Pediatric Weight Management

PWM: Eating Behaviors of Children (2006)

Citation:

Wolfe WS, Campbell CC, Frongillo EA, Haas JD, Melnik TA. Overweight schoolchildren in New York State: Prevalence and characteristics. Am J Pub Health 1994;84:807-813.

PubMed ID: 8179053
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Negative NEGATIVE: See Quality Criteria Checklist below.
Research Purpose:

To determine the prevalence of overweight in elementary school children in New York State and to identify characteristics associated with child fatness.

Inclusion Criteria:
Exclusion Criteria:
None reported.
Description of Study Protocol:

Weight, height, triceps skinfold, midarm circumference, and a 24-hour dietary recall were taken on 1797 second- and fifth-grade students from 51 randomly selected schools in New York State outside of New York City. Parents completed a brief questionnaire.

Statistical analyses:

  • Multiple regression analysis - (to identify factors characterizing fatter from leaner children) after adjustment for possible confounding effects.
  • Chi-square tests with no adjustment for potential confounding factors.

 

Data Collection Summary:

Variables

Independent:

  • Sociodemographic variables-family structure
  • school lunch participation
  • number of siblings
  • maternal employment
  • diet indices (food diversity, skipping breakfast, no vegetables except potatoes and tomato sauce, number of snack foods, and comparison to food groups in Food Guide Pyramid)

Dependent:

  • child fatness (>90th percentile)
  • Body composition - (body mass index, triceps skinfold, arm fat) to measure child fatness; test-retest reliabilities range=97%-100; inter-observer reliabilities = 93%-100%. Reference data from both the National Health and Nutrition Examination Surveys (NHANES I and II) were used for comparison purposes in determining overweight prevalence estimates.
  • Dietary indices -one 24-hour food recall and question about skipping breakfast.
  • Five diet quality indices were developed from the recall:
    • food diversity—number of different foods eaten
    • skipping of breakfast
    • consumption of no vegetable other than potatoes or tomato sauce
    • number of snack foods eaten
    • food group pattern score (“poor” defined as missing one or more of the four food groups or consuming two or more groups only one time each).
  • Children who skipped breakfast were asked whether this was typical; most said it was.
  • Demographics - parent questionnaire. Questions on single or dual parent family, parents’ employment status, school lunch participation, and number of siblings. Children classified as low socioeconomic status (SES) if they met at least one of the following: no parent working, eligibility for free or reduced-price lunches, or receipt of social or food assistance.

Confounding:

  • height,
  • grade,
  • age within grade,
  • sex,
  • race (white or African American),
  • SES,
  • family structure,
  • school lunch participation,
  • number of siblings,
  • maternal employment,
  • dietary indices (food diversity, skipping of breakfast, consumption of no vegetable other than potatoes or tomato sauce, number of snack foods eaten, and food group pattern)
Description of Actual Data Sample:

N: 1797 second- and fifth-grade students (900 boys & 897 girls)

Age: 6-12 years old

Ethnicity: white (predominantly) & African-American ethnicity from 51 randomly selected schools

Location: New York

Summary of Results:

Regression analysis indicated that children were significantly more likely to be overweight if they were  members of low socioeconomic status (P<0.05).

Compared with children who did not eat school lunch, children who ate school lunch were about half as likely to be underweight (P<0.05)

There was an inverse relationship between number of children in family and child fatness.

Children with three or more siblings were significantly less likely to be overweight than children with one or two siblings. (P<0.05)

In two-parent families, children who skipped breakfast were almost twice as likely as breakfast eaters to be overweight than those who ate breakfast. (P<0.05)

Author Conclusion:

In this study, there was a positive association between breakfast skipping and body fatness (P<0.05).

The prevalence of overweight among school-aged children in New York State, outside of New York City (14% to 28% depending on the definition) was high (by as much as twice) in comparison with national representative data. Multivariate analysis identified factors potentially related to overweight status in study children.

  • An inverse relationship between SES and child fatness was found.
  • There was an inverse relationship between number of siblings and child fatness. The authors indicated that children that may be at risk of child overweight include children from low SES two-parent households,, those with few or no siblings, those who ate school lunch, and those who skipped breakfast. (The authors’ conclusion regarding overweight and school lunch consumption does not agree with results).

Further research is needed to understand the relationships between the sociodemographic characteristics and overweight status of elementary school aged children in New York State in order to target preventive efforts.

Funding Source:
Government: New York State Dept. of Health, NIH
Reviewer Comments:

Weaknesses:

  • Cross-sectional study design does not allow for cause and effect inferences.
  • Because study was done with school children in New York, may have limited generalizability to other parts of the country.
  • Failure to measure physical activity.
  • One 24-hour recall
  • Definition of snack foods not described
  • Prevalence of overweight varied with reference data used for comparison.
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) N/A
 
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? No
  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? 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? N/A
  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? No
  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? N/A
  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? Yes
  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? 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)? 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? 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? No
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