PWM: Family Influences (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To evaluate the relation between mothers' child-feeding practices and children's adiposity in a sample of boys and girls from 2 ethnic groups.
Inclusion Criteria:

Subjects were from an ongoing, longitudinal study of childhood obesity.

Exclusion Criteria:

Absence of major illness since birth.

Description of Study Protocol:

The sample included both obese and normal-weight children. Percent overweight was not specified.

Dietary Data and Feeding Practices

Dietary data collected from the children during an overnight visit to the General Clinical Research Center (GCRC) at the University of Alabama at Birmingham. While the children were at the GCRC for testing, the mothers participated in a brief, in-person interview asking about their feeding practices. Mother's feeding practices were measured by using 5 subscales from the Child Feeding Questionnaire.

Two weeks after the GCRC visit, the children completed further testing at the Department of Nutrition Science at the University of Alabama at Birmingham clinic, including assessment of body composition by DXA (with the children arriving in the fasted state).

Child Feeding Questionnaire:

The CFQ includes five subscales:

Mother's monitoring of food intake: This measure examines the degree to which a mother keeps track of her child's consumption of sweets, snack foods, and high-fat foods. 

Responsibility for feeding: This item measures how responsible the mother feels for feeding her child, determining portion sizes, and providing a healthy diet.

Food restriction: This measure examines the mother's attempts to control her child's eating by restricting access to palatable foods. It concerns the restriction of both the type and amount of food. Restriction of food by mothers was previously shown to be related to both daughters' daily energy intake and short-term ability to control energy intake.

Pressure to eat: This measures the degree to which the mother encourages the child to eat by behaviors such as insisting that the child eat everything on his or her plate. 

Concerns for child's weight: This items examines the degree to which the mother is concerned that her child is or will become overweight and be forced to diet. 

Statistical analyses:

2X2 univariate factorial analyses of variance (to explore any influences of sex and ethnicity on the control variables and on total fat mass and whether mothers’ child-feeding practices differed according to the children’s sex, ethnicity, or both). Partial correlations (adjusting for weight concern between the child-feeding practice subscales and total fat mass). Multiple regression analysis (adjusting for confounders to determine extent to which variance in total fat mass could be explained by child feeding practices).

Data Collection Summary:

Independent

  • mother’s child feeding practices

Dependent

  • children’s adiposity
  • Body composition
  • total fat mass (dual energy X-ray absorptiometry).
  • Dietary intake –
    • 3, 24-hour recalls using the multiple pass technique; average of 3 for analysis
  • Child-feeding practices –
    • 5-subscales from the Child Feeding Questionnaire (reliability with Cronbach’s a=0.72-0.78)
  • Mother’s monitoring of food intake
    • Responsibility for feeding
    • Food restriction
    • Pressure to eat
    • Concern’s for child’s weight
  • Socioeconomic status
  • Use of Hollingshead 4-factor index of social class

Confounding

  • Total lean mass,
  • sex, ethnicity,
  • SES,
  • energy intake,
  • energy intake from sources other than fat.

Assessed the effect of energy intake from fat on total fat mass and the effect of energy intake from sources other than fat on total fat mass separately.

Description of Actual Data Sample:

Sample: 74 white (25 boys & 49 girls) and 46 African- American (22 boys & 24 girls)

Age: children aged 7-14 years old, and their mothers.

Ethnicity: white and black

Location: Birmingham, Alabama

 

Summary of Results:

Mother Feeding Practices and Total Fat Mass

Multiple regression showed the results from 2 subscales- mother’s concern about child’s weight and pressure to eat (P=0.001 and P=0.03, respectively), explained 15% of variance in total fat after adjusting for total lean mass and energy intake (sex, ethnicity, dietary fat, and socioeconomic status failed to account for any variance in total fat mass) .

The following variables were not associated with total fat mass:

  • Food restriction
  • Monitoring of food intake
  • Mother responsibility for child's intake

Energy from sources other than fat explained 5% of the variance in total fat mass after adjusting for confounders (total lean mass and energy intake) (P=0.04).

Cross-sectional:

Concern for child’s weight was positively related to total fat mass (P<0.001) whereas pressure to eat was negatively related to total fat mass (P<0.01).

 

Author Conclusion:

Cross-sectional: Two child-feeding practices, the mothers’ concern about their child’s weight and pressure to eat were directly related to the child’s total fat mass. The results show that a mother’s concern for her child’s weight was related to a higher total fat mass in the child and that a mother’s pressure to eat was related to lower total fat mass in the child in boys and girls from both ethnic groups. Longitudinal:The two subscales of the Child Feeding Questionnaire explained 15% of the variance in total fat mass in both African American and white boys and girls (P<0.001) after correction for total lean mass and energy intake (which explained 5% of the variance in total fat mass).

Mothers’ child-feeding practices explained more variance in total fat mass after adjusting for total lean mass and energy intake than did dietary fat intake. The results support earlier research, which indicated that highly controlling feeding strategies may be related to interfering with children’s ability to self-regulate their energy intake.

Summary

Dietary fat intake did not explain any of the variance in total fat mass; energy intake from sources other than fat explained 5%, and child feeding practices explained 15% of the variance in total fat mass above and beyond energy intake.

Funding Source:
Government: USDA, NIH, GCRC
University/Hospital: University of Southern California, Research Triangle Institute, Pennsylvania State University, Baylor College of Medicine
Reviewer Comments:

Weaknesses:

  • Failed to assess physical activity and fitness measures which are part of energy expenditure.
  • Underestimation of energy intake with increasing adiposity.
  • Cross-sectional nature of study does not allow for conclusions concerning cause and effect.
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) 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? 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? 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? No
  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%.) No
  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.) Yes
  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? Yes
  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? No
  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? Yes
  6.6. Were extra or unplanned treatments described? No
  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? 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? No
  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? 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)? No
  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