Ethan T. Hunt

Date of Award

Summer 2021

Document Type

Open Access Dissertation


Exercise Science

First Advisor

Robert G. Weaver


Recent nationally representative data show among children and adolescents aged 2 to 19 years, the prevalence of obesity is 17.0% (95CI= 15.5%-18.6%). Further, rates of obesity are disproportionately high among minoritized youth. The prevalence of children and adolescents with obesity is lower among White children compared to Black children (14.7% vs. 19.5%) or Hispanic children (14.7% vs. 21.9%). Disparities by socioeconomic status exist as well. Prevalence of children with obesity from households with an income that is >350% of the federal poverty threshold (after accounting for household size) is significantly less compared to children from households with an income that is <130% of the federal poverty threshold (10.9% vs 18.9%). Disparities exist by location as well. A recent systematic review concluded that children who reside in rural areas are 2.6 times more likely to have obesity when compared to their urban counterparts. Although children in rural areas have more obesity, this prevalence might differ based on the definition of rural used. Finally, evidence shows children gain 3-5 times the amount of weight and lose cardiorespiratory fitness (CRF) during summer compared to the 9-months of the school year. Notably, this trend is more pronounced in children who are already overweight or obese going into summer and/or from low-income or minoritized households. To our knowledge, no studies have examined summer weight gain by location or rurality status (i.e., exurban vs urban).

The purpose of study 1 was to examine accelerations in body composition (BMI, age-sex specific zBMI, and 95th percentile of BMI [%BMIp95] gain) during the summer months by school locality (i.e., urban, suburban, exurban). This study utilized the Early Childhood Longitudinal Study Kindergarten Class of 2010-2011 (ECLS-K:2011), a complex multistage probability sample from the population of U.S. children who were enrolled to attend kindergarten in the fall of 2010. ECLS-K:2011 data were restricted to those participants with height and weight measured within specific time periods (August/September and April/May) to appropriately examine accelerations in body composition gain during the summer months and school year. A total of 1,549 children (48% female, 42% White) had at least two consecutive measures that occurred in August/September or April/May. Among all locale classifications (i.e., urban, suburban, and exurban), children from high income households comprised the largest proportions for each group (31%, 39%, and 37%) respectively. Among urban and suburban locations, Hispanic children comprised the largest proportions for both groups (43% and 44%) respectively. Among exurban locale classifications, the majority of children were white (60%). Children from suburban and exurban schools experienced significantly less accelerations in monthly zBMI gain compared to their urban counterparts -0.038 (95CI= -0.071, -0.004) and -0.045 (95CI= -0.083, -0.007) respectively. Children from exurban schools experienced significantly less acceleration in monthly %BMIp95 during the summer months when compared to the school year -0.004 (95CI= -0.007, 0.000). This is the first study to examine summer weight gain by school location. Summer appears to impact children more negatively from urban schools when compared to their suburban and exurban counterparts.

The purpose of study 2 of this dissertation is to evaluate children’s proportion of days meeting behavior guidelines: moderate-to-vigorous physical activity (MVPA) ≥60minutes/day, sleep (10-13 hours/night for 5 years, 9-12 hours/night for 6-12 years), and screen-time (<2 hours/day) during the school year compared to summer vacation by race and free/reduced-priced lunch (FRPL) eligibility. Children (n=268, grades=K-4, 44.1%FRPL, 59.0% Black) attending three schools participated. Children’s activity, sleep, and screen-time were collected during an average of 23 school days and 16 days during summer vacation. During school, both children who were White and eligible for FRPL met activity, sleep, and screen-time guidelines on a greater proportion of days when compared to their Black and non-eligible counterparts. Significant differences in changes from school to summer in the proportion of days children met activity (-6.2%, 95CI=-10.1%,-2.3%; OR=0.7, 95CI=0.6, 0.9) and sleep (7.6%, 95CI=2.9%,12.4%; OR=2.1, 95CI=1.4, 3.0) guidelines between children who were Black and White were observed. Differences in changes in activity (-8.5%, 95CI=- 4.9%, -12.1%; OR=1.5, 95CI=1.3, 1.8) were observed between children eligible vs. ineligible for FRPL. Summer vacation may be an important time for targeting activity and screen-time of children who are Black and/or eligible for FRPL.

This complete dissertation works to further the literature exploring childhood obesity, and its behavioral mechanisms that may help to curb prevalence rates that continue to be a public health concern. Obesity prevalence by location has been established in the literature. However, less is known regarding summer weight by school location. Further, I explore the behavioral mechanisms contributing to obesity by examining the proportion of days children meet behavior guidelines during summer vacation and the school year.