Obesity prevention is a public health priority and intervention strategies have focused primarily on healthy eating and physical activity in children and adults. To date, no review has systematically compiled and synthesised the scientific evidence from published review articles to determine whether there is clear consensus on the causes of obesity. A systematic review of the literature was conducted searching PubMed/Medline for narrative and systematic review articles published between January 1990 and October 2014 that examined the causes of obesity. In total, 12 of 65 articles met the inclusion criteria; 7 reviews focused on adults (1 systematic, 6 narrative) and 5 reviews on children (2 systematic, 3 narrative). The most popular cause of obesity identified in reviews of adult studies was “combined physical activity and diet” (3 of 7 studies), whereas the most popular cause specified in reviews of child studies was deemed “inconclusive” (2 of 5 studies). While a number of reviews have examined the causes of obesity, the methodology and conclusions varied widely, and few were conducted systematically. Currently, no consensus exists across published literature reviews regarding the primary cause of the obesity epidemic, and more research, particularly prospective studies using state-of-the-art measures, is warranted.

This study was designed: 1) to describe patterns of age-related change in total and moderate-to-vigorous physical activity (MVPA) in children as they transitioned from elementary school to high school, and 2) to determine if those patterns differed across demographic sub-groups formed on the basis of gender, race/ethnicity, parent education (socioeconomic status), and urbanicity. A cohort of children (analysis sample, N = 951) was comprised of students drawn from two public school districts in South Carolina. Physical activity was measured by accelerometry on at least two and up to five occasions between 2010 and 2017. Growth curve analyses were performed to describe the pattern of age-related change in the physical activity variables for the full sample and for demographic sub-groups. A relatively steep age-related decline in total physical activity was observed in children before age 14, with a slower rate after that age. Physical activity was lower in girls than boys, and the age-related rate of decline was steeper in girls. Physical activity patterns did not differ across race/ethnicity groups, but children of parents with less education were more active than children of parents with more education. Children living in rural areas participated in less MVPA than children living in urban settings, and this difference increased with increasing age. These findings indicate that children experience a particularly steep decrease in physical activity as they transition from elementary to middle school, and this trend is particularly prominent in girls, children living in rural areas, and children of parents with college education.

Latino preschool children have higher rates of obesity than preschool children from other racial/ethnic groups; however, few effective, culturally appropriate interventions exist targeting this group. The purpose of this study was to test the feasibility of a 10-week, promotora-mediated, home-based intervention to promote a healthy weight in Latino preschool children. Trained promotoras (community health workers) delivered 10, 90-min weekly interactive and tailored sessions to Latino families living in Allegheny County. Participants were recruited through promotoras’ own social networks and community gatherings, flyers, and word of mouth. Primary outcome measures included child body mass index (BMI) z-score and percentile. Secondary outcome measures included child objectively measured physical activity and dietary intake, and the home social and physical environment (e.g., parent health behaviors, parent self-efficacy, parental support, physical activity equipment in the home). The final analysis sample included 49 of 51 participants who completed both baseline and follow-up assessments. Participants included mothers (33.5 ± 6.1 years old) and their preschool-aged children who were primarily 1st generation immigrants from Mexico (65%). The primary analyses of BMI percentile and z-score showed no change post-intervention. However, there was a significant decrease in child BMI percentile for overweight and obese children from baseline to follow-up (p < .05). We also saw significant pre/post increases in child daily fruit and vegetable intake, and parent moderate-to-vigorous physical activity, fruit and vegetable servings per day, and self-efficacy; and significant decreases in child saturated fat and added-sugar intake, and child and parent screen time (p’s < .05). Despite the short duration of the intervention and follow-up, this pilot study showed promising effects of a promotora-mediated intervention to promote a healthy weight in Latino preschool children.

Objectives: This study examined the longitudinal associations of objectively measured physical activity, sedentary behavior, and diet quality with two measures of adiposity and a measure of weight status. Methods: A total of 658 children from 21 elementary schools (45.1% boys; 40% white, 33% black, 9% Hispanic, and 18% other race/ethnicity) were assessed at least twice in fifth, sixth, and/or seventh grade. Fat mass index (FMI), percent body fat (PBF), and BMI were calculated from body weight, standing and seated heights, and bioelectrical impedance (BIA) measured each year. Results: At follow-up, both FMI and PBF decreased among boys and increased among girls, while BMI increased in both boys and girls. After controlling for race/ethnicity, parent education, and maturity offset at baseline, growth curve analyses showed that moderate-to-vigorous physical activity (MVPA) was significantly and negatively associated with FMI, PBF, and BMI for both boys and girls. After forming tertiles of fifth grade MVPA, least-square means for FMI, PBF, and BMI were examined by grade and gender. For both boys and girls, higher MVPA was associated with lower FMI, PBF, and BMI at all three grade levels. The relationships between sedentary behavior and diet quality and FMI, PBF, and BMI were not consistent for boys or girls. Conclusions: As boys and girls transitioned from elementary to middle school, children who participated in higher levels of MVPA maintained more favorable levels of two indicators of adiposity and a measure of weight status. These findings support the need for interventions to help children meet current public health guidelines for physical activity.

Physical activity perceptions, context, barriers, and facilitators from a Hispanic child’s perspective