Prospective Associations Between Executive Function and Obesogenic Behavioral Trajectories from 4th through 6th Grade

Introduction:Growing evidence suggests that impairments in children’s executive function (EF) may result in increased obesogenic behavior, contributing to the present obesity epidemic.  However, little work to date has utilized a longitudinal approach which can take into account how relationships between EF, sedentary behavior, and consumption of high-calorie/low-nutrient “junk” foods may vary across development and be influenced by time-varying covariates such as perceived stress, which has been linked to both junk food intake and EF. 

Methods: Data were collected from 709 participants in the school-based Pathways to Health prevention trial followed from 4^th through 6^thgrade.  A self-report survey included items taken from the inhibitory control, emotional control, working memory, and organization of materials subscales of the Behavioral Rating Inventory of Executive Function.  Sedentary behavior and junk food intake were assessed via validated open-source questionnaire items.  Perceived stress was assessed via a short-form of the Cohen perceived stress scale. Each variable was continuous. A multivariate linear growth curve model (CFI=.95; RMSEA=.04) was fit for parallel processes of executive function, junk food intake, and sedentary behavior, each of which was assessed at 4 time points.  Regression coefficients were estimated between all random slopes and intercepts adjusting for gender, Hispanic ethnicity, White ethnicity, SES, program vs. control group assignment, and student clustering by school.  Stress was included as a time-varying covariate at each time point.   

Results:  At fourth grade, EF impairment was associated with greater sedentary behavior (p<.001) junk food intake (p<.01), and perceived stress (p<.001).  Furthermore, increased EF impairment from 4^th to 6^th grade was associated with increased sedentary behavior (p<.001), and junk food intake (p<.05) over time.  Stress was highly associated with EF impairment at each assessment wave (p<.001).  Sedentary behavior and junk food intake were also significantly associated at fourth grade (p<.001) and from 4^th-6^th grade (p<.001).  Low income students consumed more junk food (p<.001), were more sedentary at fourth grade (p<.05) and showed greater increases in sedentary behavior from 4^th to 6^thgrade (p<.05) compared to students who were not eligible for the federal free lunch program.  Hispanic students also consumed more junk food at fourth grade (p<.01) and showed greater increases in their sedentary behavioral trajectories compared to non-Hispanic students (p<.05). 

Conclusions: Efforts to reduce stress and promote EF, particularly among low-income and Hispanic schoolchildren, may reduce obesogenic behavior during the late-elementary school years.