The trend in the consumption of unconventional, more nutritious foods is leading to the globalization and decentralization of their production, giving rise to the adaptation and innovation of traditional products to make them healthier and more sustainable. This article focuses on quinoa and aims to estimate the environmental impacts of its production adapted to the Spanish conditions and of potential derived snacks enriched with this pseudo cereal by applying conventional and nutritional life cycle assessment (LCA) methodologies. Besides, an exhaustive study of the energy flows by measuring the cumulative energy demand and the calculation of the energy return of investment (EROI) is carried out to assess the most impactful aspect of the processing industries. The application of cradle to gate LCA revealed that polluting emissions of Spanish quinoa are rather similar to those of the Andean grain, with an impact on climate change of 1.03 kg CO2 eq./kg. However, high resource footprints were obtained, for instance a water deprivation potential of 60 m3/kg due to the scarcity in this country. Besides, the consideration of a nutrient profile model as functional unit led to the conclusion that quinoa-based snacks are generally more environmentally sustainable than their conventional counterparts in terms of climate change, resources consumption or water degradation. EROI scores were relatively low for all options, with only between 1.77 and 4.35 % of the energy invested returned, which evidences the unsustainable agricultural practices and low efficiency of processing units. Based on this research, producers can reorient production systems in support of nature, and consumers are able to guide their choices towards improved eating patterns.