Relationship between food waste, diet quality, and environmental sustainability

Authors: Conrad, Zachary; NILES, MEREDITH - University Of Vermont; NEHER, DEBORAH - University Of Vermont; ROY, ERIC - University Of Vermont; TICHENOR, NICOLE - University Of New Hampshire; Jahns, Lisa

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2018
Publication Date: 4/18/2018
Citation: Conrad, Z.S., Niles, M., Neher, D.A., Roy, E.D., Tichenor, N.E., Jahns, L.A. 2018. Relationship between food waste, diet quality, and environmental sustainability. PLoS One. 13(4):e0195405. https://doi.org/10.1371/journal.pone.0195405.
DOI: https://doi.org/10.1371/journal.pone.0195405

Interpretive Summary: More efforts are needed to improve diet quality while also minimizing environmental impact. Food waste is a key driver of environmental impact, but little research has examined the relationship between diet quality, food waste, and environmental sustainability. In this study we combined data on food consumption and food waste at the national level from several sources, in order to estimate the amount of food wasted per person. We then used a computer model to estimate the amount of cropland associated with wasted food, and to estimate the amount of agricultural irrigation water, pesticides, and fertilizers wasted. We found that, on average, Americans wasted just under one pound of food per person every day, and 30 million acres of cropland were used to produce this wasted food every year. Higher quality diets were associated with greater amounts of food waste, which leads to greater amounts of wasted irrigation water and pesticides, but not fertilizers. Interestingly, this is largely due to fruits and vegetables, which are health-promoting and require relatively small amounts of cropland, but require high amounts agricultural inputs. To improve diet quality and minimize environmental impact, individuals should consume more fruits and vegetables and also waste less of them.

Technical Abstract: Improving diet quality while simultaneously reducing environmental impact is a critical focus globally. Metrics linking diet quality and sustainability have typically focused on a limited suite of indicators, and have not included food waste. To address this important research gap, we examine the relationship between food waste, diet quality, nutrient waste, and multiple measures of sustainability: use of cropland, irrigation water, pesticides, and fertilizers. Data on food intake, food waste, and application rates of agricultural amendments were collected from diverse US government sources. Diet quality was assessed using the Healthy Eating Index-2015. A biophysical simulation model was used to estimate the amount of cropland associated with wasted food. US consumers wasted 422g of food per person daily, with 30 million acres of cropland used to produce this food every year. This accounts for 30% of daily calories available for consumption, one-quarter of daily food (by weight) available for consumption, and 7% of annual cropland acreage. Higher quality diets were associated with greater amounts of food waste and greater amounts of wasted irrigation water and pesticides, but less cropland waste. This is largely due to fruits and vegetables, which are health-promoting and require small amounts of cropland, but require substantial amounts of agricultural inputs. These results suggest that simultaneous efforts to improve diet quality and reduce food waste are critical, because these efforts are not necessarily mutually inclusive. Increasing consumers’ knowledge about how to prepare and store fruits and vegetables will be one of the practical solutions to reducing food waste.