Transforming food systems to provide better nutritional and health outcomes at reduced environmental costs has been identified as one of the most significant challenges of this time. Nutritional Life Cycle Assessment (nLCA), a novel methodology that integrates nutritional science into the environmental life cycle analysis framework, plays a pivotal role in this transformation. Its application ensures that the food and diets selected meet human health and nutritional requirements without compromising the ecosystem for future generations to come. However, nLCA may also come with several risks and uncertainties from data and methodological choices. The present entry, therefore, provides an overview and guide towards a better application of the nLCA and outlines the most relevant gaps and issues that require attention by the scientific community.