Pediatric Weight Management

PWM: Family Influences (2006)

Citation:

Birch LL, Fisher JO. Mothers’ child-feeding practices influence daughters’ eating and weight. Am J Clin Nutr. 2000; 71: 1054-1061.

PubMed ID: 10799366
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To evaluate the influence of maternal child-feeding practices on daughters' eating and overweight.

Inclusion Criteria:

Five-year-old white, non-Hispanic girls and their mothers. The girls were living with both biological parents and within a five-county radius of the Pennsylvania State University.

Exclusion Criteria:
  • Girls with severe food allergies or chronic medical problems that affect food intake
  • Girls consuming vegetarian diets during the data collection.
Description of Study Protocol:

The study design tested a theoretical model of influences of the family environment on daughters' relative weight. Risk factors for overweight were measured as they influenced daughters' eating and weight outcomes. The relationship of mothers' relative weight to daughters' relative weight was determined as well, reflecting genetic and shared environmental effects on mothers' and daughters' relative weights.

Data Collection Summary:

Dependent

  • Daughters’ weight-for-height Z-score (measured)
  • Daughters’ food intake (mothers and daughters reported three 24-hour recalls).

Independent

  • Mothers’ relative weight (measured BMI), mothers’ restrained eating (the Eating Inventory, specifically the Restraint Subscale)
  • Mothers’ perceptions of daughters’ risk of overweight [Perceived Child Weight Subscale and the Concerns about Child Overweight Subscale from the Child-Feeding Questionnaire (self-report)]
  • Mothers’ restriction of daughters’ eating (CFQ Restriction Subscale, CQF Monitoring Subscale and Restricted-Access Questionnaire)
  • Daughters’ short-term regulation of intake (COMPX and the free-access procedure)
  • Restrictive child-feeding practices (mothers’ perceptions of daughters’ risk of overweight and mothers’ own restrained eating).

Statistical Analysis

Structural equation modeling to test models that describe maternal influences on daughters’ eating and relative weight.

Description of Actual Data Sample:
  • Initial N: 197 families (mother-and-daughter pairs)
  • Attrition: 156 pairs. 41 pairs were excluded due to reported behavioral problems by the girl during data collection, the girl was not comfortable or did not understand instructions, the girl ate a combined total of less than 1,257 kJ during the test meals or the girl consumed less than the required 80% of the pre-load meal.
  • Age: Daughters, 5.4±0.02 years; mothers, 35.4±0.3 years
  • Ethnicity: White, non-Hispanic
  • SES: Reported family income was less than $35,000 for 29%; $35,000 to $50,000 for 35%; and more than $50,000 for 36%. The parents were well-educated; the mean number of years of education was 15±2 years (range, 12 to 20 years) for mothers and 15±3 years (range, 12 to 20 years) for fathers.
  • Location: Pennsylvania.
Summary of Results:
  • Mothers' weights were modestly related to daughters' relative weights
  • Mothers’ restrictive control in feeding was a determinant of daughters’ relative weight
  • Greater maternal restriction predicted less adequate short-term regulation of energy intake by daughters (B=0.26). Beta was interpreted as a regression analysis weight. In other words, the more restrictive mothers were in terms of their daughters' intake, the more likely the daughters were to eat more during the snack periods.
  • This measure of short-term regulation of energy regulation was positively associated with daughter’s 24-hour energy intakes (B=0.19) and daughters’ 24-hour energy intakes were directly related to daughters’ relative weight (B=0.24).
  • The full-family environment model provided a substantially better fit than the simple path model that evaluated only mothers’ BMI as a predictor of daughters’ relative weight
  • Daughters’ weight status influenced mothers’ perception of daughters’ risk of overweight, which in turn influenced mothers’ child-feeding practices
  • The model provided an excellent fit for the data; however, a great deal of variance remained unexplained.
Author Conclusion:

Parenting influences are NOT all alike; parenting practices are shaped by the child’s characteristics of age, gender, birth order, physical appearance and specific abilities (non-shared family environment). 

The models illustrate a second path that depicts an environmental influence, maternal control in feeding and on daughters’ eating and relative weight: "...a mother's efforts to control her own weight, as measured by dietary restraint, in combination with her perceptions of her daughter's risk of overweight, predicted the mother's use of greater restrictive control in child feeding." Ironically, the mother's restrictive control was associated with greater energy intake.

These findings strengthen previous findings indicating that child-feeding practices are influenced by the weight status of the child.

Excessive control in feeding diminishes children’s capacity for self-regulation.

Funding Source:
Government: National Institutes of Health grant RO1 HD32973
Industry:
National Dairy Council
Commodity Group:
University/Hospital: Penn State University
Reviewer Comments:

This sample is not generalizable (white population, children living with both biological parents).

Limitations to the present study include:

  • Pathways of influence may differ among racial and ethnic groups and these were not studied
  • Mothers were the sole source of information and may have been biased
  • Non-shared family environment factors not studied include interactions with siblings, the influence of television and other media and the effects of physical activity.
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? No
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%.) Yes
  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? 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? 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? 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? 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? Yes
  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? No
  8.2. Were correct statistical tests used and assumptions of test not violated? ???
  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? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes