Pediatric Weight Management

Pediatrics and Physical Activity

Citation:

Abbott, R.A., & Davies, P.S.W. (2004). Habitual physical activity and physical activity intensity: their relation to body composition in 5.0-10.5 year old children. European Journal of Clinical Nutrition, 58, 285-291.

PubMed ID: 14749749
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

Is physical activity associated with lower risk or prevalence of overweight among children?

Combine 2 methods of assessing physical activity and explore the relation between physical activity and body composition in a group of young children, with emphasis on physical activity intensity.

Inclusion Criteria:
Exclusion Criteria:
Description of Study Protocol:

All measurements were made during school term time. A home visit was made to confirm all aspects of the study and obtain written consent from the parents and assent from the child.

Statistical Analysis

Pearson-product moment correlation was used to explore the associated between PAL with percentage of body fat and BMI and spearmans’s rank correlation was used for the association between time spent in intensity of activity with body composition.

A one-way ANOVA was used to explore the relation between tertiles of vigorous activity and hard activity with body composition.

Data Collection Summary:

Timing of Measurements

Dependent Variables

  • Body composition -
  • BMI
  • Height – stadiometer
  • Weight – tanita digital scale

Independent Variables

  • Percentage of body fat (doubly labeled water)
  • PAL – TEE to BMR as measured by DLW
  • PA – tritrac –R3D for 4 days (2 weekdays and 2 weekends)

Control Variables

  • None
Description of Actual Data Sample:

Initial N: 47 children (23 boys, 23 girls) age 5-10.5 years.

Attrition (final N):

Age: 5-10.5 years

 

Summary of Results:

Physical activity level was significantly negatively correlated with both percentage of body fat (r = -.43, p = .002) and with BMI (r = -.45, p = .001).

One-way ANOVA showed there to be a significant differences at the 5% level between PAL tertiles and BMI only. Children in the highest tertile for time spent in hard and above movement had significantly lower percentage body fat levels than those in either the middle (22.7 vs. 29.8%) or the lowest (22.7% vs. 30.5%) tertile.

A greater correlation was found between PAL and body fat in the girls (r = -.39, P = .067) compared with boys.

Intensity of activity was significantly correlated with percentage body fat, but not BMI. Spearman rank correlation analyses showed that vigorous and hard activity were statistically negatively correlated with percentage of body fat with coefficients of r = -.44 (p = .004) and r = -.39 (p = .014).

Author Conclusion:

Body composition as assessed in terms of body fat or BMI was significantly inversely correlated with habitual PA in this study.

The more active the children, the lower their percentage of fat or smaller their BMI.  The most active children, those in the top tertile of PA, had statistically significantly lower BMI scores and lower percentage body fat, than those children in the lowest tertile of PA.

Funding Source:
Government: Australian Govt.
Reviewer Comments:

Limitations:

  • Cross-sectional design limits the ability to determine causality.
  • Accelerometry data was only collected for 4 days
  • Small sample size

Strengths:

Objective measure of PA and use of doubly labeled water.
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) N/A
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? N/A
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? No
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? ???
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? N/A
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? N/A
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? No
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? N/A
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes