Greener patties? Evaluating environmental and nutritional trade-offs across aquatic, plant-based, and animal options

Abstract Transitioning to sustainable food systems requires balancing nutritional adequacy and environmental sustainability. However, aquatic or blue foods are often underrepresented in comparative studies assessing the environmental impacts and nutritional quality, particularly those that integrate environmental assessment with nutritional metrics such as protein and iron, leading to an incomplete understanding of their potential role in healthy and climate-resilient food systems. This study addresses that gap by evaluating the environmental and nutritional trade-offs of nine patty types—including aquatic (salmon, cod, mussels, seaweed), plant-based (chickpea, beetroot), and terrestrial animal-based (beef, pork/veal, chicken) options. An integrated framework combining lifecycle assessment (LCA), nutritional profiling, and consumer behaviour analysis was applied. Environmental impacts were quantified using LCA aligned with planetary boundaries, while a nutritional LCA incorporated key metrics such as protein and iron content. A stated preference survey, conducted among Danish consumers, assessed how carbon footprint and nutrient information influenced consumer willingness to try and pay for each patty type. Results indicate that terrestrial animal-based patties, particularly beef and pork/veal, exhibit the highest environmental burdens per nutrient-standardised serving. In contrast, aquatic options, particularly mussels and seaweed, along with plant-based patties, demonstrated lower environmental impacts. Mussels emerged as a nutrient-dense and environmentally favourable blue food with promising consumer acceptance when paired with sustainability disclosures. By explicitly incorporating blue foods into a comparative sustainability framework, this study highlights their underexplored potential in contributing to equitable, nutrition-sensitive, and climate-resilient food systems. The integration of environmental, nutritional (protein and iron), and behavioural insights supports more inclusive and data-driven food policy and innovation for the future.