Longitudinal Effects of Body Mass Index and Self-Esteem on Adjustment From Early to Late Adolescence: A Latent Growth Model

BACKGROUND: Mental and physical development during adolescence is a factor that may affect quality of life in adulthood. PURPOSE: The aims of this study were to investigate the developmental trajectories of body mass index (BMI), self-esteem, and adjustment among students from early to late adolescence and to examine the longitudinal relationships among these variables. METHODS: Data from 2006 to 2012 were collected from the Korean Welfare Panel Study. Of the initial sample of 521 students, 487 completed a validated questionnaire measuring BMI, self-esteem, and adjustment. Latent growth curve modeling analyses were conducted to examine the relationships among the variables. RESULTS: Univariate linear growth models showed a significant increase in BMI and significant declines in both self-esteem and adjustment across three time points from childhood to adolescence. The goodness of fit of the multivariate conditioned model supported the validity of the proposed longitudinal model (comparative fit index = .93, root mean square error of approximation = .08). Change in BMI was significantly linked with change in adjustment (β = .18, p < .05) but not with change in self-esteem, whereas change in self-esteem exerted a statistically significant effect on change in adjustment (β = .47, p < .001). CONCLUSIONS/IMPLICATIONS FOR PRACTICE: Our findings indicate that BMI and self-esteem are key determinants of student adjustment in school settings. Therefore, future health education interventions should focus on enhancing the positive physical and mental self-concepts of students, which should improve health and social behavior among students and subsequently afford a better quality of life for these students in adulthood.