Carbon Footprint of Animal- and Plant-Based Protein Foods Consumption Among Adults in Saudi Arabia

Background/Objectives: Animal-source protein consumption in Saudi Arabia has increased substantially over the last two decades, raising concerns regarding its environmental impact in a country with among the highest per capita carbon emissions globally. Despite growing interest in sustainable diets, empirical evidence on dietary carbon footprint (CF) in Gulf Cooperation Council countries remains limited. This study aimed to quantify the CF associated with the consumption of animal- and plant-based protein foods among Saudi adults and to identify sociodemographic and lifestyle predictors of dietary CF, with attention to sex differences. Methods: A cross-sectional study was conducted among 1624 Saudi adults (47.1% males; 52.9% females). A newly developed, expert-reviewed, and pilot-tested food frequency questionnaire covering 21 protein-containing food items (13 animal-based; 8 plant-based) was used to estimate daily intake. CF values were calculated using Life Cycle Assessment-derived greenhouse gas emission factors (kgCO2e/kg food) obtained from peer-reviewed sources. Sex-stratified multiple linear regression models and a pooled sex × animal-source protein food interaction model was used to identify independent predictors of daily CF. Results: Animal-source protein foods contributed 45,641.8 kgCO2e/week to cumulative CF—a 64-fold excess over plant-based sources (708.33 kgCO2e/week). Mean individual protein-food CF was 4.07 kgCO2e/day, of which 98.5% derived from animal sources. Lamb and beef carried the highest emission intensities; nuts the lowest. Animal-source intake was the strongest independent predictor of CF in both sexes, with a significantly stronger association in males than females. High consumers substantially exceeded EAT–Lancet red meat targets across all consumption strata. Conclusions: Red meat dominates protein-food-related GHG emissions among Saudi adults. Even a partial dietary shift toward plant-based proteins, embedded within a coordinated food-system transformation framework, could substantially reduce per capita emissions in alignment with Saudi Vision 2030 and One Health targets.