Food insecurity and childhood obesity are both major public health concerns in the United States of America. Research has not found a definite relationship between childhood obesity and food insecurity to date, with conflicting results being found due to differences in sample sizes and protocol for measuring key variables. Preschoolers (children aged 2-5 years) are a population of particular interest as there tends to be improved health behaviors and greater adaptability to change at this period of growth and development. This study aims to evaluate if there is a relationship between food insecurity and childhood obesity with diet quality as a mediator among preschoolers in the Phoenix area. A secondary data analysis from participants (n=154) from the SAGE (Sustainability via Active Garden Education) research project was used to evaluate food insecurity status, diet quality components (kcal, saturated fat, added sugars, and servings of juice, fruits, and vegetables), and anthropometrics (waist circumference and BMI percentile). No significant associations between food insecurity status, diet quality components, and anthropometric data were found. There was an increased rate of food insecurity and childhood overweight/obesity in this sample compared to state and national averages. Further research of high quality is necessary to determine whether a relationship exists between childhood obesity and food insecurity exists and in what context. Additionally, practice and policy will need to be implemented to decrease rates of food insecurity and childhood obesity among Phoenix preschoolers.

Background. Street food stands (SFS) are common ways in which people in Mexico access food, having been a part of the environment and culture of Mexican food for generations. However, no studies have used a validated assessment tool to reliably measure food and beverage availability at a variety of SFS. Nor have the availability, density, variety, and distribution of SFS and street foods and beverages been assessed across neighborhood income levels.Objective: This dissertation’s goal was to decrease gaps in knowledge about the role SFS may play in food availability in the Mexican food environment.
Methods: Survey design and ethnographic field methods were used to develop, test, and validate the Street Food Stand Assessment Tool (SFSAT). Geographic information system and ground-truthing methods were used to identify a sample of street segments across 20 neighborhoods representing low-, middle- and high-income neighborhoods in Mexico City on which to assess the availability, density, variety, and distribution of SFS and the foods and beverages sold at these food venues using the SFSAT.
Results: A sample of 391 SFS were assessed across 791 street segments. Results showed that SFS were found in all neighborhoods. Contrary to the initial hypothesis, most SFS were found in middle-income neighborhoods. While the availability of street foods and beverages was higher in middle-income neighborhoods, the variety was less consistent: fruit/vegetable variety was high in high-income neighborhoods whereas processed snack variety was higher in low-income neighborhoods. SFS were most often distributed near homes, transportation centers, and worksites across the three neighborhood income levels.
Conclusion: This study bridged the gap in knowledge about the availability, density, variety, and distribution of SFS and products sold at these sources of food by using an assessment tool that was developed, tested, and validated specifically for SFS. The findings showed that SFS were found across all neighborhoods. Furthermore, results also suggested that SFS can be a source of healthy food items. Additional studies are needed to understand the relationship between SFS availability, food consumption, and health outcomes in the Mexican population.

This body of research sought to explore relationships between cognitive function and physical activity (PA), sedentary behavior (SB), and sleep, independently and in conjunction, in mid-life to older adults with no known cognitive impairment. Aging is associated with cognitive decline, and lifestyle behaviors such as PA, SB, and sleep, may mitigate this decline. First, a systematic review and meta-analysis was conducted to examine the effect of aerobic PA interventions on memory and executive function in sedentary adults. Second, a longitudinal study was conducted to examine the association between SB and odds of incident cognitive impairment, and SB and cognitive decline in older adults. Last, a cross-sectional study was conducted to examine the joint associations between different levels of sleep with levels of PA, and sleep with levels of sedentary time on memory and executive function. This body of research provided evidence to support the association between aerobic PA and improved cognitive function, SB and incident cognitive impairment and cognitive function declines, and the joint association of sleep and different levels of PA and ST on cognitive function by hypertension status.

This dissertation was guided by the Ecological Model of Physical Activity and Ecological Model of Obesity and sought to determine the relationship between active transportation (AT), physical activity, and cardiometabolic health among adults and ethnic minority women. Chapter 2 presents an investigation into the relationship between walking for AT and cardiometabolic health among adults through systematic review. Chapter 3 presents an exploration of the cross-sectional relationships of AT and moderate-to-vigorous physical activity (MVPA) with cardiometabolic health among African American (AA) and Hispanic/Latina (HL) women from Texas. Chapter 4 presents an investigation into the cross-sectional relationship of AT on cardiometabolic health and physical activity among primarily HL women.

In Chapter 2, walking for AT was found to be related to smaller waist circumference, lower blood pressure, and lower prevalence of abdominal obesity and hypertension, and that differences may exist based on sex. Walking for AT was not clearly defined, and criteria used to determine the presence of cardiometabolic outcomes were inconsistent. No significant relationships between AT and cardiometabolic health were found in Chapter 3 or 4; however, AT users had slightly better cardiometabolic health. AT users had significantly higher levels of self-reported total physical activity compared to those who did not use AT in Chapter 3. Furthermore, a significant relationship was found between MVPA and diastolic blood pressure. Associations differed by ethnicity, with MVPA being inversely related to body fat in both AA and HL women, but to body mass index only in AA women. AT users were found to be seven times more likely to meet 2018 national MVPA recommendations than non-AT users in Chapter 4. Across all studies, measures of AT were subjective and of low quality, potentially limiting the ability to detect significant findings.

High quality randomized controlled studies should be conducted using clearly defined, objective measures of AT, and analyzed based on sex and race/ethnicity. Clinicians should recommend AT use to promote meeting MVPA recommendations where appropriate, potentially resulting in improved cardiometabolic health. Policymakers should advocate for changes to the built environment to encourage AT use and MVPA to improve public health.

Through three investigations, this dissertation examined properties of the family and early care and education center (ECEC) environments related to preschool-aged children’s cardiovascular fitness (CVF) and gross locomotor skills (GLS). Investigation one used a systematic review and meta-analysis to synthesize the effectiveness of school-based interventions at improving CVF, in preschool-aged children. For investigations two and three product- and process-based measures of GLS were collected from children in ECECs (n=16), using the progressive aerobic cardiovascular endurance run (PACER; n=144) and the CHAMPS motor skill protocol (CMSP; n=91), respectively. Investigation two and three examined family factors and ECEC factors for associations with measures of GLS, respectively.

Investigation one revealed a moderate-to-large effect size for school-based interventions (n=10) increasing CVF (g=0.75; 95%CI [0.40-1.11]). Multi-level interventions (g=.79 [0.34-1.25]) were more effective than interventions focused on the individual (g=0.67 [0.12-1.22]). In investigations two and three children (78.3% Hispanic; mean ± SD age 53.2±4.5 months) completed a mean ± SD 3.7±2.3 PACER laps and 19.0±5.5 CSMP criteria. Individual and family factors associated with PACER laps included child sex (B=-0.96, p=0.03) and age (B=0.17, p<0.01), parents’ promotion of inactivity (B=0.66, p=0.08) and screen time (B=0.65, p=0.05), and parents’ concern for child’s safety during physical activity (B=-0.36, p=0.09). Child age (B=0.47, p<0.01) and parent employment (B=2.29, p=0.07) were associated with CMSP criteria. At the ECEC level, policy environment quality (B=-0.17; p=0.01) was significantly associated with number of PACER laps completed. Outdoor play environment quality (B=0.18; p=0.03), outdoor play equipment total (B=0.32; p<0.01) and screen time environment quality (B=0.60; p=0.02) were significantly associated with CMSP criteria. Researchers, ECEC teachers and policy makers should promote positive environmental changes to preschool-aged children’s family and ECEC environments, as these environments have the potential to improve CVF and GLS more than programs focused on the child alone.

This body of research sought to explore relationships between parenting practices, physical activity resources, and Hispanic children’s physical activity. Guided by the Family Ecological Model (FEM) and the Ecological Model of Physical Activity (EMPA) this study examined the influence of parents on children’s physical activity through an integrative review. A cross sectional study was conducted to investigate potential relationships between parental perception safety at school, gender, and children’s physical activity. A cross sectional study was also utilized to examine potential correlations between parenting practices, physical activity resources, and children’s physical activity. Parental role modeling of physical activity and parental support for physical activity emerged as parenting practices that have considerable potential to impact children’s physical activity. Gender differences among children’s physical activity were also a key finding of this study with boys participating in more physical activity than boys. While quality of physical activity resources did not have significant associations with parenting practices or children’s physical activity, more research is needed to determine how resources for physical activity may impact parenting practices, and children’s physical activity.