Young male and highly physically active university students have higher animal-sourced protein intake and greenhouse gas emissions

Introduction: One of the proposed strategies for supporting food system sustainability is replacing animal-sourced protein with plant-sourced proteins since it may result in a significant reduction in land use and greenhouse gas emissions. This study aimed to assess the difference in characteristics of university students regarding their low or high intake of animal-sourced and plant-sourced protein.
Methods: Students at the University of Rijeka, Croatia aged 19 to 27 years (N=224, 46% females, 53% junior) noted sociodemographic data and dietary intake. Anthropometric and body composition parameters were measured. The diet sustainability was assessed through the Planetary Heath Diet Index (PHDI). Greenhouse gas emissions (GHGE) data were obtained from the literature with the SU-EAT method. Students were divided into two groups: high animal-sourced/low plant-sourced protein intake (HAP/LPP) (N=36, 16%), and low animal-sourced/high plant-sourced protein intake (LAP/HPP) (N=34, 15%), based on intake quartiles. The chi-square test was used for testing the difference between groups differences, while logistic regression to assess the odds for high animal-sourced protein intake.
Results: The LAP/HPP intake group consisted of significantly more females (59% vs 25%; p=0.004), and moderately physically active students (54% vs 31%; p=0.004), and had higher PDHI scores (62.21 vs 51.53; p<0.001) and lower GHGE (1.82 vs 2.57 kg CO2/1000 kcal; p<0.001), compared to the HAP/LPP group. Age (p=0.216), university degree (p=0.836), BMI (p=0.069), nutritional (p=0.345) and smoking status (p=0.885) did not differ significantly between groups. Significant higher odds for higher animal-sourced protein intake were male sex (OR=16.40, p<0.001) and high physical activity (OR=3.46, p=0.005). Students with higher animal-sourced protein intake had five-times-higher chances of higher GHGE than those with higher plant-sourced protein intake (OR=4.83, p=0.002).
Conclusions: A healthy and sustainable diet education specifically targeting male and physically active students by strengthening their knowledge and skills in choosing and preparing food with plant-sourced proteins.