Measures and metrics of sustainable diets with a focus on milk, yogurt, and dairy products

The 4 domains of sustainable diets are nutrition, economics, society, and the environment. To be sustainable, foods and food patterns need to be nutrient-rich, affordable, culturally acceptable, and sparing of natural resources and the environment. Each sustainability domain has its own measures and metrics. Nutrient density of foods has been assessed through nutrient profiling models, such as the Nutrient-Rich Foods family of scores. The Food Affordability Index, applied to different food groups, has measured both calories and nutrients per penny (kcal/$). Cultural acceptance measures have been based on relative food consumption frequencies across population groups. Environmental impact of individual foods and composite food patterns has been measured in terms of land, water, and energy use. Greenhouse gas emissions assess the carbon footprint of agricultural food production, processing, and retail. Based on multiple sustainability metrics, milk, yogurt, and other dairy products can be described as nutrient-rich, affordable, acceptable, and appealing. The environmental impact of dairy farming needs to be weighed against the high nutrient density of milk, yogurt, and cheese as compared with some plant-based alternatives.