Integrating nutritional and environmental impacts of animal-source foods via nutrition-based life-cycle assessment (nLCA)

Significant progress has been made in animal production systems to better understand the environmental footprints in animal-source foods by applying life-cycle assessment (LCA). However, prior LCA studies heavily focused on quantifying environmental footprints based on physical units, with less attention on the nutritional value of foods. Given that animal-source foods play a vital role in providing key nutrients, it's critical to integrate both nutrition and environmental impacts to better understand the sustainability of foods. Hence, this study aims to assess the nutritional-based cradle-to-gate environmental impacts of five animal-source foods, including pork sausage, pork ham, pork bacon, beef sausage, and beef steak, via nutrition-based LCA approach. Nutritional-environmental footprint (NEF) was quantified based on three functional units: per serving, per 50 g protein, and per 100 kcal energy. Both ranking and actual value method were applied to assess and compare each food's combined environmental and nutritional footprints. Results show that relative to pork products, beef products generally score higher environmental footprints; however, beef steak tends to rank higher when considering nutrition parameters alone. When nutritional and environmental footprints are integrated into NEF scores, pork bacon tends to receive lower NEF scores than other products under most scenarios. Although the choice of assessment methods and functional units impacts NEF scores and the product ranking, the overall pattern remains consistent. These outcomes provide insights for various stakeholders such as the animal industry to identify sustainability hotspots, policymakers to establish evidence-based product recommendations and certification guidelines, and consumers to make informed decisions.