Psychosocial and Behavioral Mediators of Weight Status Among Early Adolescents in the CATCH Cohort

The purpose of this study is to identify psychosocial and behavioral mediators of overweight status among adolescents and investigate variation by gender. Students (n=3,636) participating in the Child and Adolescent Trial for Cardiovascular Health, an epidemiological study of cardiovascular health, were from 96 schools in California, Louisiana, Minnesota, and Texas. Measurements included height and weight, physical activity (PA), minutes spent watching television, and dietary and PA psychosocial measures (intention, self-efficacy, etc.). Psychosocial measures were assessed during 7th grade, while BMI was measured during 8th grade. Weight status distribution of the cohort: 16.9% at-risk (85th% BMI<95th%); 14.5% overweight (95th+%BMI). Structural equation modeling (using MPLUS) with dependent variable weight status (based upon BMI) revealed significant, robust models for both genders. Model fit indicators were CFI=95.5, TLI=.84 and RMSEA=.027 (for boys), and CFI=.98, TLI=.95, and RMSEA= .017 (for girls). Dietary intention (DI) was the strongest predictor of weight status for both genders. Among boys and girls the relationships between dietary knowledge, dietary self-efficacy, dietary social support, positive support for PA and television minutes were mediated by DI onto weight status. For boys, significant paths to minutes of PA were found for PA positive support and dietary social support. Among girls, self-efficacy for PA was the only significant path to PA. Interestingly, a significant, direct path to weight status was found for PA self-efficacy among both genders. These results provide a rationale for targeting psychosocial variables, intentions, and television viewing to change dietary and physical activity behavior, and lead to a change in adiposity.