Pediatric Weight Management

PWM: Prescribed Diet Plan and Nutrition Education (2006)

Citation:

Epstein LH, Wing RR, Koeske R, Valoski A. Effects of diet plus exercise on weight change in parents and children. Journal of Consulting and Clinical Psychology 1984; 52:429-437.

PubMed ID: 6747061
 
Study Design:
Randomized controlled trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
  1. To report the comparison of diet with diet-plus-life-style exercise in a sample of overweight children and parents enrolled in a family-based obesity treatment program.
  2. To replicate previous findings on exercise and weight loss in adults and conduct the first controlled test of exercise on weight loss in children.
Inclusion Criteria:
  • Families with a child between ages of 8 and 12,
  • Child and participating parent between 20% and 80% over ideal weight for height,
  • Age and sex, parent and child with skinfold thickness measures greater than 85th percentile,
  • Child with no current psychiatric contact and no learning disability,
  • Parent willing to attend all treatment meetings,
  • No medical problem in parent or child that contraindicated exercise.
Exclusion Criteria:
  • Psychiatric contact,
  • Learning disability,
  • Medical problem that contraindicated exercise.
Description of Study Protocol:

Families were recruited by physician and self referral and in response to media advertisements. After screening, subjects randomly assigned to one of three groups:

  1. diet.
  2. diet plus exercise,
  3. waiting-list control.

Subjects in two treatment groups participated in 15 sessions, first 8 intensive sessions met weekly, remaining 7 spread out over 20 weeks with 3 biweekly meetings and 4 monthly meetings. Final visit was scheduled 12 months after program start.

Parents required to deposit $85 at program start, to be returned incrementally at 8 intensive treatment meetings, maintenance meetings, and 5 and 8 month meetings.

Point economies implemented by parents used to reinforce child diet and exercise changes; habit books promoted regular review of habit change by parent and child.

Each of 15 sessions involved group review of short module, group discussion, and individual review of parent and child habit books and changes by trained therapists.

Families seen in groups, with parents and children separated.

Topics of treatment meetings included nutrition, exercise, food buying, motivation, dealing with friends and relatives, self-control, relapse, exercising in heat, label reading.

Diet treatment involved calorie controlled Traffic Light Diet, where foods separated into red, yellow and green depending on calorie content per serving to decrease saturated fat and sugar intake and increase nutrient density per calorie.

Diet-plus-exercise subjects given life-style change exercise program that required increasing voluntary caloric expenditure above normal through series of gradual steps, from 1400 kcal in week 1 to 2800 kcal by week 12. Participants earned behavior points exchanged for incentives for exercising according to point list bsed on multiples of metabolic rates.

Children in diet group provided information on low expenditure stretching and calisthenics only and were not provided any suggestions or supports for systematic exercise.

Statistical Analysis:

Repeated measures ANOVA to evaluate initial effects of group assignment and time; correlation analysis to evaluate relationships between initial level and degrees of change, between 0 and 6 month change, 6 and 12 month change, and between parent and child change; discriminant analyses to predict program success.

Data Collection Summary:

Dependent Variables

  • Weight (measured on balance beam scale);
  • Height (obtained on specially constructed height measure);
  • BMI (weight(kg)/height(m)2);
  • Number of red foods eaten each week;
  • Weeks under red food limit;
  • Days/weeks under caloric limit;
  • Days/weeks with complete recording;
  • Number of exercise points;
  • Days/weeks over exercise goals;
  • Percentage overweight

Independent Variables

  • Exercise and diet,
  • Diet alone,
  • No treatment
Description of Actual Data Sample:

Original Sample: 53 families (18 in each treatment group, 17 in control group)

 

Withdrawals/Drop-Outs: 6 families (3 treatment, 3 control) at 6 months; 2 treatment families at 1 year.

Final Sample: At 6 months, 47 families (89%) (15, 18, 14 per group); at 1 year, 34 of 36 treatment families (94% of treatment sample) remeasured.

Location:  Not specified.

Race/Ethnicity: Not specified.

SES: Not specified.

Summary of Results:

For children at 6 months, two treatment groups significantly lighter than control group, who gained weight.

Treatment children lighter at 6 months and 1 year than baseline, but no differential effect of treatment.

 

Both adult treatment groups significantly lighter than control at 6 months.

Results for treated parents at 1 year did show significant differential effect of treatment, indicating superior effect of diet plus exercise at 6 months and stability of weight loss from 6 months to 1 year in diet-plus-exercise group relative to diet group, who regained weight.

Baseline BMI unrelated to 0-6 month change for parents or children.

Parent changed during 0-6 months highly related to those of their children.

Initial BMI level significantly related to 6-12 month change for parents but not children.

0-6 month change in BMI showed significant negative correlation with 6-12 month BMI for parents (parents who lost the most weight during first 6 months regained the most during the second 6 months).

Compliance measures showed that children adhered better to program than parents.

Discriminant analyses showed best predictor of final BMI was initial BMI for both parents and children.

Predictions of who would achieve and maintain nonobese status also yielded BMI as best predictor in parents and children.

Author Conclusion:

Addition of exercise to a diet improves the amount of relative weight change at 6 months and 1 year in adults.

However, exercise did not add to the general effects of dieting for children at the end of 6 months or 1 year. This may be due to poorer adherence to exercise among children relative to adults, increased importance of exercise for adults relative to children, or fact that children may have to do more exercise than adults so absolute calorie expenditure is similar.

Design seems appropriate for evaluation of combined effects of dieting and exercise.

Correlational analysis showed no relationships between initial weight and weight change at 6 months, but changes experienced by parents and children strongly related within families.

Strong negative relationship between weight change in first 6 months and weight change from 6-12 months in parents; no relationship between treatment and follow up weight change seen in children.

Initial relative weight served as best predictor of final relative weight or maintenance of nonobese relative weight. Exercise was not an important predictor of final relative weight, but it was important in determining maintenance.

Correlation between parent and child weight loss during treatment and the breakdown of this relationship over time suggests that mechanisms for long term change in children may differ from those of short term changes.

 

Parents and children lost significant amounts of weight over 1 year period.

Changes for parents and children are most correlated during 6 months of treatment, uncorrelated during 6 months of follow up.

Contribution of present exercise program to relative weight change is more important in adults than in children.

Funding Source:
University/Hospital: University of Pittsburg
Reviewer Comments:

Limitations:

  • no blinding

Strengths:

  • compliance measured
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? N/A
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? N/A
  1.3. Were the target population and setting specified? N/A
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? ???
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) No
  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.) 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? 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? ???
  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? 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? Yes
  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? 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? Yes
  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? 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? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  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)? N/A
  8.6. Was clinical significance as well as statistical significance reported? N/A
  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