The effect of circadian rhythm and cortisol levels on health nutrition attitudes, emotional eating, and anthropometric measurements in university students

Circadian rhythm, eating attitudes, and stress responses are important determinants of well-being among university students. This study hypothesized that circadian rhythm characteristics would be associated with emotional eating, healthy nutrition attitudes, and salivary cortisol levels. Therefore, this cross-sectional study investigated the associations between chronotype, sleep patterns, eating behaviors, and cortisol concentrations among 213 university students (131 nursing; 82 nutrition and dietetics). Data were collected using the Morningness-Eveningness Questionnaire, the Emotional Eater Questionnaire (EEQ-TR), and the Attitude Scale for Healthy Nutrition (ASHN). Anthropometric measurements were obtained, and salivary cortisol concentrations were analyzed using ELISA. Statistical analyses included Mann-Whitney U, Kruskal-Wallis, and one-way ANOVA tests. The mean salivary cortisol concentration among students was 69.713 ± 3.408 ng/mL. Students reporting lower stress levels exhibited lower cortisol concentrations ( p = 0.025), while cortisol did not differ significantly by gender, department, chronotype, BMI, or exercise status ( p > 0.05). Emotional eating scores were significantly higher among students with intermediate chronotypes and those with irregular or occasionally regular sleep patterns ( p < 0.05), whereas nutrition and dietetics students demonstrated more positive healthy nutrition attitudes than nursing students (75.52 ± 10.80 vs. 70.65± 10.08; p = 0.001). These findings reflect associations rather than causal relationships , and they highlight the relevance of circadian rhythm characteristics and perceived stress in understanding emotional eating tendencies and health-related attitudes among university students. Promoting sleep regularity, stress management, and nutrition education may support healthier behavioral patterns in this population.