He Pan, Feng Kuishuang, Baiocchi Giovanni, Sun Laixiang, Hubacek Klaus
Department of Earth System Science, Tsinghua University, Beijing, China.
School of Earth and Ocean Sciences, Cardiff University, Cardiff, UK.
Nat Food. 2021 Sep;2(9):664-672. doi: 10.1038/s43016-021-00350-5. Epub 2021 Aug 30.
Environmental implications of food choice are the focus of increasingly extensive research, but less is known about the impacts of dietary patterns of different socio-economic groups of a country, and the trade-offs between nutritional quality and environmental impacts of diet within those groups. We evaluate the impacts of US household dietary patterns on greenhouse gas emissions, blue water footprint, land use and energy consumption across supply chains using an environmentally extended input-output analysis. We compare the nutritional quality of these dietary patterns using healthy eating index scores across individuals' income and other socio-economic characteristics. Individuals with higher income or education levels are more likely to adopt healthier diets but are also responsible for larger environmental impacts of diet primarily due to a higher consumption of dairy and livestock products, seafood and items with lower energy density but higher nutrient density. Our optimization shows that a healthy diet with lower environmental impacts is achievable within current food budgets for almost 95% of people, and results in average decreases of 2% in food-related greenhouse gas emissions, 24% in land use and 4% in energy consumption, but a 28% increase in blue water consumption. However, such dietary patterns are unaffordable for 38% of Black and Hispanic individuals in the lowest income and education groups. Policies that affect income and food prices making nutritious food more affordable would be needed to achieve better nutrition and improved environmental outcomes simultaneously, particularly for more vulnerable socio-economic groups.
食物选择对环境的影响是越来越广泛研究的重点，但对于一个国家不同社会经济群体的饮食模式的影响，以及这些群体饮食的营养质量与环境影响之间的权衡，我们所知甚少。我们使用环境扩展投入产出分析方法，评估美国家庭饮食模式对整个供应链中的温室气体排放、蓝水足迹、土地利用和能源消耗的影响。我们使用健康饮食指数得分，根据个人收入和其他社会经济特征，比较这些饮食模式的营养质量。收入或教育水平较高的个体更有可能采用更健康的饮食，但他们的饮食对环境的影响也更大，这主要是由于他们对乳制品、畜产品、海鲜以及能量密度较低但营养密度较高的食品的消费量较高。我们的优化分析表明，对于近95%的人来说，在当前食品预算范围内可以实现对环境影响较小的健康饮食，这会使与食品相关的温室气体排放量平均降低2%，土地利用减少24%，能源消耗减少4%，但蓝水消费量会增加28%。然而，这种饮食模式对于收入和教育水平最低群体中38%的黑人和西班牙裔个体来说是难以承受的。要同时实现更好的营养和改善环境状况，特别是对于更脆弱的社会经济群体，就需要出台影响收入和食品价格、使营养食品更具可承受性的政策。
