Relationship between food waste, diet quality, and environmental sustainability

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. This analysis finds that 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 necessary. Increasing consumers’ knowledge about how to prepare and store fruits and vegetables will be one of the practical solutions to reducing food waste.全球范围内，兼顾优化膳食质量与降低环境影响已成为备受关注的核心议题。过往用于关联膳食质量与可持续性的衡量指标，往往仅涵盖有限的若干指标类别，且未将食物浪费纳入考量范畴。为填补这一重要研究空白，本研究探讨了食物浪费、膳食质量、营养流失与多项可持续性衡量指标之间的关联，这些指标包括耕地占用、灌溉用水、农药与化肥使用量。本研究从美国多类官方政府数据源采集了食物摄入量、食物浪费量以及农业投入品施用率的相关数据。膳食质量通过2015健康饮食指数（Healthy Eating Index-2015）进行量化评估。本研究采用生物物理模拟模型，估算与被浪费食物相关的耕地占用量。本次分析结果显示，美国消费者日均每人浪费食物422克，每年需耗费3000万英亩耕地用于生产该部分被浪费的食物。该部分浪费的食物相当于每日可供消费热量的30%、每日可供消费食物总重量的四分之一，以及年度耕地总使用面积的7%。膳食质量越高，对应的食物浪费量、被浪费的灌溉用水与农药使用量往往越高，但耕地浪费量则相对更低。这一现象主要源于果蔬类食物：其既具有健康促进功效，所需耕地占用量较低，但农业投入品消耗量却相当可观。上述研究结果表明，需同时推进优化膳食质量与减少食物浪费两项工作。提升消费者关于果蔬制备与储存的相关知识储备，将成为减少食物浪费的切实可行路径之一。