Book Description

"Obesogenic food environmental factors are associated with unhealthy dietary intake and obesity among adolescents. Evidence suggests that adverse environmental factors can have a negative effect on executive functioning. The investigation of how the obesogenic food environment influences the development of executive functioning over time remains unexamined. The purpose of this study was to examine the longitudinal effect of obesogenic food environmental factors on body mass index (BMI) and executive functioning among low-income African American adolescents. Analyses were based on four waves of data collected between 1994-2014 from the Memphis New Mothers Study, a longitudinal randomized controlled trial (RCT) of low-SES women and their first-born children's health and overall well-being. Using control group data only, latent growth modeling was used to analyze whether the obesogenic food environment at age 4.5 years is associated with changes in BMI and executive functioning over three time-points and what time-varying and time-invariant variables predict these changes. Growth mixture modeling was used to identify subgroups (classes) based on individual longitudinal trajectories of impulsivity, cognitive inflexibility, and working memory performance in adolescents. In addition, binomial or multinomial regression analyses were performed to investigate the associations between the hypothesized primary predictor (mRFEI) and covariates with the participant trajectory class memberships. Results indicated that maternal smoking and alcohol use during pregnancy was associated with the rate of change over time of impulsivity scores over the 12 years of the study. Prenatal alcohol use during pregnancy was associated with cognitive inflexibility at baseline and from ages 6 to 18. Maternal education at age 6 and neighborhood disorganization at ages 6 and 18 were also associated with cognitive inflexibility. Boys had lower age 6 baseline scores and quicker rates of increased working memory changes than girls. Gestational age was associated with baseline working memory scores. Birth weight was associated with the linear change in working memory, and household income and neighborhood disorganization were also associated with working memory in youth ages 12 and 18. Contrary to the study's hypotheses, the obesogenic food environment at age 4.5 did not explain the variance in boys' and girls' BMI categories, executive functioning at baseline, or variance in change over time for the overall sample. Growth mixture modeling enabled identification of the following distinct trajectory classes of executive functioning: (1) impulsivity: moderate-stable and moderate-increasing; (2) cognitive inflexibility: low-stable, very high-stable, and moderate-stable; (3) working memory: deficient-stable, low-stable, and moderate-stable. For impulsivity, results indicated no significant associations between the chosen predictors or covariates with class membership. For cognitive inflexibility, using the moderate-stable class as the reference group, higher maternal pre-pregnancy BMI was associated with membership in the low-stable and very high-stable classes. Also, neighborhood disorganization was associated with membership of the low-stable cognitive inflexibility class, but not the very high-stable class. For working memory, mRFEI scores were statistically associated with membership in the low-stable working memory class versus the moderate-stable working memory class (reference group), suggesting that working memory trajectories may be negatively affected by early exposure to obesogenic environments. Although obesogenic food environment was associated only with working memory trajectory class membership, other neighborhood indices were associated with specific trajectories in executive functioning, but not children's BMI. Also, maternal behaviors during pregnancy were associated with executive functioning trajectories. To further advance the knowledge and understanding about environmental risk factors on executive functioning in youth, more nuanced measures of obesogenic environment and addition of eating behaviors would be necessary. Nevertheless, the current insights support designing nutritional and cognitive developmental programming and educational interventions to ensure that adolescents receive adequate nutrition for cognitive health."--Pages xvi-xviii.