Social norms and young adults' self-reported meat and plant-based meal intake: Findings from two online cross-sectional studies.

Plant-based eating is beneficial for human and planetary health. It is important to identify factors which may encourage people to reduce meat, and increase plant-based meal intake. Perceived social norms are associated with meat and plant-based meal intake in adults, however, less is known about the relationship between perceived social norms and young adults' own self-reported meat and plant-based eating in general, and in different social contexts. Across two online studies we examined this. In Study 1 (n = 217 young adults, aged 18-25 years, mean age = 19.50 years, SD = 1.37 years, mean BMI = 24.21, SD = 5.45, 91% cisfemale, 92.0% omnivores), perceived descriptive (the perceived behaviour of others) and injunctive (the perceived approval of others) norms were measured in general. In study 2 (n = 151 young adults aged 18-25 years, mean age = 19.62 years, SD = 1.50 years, mean BMI = 24.32, SD = 4.99, 88.8% cisfemale, 71.1% omnivore), perceived descriptive and injunctive norms were examined in a variety of social contexts. In Study 1, perceived descriptive norms about friends were associated with self-reported meat, and descriptive norms about peers and friends, and injunctive norms about friends were positively associated with self-reported plant-based meal intake. In Study 2, descriptive norms about friends were associated with self-reported meat intake in fast-food restaurants and at friends' houses, and injunctive norms about friends were associated with meat intake in restaurants. There were no other significant associations between either type of social norm and meat or plant-based meal intake. We provide the first evidence that peers and friends may be relevant for plant-based meal intake, and only friends may be relevant for meat intake. Further research is needed to examine people's actual food intake, and in longitudinal studies to rule out reverse causality.