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August 03, 2010

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America’s food waste laying “waste” to environment

Nov. 25, 2009
Courtesy Public Library of Science
and World Science staff

Amer­i­ca’s food waste con­tri­butes to ex­cess con­sump­tion of fresh wa­ter and fos­sil fu­els which—along with emis­sions from de­com­pos­ing food—can wors­en glob­al cli­mate change, scient­ists say.

In a pa­pe­r pub­lished in on­line sci­en­tif­ic jour­nal PLoS One, Kev­in Hall and col­leagues at the U.S. Na­tional In­sti­tute of Di­a­be­tes and Di­ges­tive and Kid­ney Dis­eases cal­cu­lat­ed the en­er­gy con­tent of na­tion­wide food waste from the dif­fer­ence be­tween the U.S. food supply and the food eat­en by the popula­t­ion.

Amer­i­ca’s food waste con­tri­butes to ex­cess con­sump­tion of fresh wa­ter and fos­sil fu­els which—along with emis­sions from de­com­pos­ing food—can wors­en glob­al cli­mate change, scient­ists say.
The lat­ter was es­ti­mat­ed us­ing a math­e­mat­i­cal mod­el of hu­man me­tab­o­lism re­lat­ing body weight to amount of food eat­en.

The re­search­ers found that pe­r-capita food waste has pro­gres­sively in­creased by about 50 per­cent since 1974, reach­ing more than 150 tril­lion Calo­ries year­ly. Pre­vi­ous cal­cula­t­ions are likely to have un­deres­ti­mat­ed the waste by as much as 25 per­cent, the group said.

This cal­cu­lat­ed in­crease of food waste sug­gests that the U.S. obes­ity ep­i­dem­ic may have been the re­sult of a “push ef­fect” of in­creased food avail­abil­ity and mar­ket­ing with Amer­i­cans un­able to match their food in­take with the in­creased supply of cheap food, the sci­en­tists con­tin­ued.

Hall and col­leagues sug­gest that ad­dress­ing the over­supply of food en­er­gy in the coun­try could help curb the obes­ity ep­i­dem­ic as well as re­duce food waste, which would have pro­found con­se­quenc­es for the en­vi­ron­ment and nat­u­ral re­sources. For ex­am­ple, food waste is now es­ti­mat­ed to ac­count for more than one quar­ter of the to­tal freshwa­ter con­sump­tion and more than 300 mil­lion bar­rels of oil per year rep­re­sent­ing about 4 per­cent of the to­tal U.S. oil con­sump­tion.

This, along with re­lat­ed emis­sions of meth­ane and car­bon di­ox­ide, “im­pacts glob­al cli­mate change,” Hall and col­leagues wrote. “Sur­pris­ingly lit­tle dis­cus­sion has been de­vot­ed to the is­sue of food waste,” they added.

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America’s food waste contributes to excess consumption of fresh water and fossil fuels which, along with emissions from decomposing food, can worsen global climate change In a paper published in online scientific journal PLoS One, Kevin Hall and colleagues at the U.S. National Institute of Diabetes and Digestive and Kidney Diseases calculated the energy content of nationwide food waste from the difference between the U.S. food supply and the food eaten by the population. The latter was estimated using a mathematical model of human metabolism relating body weight to amount of food eaten. The researchers found that per-capita food waste has progressively increased by about 50% since 1974 reaching more than 150 trillion Calories yearly. Previous calculations are likely to have underestimated the waste by as much as 25%, the group said. This calculated increase of food waste suggests that the U.S. obesity epidemic may have been the result of a “push effect” of increased food availability and marketing with Americans unable to match their food intake with the increased supply of cheap food, the scientists continued. Hall and colleagues suggest that addressing the oversupply of food energy in the country could help curb to the obesity epidemic as well as reduce food waste, which would have profound consequences for the environment and natural resources. For example, food waste is now estimated to account for more than one quarter of the total freshwater consumption and more than 300 million barrels of oil per year representing about 4% of the total U.S. oil consumption. This, along with related emissions of methane and carbon dioxide, “impacts global climate change,” Hall and colleagues wrote. “Surprisingly little discussion has been devoted to the issue of food waste,” they added.