even in rich societies, struggling to make ends meet, the idea of squandering so much of an essential resource is troubling.