How much food do we waste in the US? The old numbers are shocking, but new research using a different methodology produces scary numbers: “Nearly 40% of the food supply in the United States goes to waste.”
According to the ScienceNow post,
Food waste is usually estimated through consumer interviews or garbage inspections. The former method is inaccurate, and the latter isn’t geographically comprehensive. [Kevin] Hall [a quantitative physiologist at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) in Bethesda, Maryland] and his colleagues tried another approach: modeling human metabolism. They analyzed average body weight in the United States from 1974 to 2003 and figured out how much food people were eating during this period. Hall and Chow assumed that levels of physical activity haven’t changed; some researchers think that activity has decreased, but Hall and Chow say their assumption is conservative. Then they compared that amount with estimates of the food available for U.S. consumers, as reported by the U.S. government to the Food and Agriculture Organization of the United Nations.
The difference between calories available and calories consumed, they say, is food wasted. “We called it the missing mass of American food,” says co-author Carson Chow, a mathematician at NIDDK. In 2003, some 3750 calories were available daily per capita; 2300 were consumed, so 1450 were wasted, comprising 39% of the available food supply, the team reports in the November issue of PLoS ONE. This figure exceeds the 27% estimated by the U.S. Department of Agriculture (USDA) from interviews with consumers and producers.
Much of the waste is probably happening at home, say experts. A study published earlier this year by Jeffery Sobal, a sociologist at Cornell University, and colleagues examined food waste in Tompkins County, New York, through interviews. They found that production accounted for 20% of waste, distribution for about another 20%, and consumers for the remaining 60%. “Food waste used to be a cultural sin,” Sobal says.
Food Waste picture credit
For those wanting the report, The Progressive Increase of Food Waste in America and Its Environmental Impact begins
Food waste contributes to excess consumption of freshwater and fossil fuels which, along with methane and CO2 emissions from decomposing food, impacts global climate change. Here, we calculate the energy content of nationwide food waste from the difference between the US food supply and the food consumed by the population. The latter was estimated using a validated mathematical model of metabolism relating body weight to the amount of food eaten. We found that US per capita food waste has progressively increased by ~50% since 1974 reaching more than 1400 kcal per person per day or 150 trillion kcal per year. Food waste now accounts for more than one quarter of the total freshwater consumption and ~300 million barrels of oil per year.
