Impact of a year-round school calendar on children's BMI and fitness: Final outcomes from a natural experiment

A multivariate multilevel approach to unravel the associations between individual and school factors on children's motor performance in the REACT project

OBJECTIVE

The aim was to (1) estimate the relationship between physical fitness (PF) and object control fundamental movement skills (FMS), (2) identify child characteristics that relate with PF and FMS, and (3) examine associations between the school environment, PF, and FMS.

METHODS

The sample included 1014 Portuguese children aged 6-10 years from the REACT project. PF was assessed via running speed, shuttle run, standing long jump, handgrip, and the PACER test. Object control FMS were assessed with stationary dribble, kick, catch, overhand throw, and underhand roll. Test performances were transformed into z-scores, and their sum was expressed as overall PF and FMS. Child-level variables included body mass index (BMI) z-scores, accelerometer-measured sedentary time and moderate-to-vigorous physical activity, and socioeconomic status (SES). School size, physical education classes, practice areas, and equipment were also assessed.

RESULTS

Approximately, 90% of the variance in object control PF and FMS was at the child level, and 10% at the school level. The correlation between PF and object control FMS was .62, which declined to .43 with the inclusion of covariates. Older, more active, and higher SES children had higher object control PF and FMS, and boys outperformed girls. BMI was negatively associated with PF but not with object control FMS. Sedentary time and number of physical education classes were not significant predictors. Most school predictors did not jointly associate with PF and object control FMS.

CONCLUSION

PF and object control FMS z-scores were moderately related. Not all child characteristics were associated with both PF and object control FMS, and their effect sizes were different. School characteristics only explained 10% of the total variation in PF and object control FMS.

Individual and school correlates of body mass index and cardiorespiratory fitness in primary school children from the REACT project: A multivariate multilevel analysis

OBJECTIVE

This paper examines the relationship between body mass index (BMI) and cardiorespiratory fitness (CRF) using a multivariate multilevel approach and investigates the links between individual and school-related correlates with children's BMI and CRF.

METHODS

This cross-sectional sample included 1014 children (6-10 years) from 25 Portuguese primary schools. BMI was calculated, and CRF was assessed with the PACER test. Fundamental movement skills (FMS) included five object control tasks. Moderate-to-vigorous physical activity (MVPA), sleep, and sedentary time were assessed with the ActiGraph wGT3X-BT accelerometer. Socioeconomic status (SES) and school variables were also obtained. A multivariate multilevel model was used, and alpha was set at 5%.

RESULTS

BMI and CRF systematically increased with age. Most of the joint variance (94.4%) was explained at the child level, and BMI and CRF were correlated at this level (ρ = -.37). More active children demonstrated higher CRF levels and had lower BMI levels; sedentary and sleep time were not significantly associated with BMI or CRF. FMS were positively associated with CRF but were not significantly associated with BMI. Children at higher SES were more fit and had lower BMI than their peers of lower SES. Finally, school-level variables were not significantly related to BMI and CRF.

CONCLUSION

BMI and CRF had a low but statistically significant negative correlation in this sample of children. Most of the variation in BMI and CRF was explained by child-level characteristics.

Depressive Symptoms and Their Longitudinal Impact on Physical Activity and Sedentary Behaviors Among Mexican-Heritage Youth

The purpose of this study is to examine the longitudinal impact of depressive symptoms on physical activity (PA) levels, sedentary behavior, and screen time among first-generation, Mexican-heritage youth. Mexican-heritage families were recruited by promotoras de salud from colonias in Hidalgo County, Texas. Participants (n = 200 youth, 116 families in final sample) completed at-home, interviewer-administered surveys once during the summer (June-July) and once during the fall (August-December). Youth PA and sedentary behaviors were assessed using a validated 7-day recall instrument. The validated Center for Epidemiology Studies-Depression Child scale was used to assess depression symptoms. Linear mixed-effects models were used to analyze the relationships of PA and sedentary behavior with depressive symptoms. Results showed that those depression symptoms were significantly associated with decreased number of self-reported minutes of sitting and screen time over time in the full sample and among male youth. Depression symptoms also significantly decreased the number of self-reported active and moderate to vigorous PA minutes over time among male youth. Researchers can build on our findings by identifying the mechanisms driving the relationships between depression and PA/sedentary behavior. Public health-programing efforts should intentionally consider the impact that depressive symptoms have on PA.

Feasibility and preliminary efficacy of structured programming and a parent intervention to mitigate accelerated summer BMI gain: a pilot study

BACKGROUND

This study assessed the initial feasibility and preliminary efficacy of providing children a free summer day camp and a parent intervention to improve self-regulation and mitigate accelerated summer BMI gain.

METHODS

This pilot 2x2 factorial randomized control trial used a mixed-methods design to evaluate providing children a free summer day camp (SCV), a parent intervention (PI), and the combination of these two strategies (SCV+PI) to mitigate accelerated summer body mass index (BMI) gain. Progression criteria for feasibility and efficacy were assessed to determine if a full-scale trial was warranted. Feasibility criteria included recruitment capability (≥80 participants recruited) retention (≥70% participants retained), compliance (≥80% of participants attending the summer program with children attending ≥60% of program days, and ≥80% of participants completing goal setting calls with ≥60% of weeks syncing their child's Fitbit), and treatment fidelity (≥80% of summer program days delivered for ≥9 h/day, and ≥80% of participant texts delivered). Efficacy criteria were assessed via achieving a clinically meaningful impact on zBMI (i.e., ≥0.15). Changes in BMI were estimated using intent-to-treat and post hoc dose-response analyses via multilevel mixed-effects regressions.

RESULTS

For recruitment, capability and retention progression criteria were met with a total of 89 families participating and 24 participants randomized to the PI group, 21 randomized to the SCV group, 23 randomized to the SCV+PI group, and 21 randomized to the control. However, fidelity and compliance progression criteria were not achieved due to COVID-19 and lack of transportation. Progression criteria for efficacy was also not achieved as intent-to-treat analyses did not show changes in BMI gain that were clinically meaningful. Post hoc dose-response analyses showed that for each day (0 to 29) of summer programming children attended they gained -0.009 (95CI= -0.018, -0.001) less in BMI z score.

CONCLUSIONS

Engagement in both the SCV and PI was not ideal due to COVID-19 and lack of transportation. Providing children with structured summer programming to mitigate accelerated summer BMI gain may be an effective strategy. However, because feasibility and efficacy progression criteria were not met, a larger trial is not warranted until further pilot work is completed to ensure children attend the programming.

TRIAL REGISTRATION

The trial reported herein was prospectively registered at ClinicalTrials.gov. Trial #: NCT04608188.

Seasonal variability in body mass index change among children enrolled in the Pediatric Obesity Weight Evaluation Registry: A step in the right direction

BACKGROUND

Research has shown children disproportionately gain excess weight over the summer months (vs. school months), with stronger effects for children with obesity. However, the question has not been investigated among children receiving care in paediatric weight management (PWM) programs.

OBJECTIVE

To test for seasonal variability in weight change among youth with obesity in PWM care enrolled in the Pediatric Obesity Weight Evaluation Registry (POWER).

METHOD

Longitudinal evaluation of a prospective cohort from 2014 to 2019 among youth in 31 PWM programs. Change in percentage of the 95th percentile for BMI (%BMIp95) was compared by quarter.

RESULTS

Participants (N = 6816) were primarily ages 6-11 (48%), female (54%), 40% non-Hispanic White, 26% Hispanic and 17% Black, and 73% had severe obesity. Children were enrolled on average 424.9 ± 401.5 days. Participants reduced their %BMIp95 every season, but compared with Quarter 3 (July-September), reductions were significantly greater in Q1 (Jan-March, b = -0.27, 95%CI -0.46, -0.09), Q2 (April-June, b = -0.21, CI -0.40, -0.03), and Q4 (October-December, b = -0.44, CI -0.63, -0.26).

CONCLUSION AND RELEVANCE

Across 31 clinics nationwide, children reduced their %BMIp95 every season, but reductions were significantly smaller during the summer quarter. While PWM successfully mitigated excess weight gain during every period, summer remains a high-priority time.

The effect of school year and summer break in health-related cardiorespiratory fitness: A 2-year longitudinal analysis

This study aimed to assess the trends of health-related cardiorespiratory fitness (CRF) during two school years with a 3-month summer break in children and adolescents. A 2-year longitudinal study, including 440 6th to 8th graders (218 boys), mean age 12.3 years, was conducted. The Progressive Aerobic Cardiovascular Endurance Run (PACER) was used to assess CRF. Physical activity was measured using accelerometers. Repeated measures linear models were used to analyses differences and trends in VO2peak and health-related CRF. Overall differences between time-point VO2peak were significant for both boys (p<0.001) and girls (p=0.003). Pairwise comparisons showed that VO2peak improved from the beginning to the end of the same school year for boys (school-year 1: 1.53 ml/kg/min, 95%CI=0.98, 2.09; school-year 2: 1.81 ml/kg/min, 95%CI=1.28, 2.34) and girls (school-year 1: 0.85 ml/kg/min, 95%CI=0.43, 1.27; school-year 2: 1.05 ml/kg/min, 95%CI=0.73, 1.36), while, differences in CRF during summer break were not significant. However, significance was only maintained for girls when performing monthly adjusted analysis. Improvements in CRF were observed during school year and remained unchanged during summer break. These findings provide relevant information for the health education community, suggesting the need for additional efforts to counteract the summer break effects on CRF, especially for girls.

Feasibility &amp; Preliminary Efficacy of Structured Programming and a Parent Intervention to Mitigate Accelerated Summer BMI Gain: A pilot study

BackgroundThis study assessed initial feasibility and preliminary efficacy of providing children a free summer day camp and a parent intervention to improve self-regulation and mitigate accelerated summer BMI gain.MethodsThis pilot 2x2 factorial randomized control trial used a mixed methods design to evaluate providing children a free summer day camp (SCV), a parent intervention (PI), and the combination of these two strategies (SCV + PI) to mitigate accelerated summer body mass index (BMI) gain. Feasibility (i.e., recruitment capability, retention, compliance, treatment fidelity, acceptability) was examined using means, standard deviations, and percentages for relevant variables. Changes in BMI were estimated using intent-to-treat and post-hoc dose response analyses via multilevel mixed effects regressions.ResultsA total of 89 families participated, with 24 participants randomized to the PI group, 21 randomized to the SCV group, 23 randomized to the SCV + PI group, and 21 randomized to the control. Parents and children found the summer program acceptable but attendance at the summer program and engagement in the PI were low due to COVID-19 and lack of transportation. Intent-to-treat analyses showed no statistically significant difference between groups in summer BMI gain. Post-hoc dose response analyses showed that for each day (0 to 29) of summer programming children attended they gained - 0.009 (95CI= -0.018, -0.001) less in BMI z-score.ConclusionsEngagement in both the SCV and PI was not ideal and was likely due to COVID-19 and lack of transportation. Providing children with structured summer programming to mitigate accelerated summer BMI gain may be an effective strategy. Thus, a larger trial may be warranted, but more work is needed to ensure children attend the programming.Trial registration: The trial reported herein was prospectively registered at clinicaltrials.gov. Trial #:NCT04608188.