Differences in plant- and animal-based protein sources consumed across socioeconomic groups in The Netherlands and their associated environmental impact

This study explored the differences in sources of protein (SOP) consumed across socioeconomic groups in the Netherlands and their environmental impact. Using data from the Dutch National Food Consumption Survey 2019–2021, 1746 participants aged 18–79 years were included. Socioeconomic status (SES) was determined by education level. Protein sources included nuts and seeds, dairy, red meat, poultry, processed meats, fish, legumes, meat substitutes, and eggs. Environmental impact (EI) was assessed using data from life cycle assessment (LCA), considering greenhouse gas (GHG) emissions, land use (LU) and water use (WU). Dietary intake was estimated using two non-consecutive 24-h dietary recalls and reported in g/day; fish consumption was converted to g/w for this study. Linear and logistic regressions were applied to explore the associations between SES (predictor variable) and SOP and EI indicators (response variables). Compared to the high SES group, individuals with low SES consumed more red meat, processed meat, and dairy (p for trend < 0.05 for all), and less nuts and seeds (p < 0.001), fish (p = 0.004). They were less likely to consume meat substitutes (p < 0.001). No significant differences were found for poultry, eggs, and legumes consumption. Individuals with low SES showed greater total GHG emissions and LU but lower WU (p < 0.05 for all). Across all SES groups, animal-based protein sources (ABPs) contributed the most to GHG emissions, LU and WU, while plant-based protein sources (PBPs) contributed minimally. Individuals with low SES tend to consume more ABPs, and were associated with greater GHG emissions and LU, whereas total WU was higher among individuals with high SES, due to a greater consumption of water-intensive PBPs, such as nuts and seeds. These findings highlight socioeconomic disparities in dietary patterns and environmental impact that may be relevant for future strategies toward healthier and more sustainable diets.