Achieving a sustainable global food chain is becoming particularly acute as modern Western diets are adopted in a growing number of countries and cultures around the world. Understanding the consequences that this shift has on health and sustainability is important. This exploratory study is the first to apply the life cycle assessment (LCA) methodology to analyze the sustainability implication of ongoing dietary shifts in Greenland, where locally hunted seal meat is increasingly being replaced by imported livestock products, primarily pig and poultry produced in Denmark. This dietary shift, indirectly driven by international trade bans such as the EU seal product ban, has sustainability implications. To inform and support more comprehensive analyses and policy discussions, this paper explores the sustainability of these parallel Greenlandic food supply chains. A quantitative comparison of the greenhouse gas emissions of Greenlandic hunted seal and Danish pig and poultry is complemented by a qualitative discussion of nutrition, cultural food preferences, animal welfare, and the use of land, pesticides and antibiotics. Although the variability in the life cycle inventory data collected from Greenlandic hunters was considerable, greenhouse gas emissions of seal meat were consistently lower than those of imported livestock products. Emissions of the latter are dominated by biogenic emissions from feed production and manure management, while these are absent for seal meat, whose emissions instead are dominated by fossil fuel use. The implications of these results for sustainable national food policies in a modern global context as well as important areas for additional research are discussed. © 2021 by the authors.