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焦点，但人们对一个国家不同社会经济群体的饮食模式的影响，以及这些群体的营养质量和饮食对环境影响之间的权衡知之甚少。我们使用环境扩展投入产出分析评估美国家庭饮食模式对整个供应链的温室气体排放、蓝水足迹、土地使用和能源消耗的影响。我们使用跨个人收入和其他社会经济特征的健康饮食指数得分来比较这些饮食模式的营养质量。收入或教育水平较高的人更有可能采用更健康的饮食，但也要对饮食对环境造成的更大影响负责，这主要是由于乳制品和畜产品、海鲜以及能量密度较低但营养密度较高的食物的消费量较高。我们的优化表明，几乎 95% 的人都可以在当前的食品预算范围内实现对环境影响较小的健康饮食，并使与食品相关的温室气体排放量平均减少 2%，土地使用量平均减少 24%，能源使用量平均减少 4%消耗量，但蓝水消耗量增加了 28%。然而，对于收入和教育程度最低的群体中 38% 的黑人和西班牙裔人来说，这种饮食模式是负担不起的。