Pediatric Weight Management

PWM: Family Influences (2006)

Citation:

Johnson SL, Birch LL. Parents’ and children’s adiposity and eating style. Pediatrics 1994; 94: 653-661.

PubMed ID: 7936891
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To examine the data for any relations that might exist between the following:

  • Children’s eating index and children’s anthropometric measures
  • Parents’ weight status and parental dieting history
  • Parents’ and children’s eating styles
  • Parents’ child-feeding practices and children’s eating index.

Relations that might indicate the existence of parental influence on children’s eating styles and weight outcomes.

Inclusion Criteria:

Age-eligible children who attended a university preschool setting (Urbana, IL) with parents born in the US.

Exclusion Criteria:
Children with inability to consume the entire drink load.
Description of Study Protocol:
  • Children participated in one pair of calorie compensation trials during which they were asked to drink high- or low-calorie fruit-flavored drinks that differed only in carbohydrate and therefore calorie content
  • After a short interval, children ate lunch ad libitum and their responsiveness to the energy density differences of the drinks was assessed by measuring energy consumption during lunch.

Statistical Analysis

  • Descriptive statistics: Means, standard errors, ranges, skewness, kurtosis and Wilk's test of nomality
  • Gender differences were assessed using T-tests
  • Correlation and multivariate regression analyses.
Data Collection Summary:
  • Dependent variables: Children’s eating index (% compensation – COMPX)
  • Independent variables:
    • Children’s adiposity: Measured height and weight and skinfolds
    • Parent’s dietary restraint, disinhibition, and perceived hunger: Stunkard and Messick’s Three-Factor Eating Questionnaire
    • Parental control over child’s feeding: Child-Feeding Questionnaire
    • Parental BMI (self-reported).
  • Control variables: Gender.
Description of Actual Data Sample:
  • N: 77 (46 girls, 31 boys)
  • Age: Three to five year old children
  • SES: Predominantly middle class
  • Ethnicity: Predominantly White (five African American, nine Asian)
  • Location: Urbana, IL.
Summary of Results:
  • Children who compensated poorly, that is, eat less lunch following the snack-drink were in fact significantly fatter (P<0.006) 
  • Girls’ COMPX was significantly negatively correlated with their anthropometric measures – fatter girls were less likely to compensate. For boys, only weight and weight/height correlated significantly and positively with COMPX.  Boys overall compensated better than girls.

Parental Factors

  • Heavier parents reported a higher incidence of disinhibited eating, which refers to a tendency to eat uncontrollably even when not hungry
  • Highly controlling parents had children who showed less evidence of self-regulation of caloric intake
  • Parental disinhibition was negatively correlated to their children’s ability to regulate energy intake (r=-0.35, P<0.02)
  • No correlation between parental dietary restraint and children’s COMPX emerged. However, mothers’ dietary restraint was marginally negatively correlated with girls’ COMPX (r=-0.37, P<0.08). Boys’ COMPX and mother’s restraint were significantly positively correlated (r=0.41, P<0.05).
  • Multiple Linear Regression: Parental control index was negatively associated with children’s eating index. Gender was a significant covariate – reveals that girls and boys may be parented differently in the feeding context. 
Author Conclusion:
  • The findings suggest that parental control in the feeding context is an important predictor of children’s responsiveness to energy density and of their weight outcome
  • The optimal environment for children's development of self-control of energy intake is that in which parents provide healthy food choices, but allow children to assume control of how much they consume  
  • Sex differences in the control of food intake are present as early as the preschool period and that from a very early age, males and females are socialized differently regarding food and eating.
Funding Source:
Government: NIH
University/Hospital: University of Illinois
Reviewer Comments:

Strengths:

  • Investigators and classroom personnel were blinded to the experimental condition (high-calorie vs. low-calorie fruit drink)
  • While the outcome measure was not a measure of child adiposity; child adiposity was measured and was indirectly explained by both parental dietary disinhibition and restraint as well as parental child feeding practices.
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) Yes
  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? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) ???
  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.) No
  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? Yes
  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%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  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? No
  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.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  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? Yes
  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? Yes
  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)? ???
  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? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes