Pediatric Weight Management

PWM: Prescribed Diet Plan and Nutrition Education (2006)

Citation:

Epstein LH, Wing RR, Koeske R, and Valoski A. Effect of parent weight on weight loss in obese children.  Journal of Consulting and Clinical Psychology.  54(3):  400-401, 1986.

PubMed ID: 3722572
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
One goal of the present study was to investigate the role of parent weight in the treatment of childhood obesity. A second goal of this study was the evaluation of self-control on childhood weight control.
Inclusion Criteria:

Forty-one families with 8-12 year old children:

  • between 20% and 80% over their ideal weight,
  • having triceps skinfold values greater than the 85th percentile
  • with no psychiatric contact or learning disability were accepted into the study.

Twenty-four children had at least one obese parent (>20% overweight with triceps fatfolds greater than the 85th percentile, Garn & Clark, 1976), and 17 children had parents who were not currently obese.

Exclusion Criteria:

Those whom have had psychiatric contact or learning disability.

Description of Study Protocol:

Children were randomly assigned to one of two treatment conditions:

  1. parent control
  2. child self-control

Parent weight was crossed with treatment condition.

The two treatments involved 8 weekly treatment meetings with 10 monthly meetings in which parents and children were seen separately over a 1-year period.  Parents deposited $85 in a deposit contract to be returned for attendance at treatment and maintenance meetings.  Children and overweight parents were provided a 1200 kcal diet and life-style exercise program.  Nonobese parents were placed on a caloric level that would maintain their weight and were given the same exercise program as the obese participants.

A point economy, in which children earned points backed up by activity and privilege reinforcers, was used to regulate child eating and exercise habits.  In both groups, determination of when goals were met and awarding of points were made initially by therapists, with parents being trained to take over contingency control.  These skills were then faded to the children in the child self-control condition.  Parents remained in control of the back-up reinforcers for both conditions.

Weight and height were measured at 0, 2, 6, 12, and 36 months, with percentage overweight calculated for children and adults.  Eating behavior was measured at 0, 2, and 6 months using the Eating Behavior Inventory (EBI).  Fitness was measured at 0, 2, and 6 months by the Montoye Step Test.  Recovery heart rates used to determine fitness were converted to fitness percentiles set so that the lower the percentile, the better the fitness.  Compliance during the initial 2 months of treatment was determined weekly by review of daily habit records on the basis of whether participants stayed below the caloric limit, met the exercise goal, and kept complete records.  Twenty-five percent of the records were independently coded by a second observer with agreement exceeding 80% for all categories.

Data Collection Summary:

Statistical Analysis

For statistical analysis, relative weights were standardized within the two parent weight groups based on baseline values, equating both the mean and the variance between groups.

Means were compared using Dunn’s planned comparison tests based on three-factor mixed analyses of variance, with parent weight and treatment condition (parent/child control) as between factors, and time (pre, 6, 12, 36 months) as the within factor.

 

Description of Actual Data Sample:

Original Sample: Forty-one families with 8-12 year old children

 

Withdrawals/Drop-Outs:

Final Sample: Three-year data were available for 38 families, a follow-up rate of 93%.

Location:  not stated          

Race/Ethnicity:  not given

SES:  not given

Summary of Results:

Baseline Measures

One-way analysis of variance at baseline showed that obese and nonobese parents did not differ in age or height but that obese parents weighted more and had greater Body Mass Index (BMI; kg/m2) and percentage overweight scores (p < .01) than nonobese parents. Obese children of obese parents had greater BMI (p = .03) and percentage overweight scores (p = .04) and were marginally (p<.10) heavier than obese children of nonobese parents.  There were significant differences in the variances in the two populations, owing to greater variability in the response of children of obese parents to treatment.

Outcomes

For children, a significant time effect, F(3, 102) = 38.37 p < .001, and a significant Time X Parent Weight interaction, F(3, 102) = 3.45, p<.02, were observed.  No effects of treatment were shown between groups.  Significant (p<.01) decreases from baseline to 6 months for children of both nonobese z = -1.34, % = -17.2 and obese (z = -0.92, % = -14.3) parents were shown.  At 1 year, children of nonobese parents were significantly (p<.01) lighter than baseline (z = -1.28, % = -16.3) and lighter (p<.01) than children of obese parents (z = -0.49, % -7.7), who were now not different from baseline.  At 3 years neither group was significantly different from baseline (z = -0.47, -0.05, % = -5.6, -0.9, for children of nonobese and obese parents, respectively).

Three-factor mixed analysis of variance performed on the parents’ percentage overweight data showed no differential changes as a function of parent weight or parent/child control.  Obese parents remained heavier (main effect of parent weight) over the 3 years of treatment (p<.01).

Children with nonobese parents were more compliant than those with obese parents for calorie limit, F(1, 31) = 6.74, p = .01, exercise goal, F(1, 31) = 5.95, p = .02, and recording completely, F(1, 31) = 4.89, p =.03.  Obese children with nonobese parents had better eating behavior (EBI scores) across all measurements, F(1, 24) = 7.89, p<.01.  Significant changes over time, F(2, 48) = 45.77, p<.0001, were also observed.  Planned comparisons showed that the rate of improvement in eating behavior from 0 to 6 months was greater (p<.05) for children of nonobese (+21.6) than of obese (+14.5) parents.

No differences in eating behavior as a function of parent weight or treatment category were shown for the parents.  No differences in child fitness were shown as a function of parent weight category, although significant (p<.01) improvements in fitness were observed:  from 66th percentile at baseline to 32nd percentile at 2 months and 45th percentile at 6 months.

Author Conclusion:

“Parent weight influenced outcome only during the first year of treatment, mainly due to differences in relative weight for children from months 6 to 12.  At the end of 1 year of treatment, children of nonobese parents had 2.1 times the change in percentage overweight (-16.3% vs. -7.7%) as did children of obese parents.  Children with nonobese parents were more compliant to the eating, exercise, and self-monitoring components of treatment than were those with obese parents, and they also showed better improvements in eating behavior.  These differences may be responsible for the superior 1-year results found for children of nonobese parents.”

The results show that parent and child self-control produced similar outcomes.  These results are encouraging because they show that after training, children managed the program as well as their parents.  Perhaps variations of the program involving more training, introducing the self-observation components of self-control earlier, or placing the children in control of the administration of the reinforcers would improve the results of child self-control versus parent control.  Although the overall results showed significant relative weight decreases over 1 year, the clinical utility of these treatments is limited by their failure to produce long-term results.

Funding Source:
Government: NICHD
University/Hospital: University of Pittsburgh School of Medicine
Reviewer Comments:

The pattern of results observed between children with obese and nonobese parents showed differences in the pattern of weight regulation, with children of obese parents showing more rapid regain. Mechanisms that may account for these differences include genetic, physiological, or behavioral factors. 

Further research into the mechanisms that lead to differential maintenance of weight loss for children with nonobese or obese parents would be useful for tailoring weight control programs to particular family characteristics.

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? No
  2.4. Were the subjects/patients a representative sample of the relevant population? No
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) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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? ???
  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.) ???
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? ???
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? No
  4.4. Were reasons for withdrawals similar across groups? ???
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? ???
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? ???
  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.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? ???
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? ???
  5.5. In diagnostic study, were test results blinded to patient history and other test results? ???
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? ???
  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? ???
  6.6. Were extra or unplanned treatments described? ???
  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? ???
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? 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)? Yes
  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? ???
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