PWM: Eating Behaviors of Children (2006)

Siega-Riz AM, Carson T, Popkin B. Three squares or mostly snacks – What do teens really eat? A sociodemographic study of meal patterns. J Adolesc Health 1998;22:29-36. PubMed ID: 9436064
Study Design:
Cross-Sectional Study
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To categorize U.S. adolescents’ meal patterns and related differences in dietary quality.

Inclusion Criteria:
Only those who reported all three days of dietary intake.
Exclusion Criteria:
Not specified.
Description of Study Protocol:


  • Not described in this paper.


  • Nationally representative data from 1989-1991 CSFII using a multistage, stratified sample design of the 48 coterminous states and Washington, DC.

Statistical Analysis

  • Sample weights used to allow for generalization to the entire U.S. adolescent population
  • Differences in nutrient intake between meal pattern categories calculated by regressions
  • Multivariate analysis of determinants of meal pattern type using logistic regression techniques; model trimmed by dropping nonsignificant terms (terms not significant:  northeast region, west region, central city residence, female head of household, employment status, household size, supplement use, BMI).
Data Collection Summary:
  • No blinding.

Independent Variables

  • Eating occasion
    • Defined according to name given by respondent: Breakfast, lunch, dinner or snack
    • Supper counted as dinner; if supper and dinner, then dinner counted as lunch
    • Brunch not included because only 1.4% of all eating occasions (do not say if then classified as lunch or breakfast).
  • Meal pattern categories:
    • Consistent: Two or three meals with or without snacks on all three days
    • Moderately consistent: Two or three meals with or without snacks on two of three days
    • Inconsistent: One meal with or without snacks, or snacks only, on all three days.

[Note: One 24-hour recall and two one-day food records by female HOH for children under 12 years of age; meal patterns did not differ between children aged 11 and 12 years.]

Dependent variables

  • Age
  • Gender
  • Ethnicity
  • Region of residence
  • Supplement use
  • School attendance
  • Educational and employment status of female HOH
  • Income status (poverty percentage) of household
  • School-based meal consumption
  • BMI (self-reported weight and height)
  • Single- vs. dual-parent household
  • Nutrient percentage RDA
  • Diet Quality Index Score (DQI) based on eight food- and nutrient-based recommendations from the National Academy of Sciences.

Control variables

  • See above for variables tested, but not included and the results section for ones included in final model.
Description of Actual Data Sample:
  • N: 1,310
  • Age: 11-18 years
  • Ethnicity: Not specified
  • Other demographics: Not specified.
Summary of Results:

Meals Pattern Category

  • Consistent: 41%
  • Moderately consistent: 55.5%
  • Inconsistent: 3.5%
  • Consistent meal pattern in bivariate (no control) analyses had significantly:
    • More male subjects
    • More white subjects
    • More female heads of household who attended college
    • More subjects who attended school
    • More larger households
    • More single-parent households
    • Fewer weight-reducing diets
    • More subjects with lower BMI (20.8 in consistent, 21.5 in moderately consistent, 22.4 in inconsistent; consistent differs from other two (P<0.05)

[Note: Nutrient and food group and DQI analyses also reported in paper.]

Greater Risk of Inconsistent Meal Pattern (in multivariate analysis)

[Note: BMI did not remain in final model.]

  • Older (15-18 years of age)
  • Male
  • Black
  • Single-parent household
  • Not attending school
  • Not consuming school breakfast
  • Not consuming school lunch
  • Less than 185% of poverty.
[Note: ORs and 95% CIs in Table Four.]
Author Conclusion:

Adolescents who consume at least two meals (with or without snacks) on a consistent basis have an adequate intake of calories and a more nutrient-dense diet with respect to calcium, iron, vitamin E and fiber than those with other meal patterns. From the perspective of following a diet to prevent chronic diseases in adulthood, adolescents regardless of meal pattern, consume a diet that is too high in fat, sodium and protein and too low in fiber.

We need to understand how adolescents define a meal and a snack. Another issue to consider is how meal patterning affects obesity, if at all. Do inconsistent meal patterns increase the likelihood of being obese or is there a set of factors that affect both meal pattern choices and the constellation of factors that contribute to obesity? Further research is needed to explore these topics.

Funding Source:
Reviewer Comments:


  • Large sample size
  • Nationally representative
  • Control for several confounders
  • Described how defined eating occasions.


  • Self-reported weight and height
  • Not clear how or why study used meal pattern categories.
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? 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? No
  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? No
  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? No
  7.5. Was the measurement of effect at an appropriate level of precision? No
  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? Yes
10. Is bias due to study's funding or sponsorship unlikely? No
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? No