Pediatric Weight Management

PWM: Foods and Nutrients (2006)


Davies PSW. Diet composition and body mass index in pre-school children. European Journal of Clinical Nutrition 1997; 51: 443-448.

PubMed ID: 9234026
Study Design:
Cross-Sectional Study
D - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To investigate the relationship between diet composition and BMI in pre-school children.

Inclusion Criteria:
  • UK-nationally representative sample
  • Eligibly entailed children between ages 1.5 and 4.5 years.
Exclusion Criteria:

Not specified.

Description of Study Protocol:
  • National Diet and Nutrition Survey (NDNS) required that a nationally representative sample of pre-school children be recruited
  • Sample was selected using a multi-stage random probability design, with postal sector as first stage units. From each postal sector addresses were randomly selected.
  • Only households returning a form with an eligible child were included and only one child per household was selected
  • The parent or caregiver of the child was asked to keep a weighed record of all food and drink consumed by the child, both in and out of the home, over four consecutive days.
Data Collection Summary:
  • Dependent variables: BMI standard deviation scores (SDS) relative to UK reference data (height and weight were recorded were possible)
  • Independent variables: Percent total energy from fat, CHO and protein (also expressed as grams per day) were divided into quintiles (four-day weighed food records completed by parent or caretakers of the child).
  • Control Variables: Age and gender
  • Statistical analysis: ANOVA and multiple regression.


Description of Actual Data Sample:
  • Original sample: Not specified
  • Withdrawals/Drop-outs: Not specified
  • Final sample: 1,444 pre-school children (721 boys, 723 girls)
  • Age: 1.5 to 4.5 years
  • Location: Community based project throughout Great Britain
  • Race/Ethnicity: Nationally representative sample
  • SES: Nationally representative sample.
Summary of Results:
  • No trends that indicated that diet composition was related to body size
  • Analysis of variance: Analysis of variance revealed no difference across quintiles of macronutrient intakes in mean BMI SDS, in either boys or girls
  • Multiple regression: There was no significant association between % energy intake from any nutrient group and BMI SDS.
Author Conclusion:
  • In a large cohort of pre-school children the authors were unable to confirm the recent findings in much smaller samples that diet composition affects body size. Other factors such as energy intake per se and levels of habitual physical activity might have a more important bearing on BMI in pre-school children.
  • It is possible that if diet composition does influence body size there is a time course over which the influence takes place and that the group of children studies here (1.5 to 4.5 years) was too young to reveal such a relationship.
Funding Source:
Government: Ministry of Agriculture, Fisheries and Food (UK), Department of Health
University/Hospital: Queensland University of Technology (Australia), Dunn Nutrition Unit (UK)
Reviewer Comments:

The study did not specify a protocol for children who were still being breastfed.

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? Yes
  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? Yes
3. Were study groups comparable? N/A
  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? N/A
  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? N/A
  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? Yes
  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? Yes
  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? Yes
  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? Yes
  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? N/A
  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? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? No
  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)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
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