Legume-derived foods have been shown to have comparatively low greenhouse gas (GHG) intensities whilst providing high amounts of nutrients. However, processing legumes into meat analogues can incur significant energy costs. Here, we undertake a comprehensive life cycle assessment of plant-based and (Brazilian and Irish) beef burger patties. Sixteen impact categories are supplemented with the carbon opportunity cost of land occupation, and benchmarked against nutrient density units (NDU) to provide holistic evidence on the potential contribution of plant-based patties to environmentally-sustainable nutritional density. Plant-based patties have a smaller environmental footprint across most categories, including a 77% smaller climate change burden, but incur 8% more energy use compared with Brazilian beef patties. Normalised scores (person equivalents) were significantly larger (p