Sex-Based Differences in Lifestyle Behaviours, Self-Esteem, and Academic Performance: A Structural Equation Model in High-Socioeconomic-Status School-Aged Youth from Southern Spain

Abstract

Objectives: The present study aimed to examine the relationships between screen time (ST), sleep time (SLT), physical activity engagement (PA), Mediterranean diet (MD) adherence, body mass index (BMI), self-esteem (SE) and academic performance (AP) in high-socioeconomic-status (SES) school-aged youth in southern Spain. Methods: A descriptive, comparative, non-experimental and cross-sectional research study was conducted with a total sample of 217 Spanish students (13.88 ± 1.32). Structural equation modelling (SEM) was employed to analyse relationships between study variables as a function of sex. Results: SLT was positively associated with MD adherence and negatively related with BMI. Both PA and MD adherence were positively linked to SE, whilst MD adherence and SE were also positively related to AP. Regarding sex differences, ST was a stronger determinant among girls, showing negative associations with PA (β = −0.378; p < 0.001) and MD adherence (β = −0.315; p < 0.001), with this pattern not being observed in boys. PA was positively associated with SE in both sexes, but more strongly in boys (β = 0.332; p < 0.001) than in girls (β = 0.190; p = 0.034). In girls, both MD adherence (β = 0.295; p < 0.001) and SE (β = 0.224; p = 0.008) were positively associated with AP, with these associations not being found in boys. Conclusions: The findings underscore the complex interplay between lifestyle behaviours, psychosocial factors, and AP in school-aged youth. Regardless of SES, interventions should focus on reducing ST, promoting PA and MD adherence, and enhancing SE whilst considering sex-specific patterns.