Unravelling the association between accelerometer‐derived physical activity and adiposity among preschool children: A systematic review and meta‐analyses

Summary Evidence on the association between physical activity (PA) and adiposity in young children is inconclusive. A systematic review and meta‐analyses were conducted to examine associations between accelerometer‐derived PA and varying adiposity outcomes in preschool children. Searches were conducted in Embase, MEDLINE and Web of Science to identify studies on the association between total PA, sedentary behaviour or different PA intensities and adiposity in children aged 2 to 7 years. Separate random effects meta‐analyses were performed for varying PA intensities and adiposity outcomes. Fifty‐six articles were included in the review and 48 in the meta‐analyses. There was substantial evidence of an inverse association between moderate‐to‐vigorous‐ or vigorous PA and body fat percentage (stdβ [SE] = −0.162[0.041]; 5 studies), weight status (r = −0.120, P<.001; 11 studies), fat mass (stdβ [SE] = −0.103[0.051]; 5 studies), fat mass index (stdβ [SE] = −0.121[0.036]; 2 studies) and skinfold thickness (stdβ [SE] = −0.145[0.036]; 4 studies). However, total PA, sedentary behaviour, and different PA intensities were not associated with body mass index (BMI) or waist circumference. Adiposity levels were lower among preschool children engaged in more (moderate‐to‐) vigorous PA compared with their peers, but no associations between PA and BMI or waist circumference were found.


Web Of Science
TS = (child* OR pediatr* OR paediatr* OR preschool) AND TS = (BMI OR "body mass index" OR overweight OR obes* OR "weight status" OR "body composition" OR "body fat") AND TS = ("physical activ*" OR "physically activ*" OR "activity level*" OR exercis*) AND TS = (accelerom* OR monitor* OR actigraph) Appendix B. QUIPS-based criteria applied in the assessment of the risk of bias.
The 'Quality of prognosis Studies in Systematic Reviews' (QUIPS 2013). QUIPS consists of six domain including the following topics: 1) participation, 2) attrition, 3) determinant measurement, 4) outcome measurement, 5) confounding measurement and account and 6) analysis and reporting. The operationalization of this described in the table below. For all identified articles, each domain will be rated low-, moderate-or high risk of bias by two independent reviewers (RW, BH). Disagreement will be discussed in a consensus meeting or by consulting a third reviewer (EH). The overall percentage agreement and Cohen's kappa will be calculated.
1. Participation a. Description of baseline study sample (at least: age, percentage boys, measure for adiposity) b. Adequate description participant recruitment (how were participants recruited; e.g. well baby clinics, childcare centre or flyers. For which purpose; i.e. if recruited for intervention purposes, then 0) c. Description of period and place of recruitment d. Adequate description of inclusion and exclusion criteria 2. Attrition a. Adequate response rate (Response rate > 80%) b. Reasons for loss to follow-up or loss of (accelerometer) data are provided c. No important differences between participants who completed the study/with accelerometer data and those who did not.
3. Determinant measurement a. Clear definition or description of the determinant provided b. Method of measurement is adequately valid and reliable (at least 3 valid days of 10h /day of PA measurement) 4. Outcome measurement a. Clear definition of the outcome is provided b. Method of outcome measurement used is adequately valid and reliable 5. Confounding measurement and account a. Important confounders are accounted for in the analysis (at least: sex | preferably: SES and nutrition) b. 6. Analysis and reporting a. Sufficient presentation of data b. Selected statistical models is adequate for the design of the study c. No selective reporting of the results

Quips domain
Subdomains 1 Participation a. Description of baseline study sample (at least: age, percentage boys, measure for adiposity) b. Adequate description participant recruitment (how were participants recruited; e.g. well baby clinics, childcare centre or flyers. For which purpose; i.e. if recruited for intervention purposes, then 0) c. Description of period and place of recruitment d. Adequate description of inclusion and exclusion criteria 2 Attrition a. Adequate response rate (Response rate > 80%) b. Reasons for loss to follow-up or loss of (accelerometer) data are provided c. No important differences between participants who completed the study/with accelerometer data and those who did not.  Moderate-to-vigorous physical activity 1) Percentage body fat  [20] β

Confounding
Author, year a.  The results of the subgroup analyses are only shown if results were homogeneous. 2 High prevalence of overweight was defined if >20% of the study sample was overweight/obese. 3 Studies with low risk of bias on this QUIPS item compared to studies with a moderate/high risk of bias.