Start: 95.4 Last week: 87.6 This week: 87.6

Blast. Plateaued again.

The Economist alerted me to a paper in PLOS One by Kevin Hall and his colleagues at the Laboratory of Biological Modeling at the NIH in the US. The Progressive Increase of Food Waste in America and Its Environmental Impact,1 subtly published the day before Thanksgiving, concluded that America wasted close to 40% of its food supply in 2003. That figure is far higher than the USDA's own estimate of around 27%.

What is neat about this study is the methodology. Previous estimates of waste have examined small samples of garbage or interviewed people. Hall and his colleague took a different tack. They calculated the difference between food production, as revealed by the FAO’s food balance sheets for the US, and food consumption, based on a model they developed that takes the average weight of people and figures out how much they would need to eat to weigh that much. The difference, they say, is wasted, and most of their assumptions suggest that their estimate will generally be conservative. In 1974, the difference was 900 kcal per person per day. In 2003 it was 1400 kcal per person per day, a total of 150 trillion kcal per year.

I could be wrong2 but I reckon that’s 174.5 TWh, which as it happens is the annual energy consumption of Scotland and the hydroelectric production of Russia, two countries also not known for their wonderful diet. Not that it matters.

(2021-12-08: Parenthetically, as it were, is there a convention for citing wikipedia pages as they were on the day I cited them?)

What slightly surprised me about the Hall et al. study was that it took rising weight as a given and used it to estimate waste, without saying much about the consequences of obesity.3 The main thrust of their conclusion seems to be the environmental impact of throwing all that food away; water to grow it in the first place, fuel used in transport, greenhouse gas emissions in growing it and then as it decomposes, and so on. Of course that’s their privilege. But health barely gets a look in.

The calculated progressive increase of food waste suggests that the US obesity epidemic has been the result of a “push effect” of increased food availability and marketing with Americans being unable to match their food intake with the increased supply of cheap, readily available food. Thus, addressing the oversupply of food energy in the US may help curb the obesity epidemic as well as decrease food waste, which has profound environmental consequences.

That, however is precisely the point of studies by Lisa Young and Marion Nestle. Young has shown a tight correlation between food supply, portion size and obesity, a topic I’ve mentioned before. Nestle has pointed out eloquently that there is almost no lobby in the US that stands to benefit from people eating less,4 and hence no impetus to change either the amount of food produced or advice on what (and how much) to eat. In that light, maybe the push to turn food into biofuel is not such a sin, if it increases food prices at home and thus helps people to eat (and waste) less.

Perhaps it is just a coincidence, but the latest Economist Debate launched today, on the motion This house believes that governments should play a stronger role in guiding food and nutrition choices. I’ll be keeping an eye on the main contributions, but so far, I’m not impressed by either the food industry spokeswoman or the professor of psychology.

  1. Hall, K., Guo, J., Dore, M., & Chow, C. (2009). The Progressive Increase of Food Waste in America and Its Environmental Impact PLoS ONE, 4 (11) DOI: 10.1371/journal.pone.0007940  

  2. And almost all my friends who would correct me are probably busy in Copenhagen.  

  3. Note my refusal to submit to the lure of waist and waste.  

  4. Apart from the obese themselves, who would probably do something about it if they could.  

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