Pediatric Weight Management

PWM: Individual Child Counseling (2006)


Coates TJ, Killen JD, Slinkard LA. Parent participation in a treatment program for overweight adolescents. Int J Eat Disord 1982; 1: 37-48.

Study Design:
Randomized Controlled Trial
C - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
To explore methods for helping parents establish supportive environments for adolescent weight loss efforts and to assess directly the effects of parent training on adolescent weight loss.
Inclusion Criteria:
Subjects were required to be from 13 – 17 years of age, at least 10% above average weight for height (US Dept of Health, Education & Welfare. Height & Weight of Youths 12-17 yrs, 1973), and willing to come to Stanford 5 times per week for 15 weeks.
Exclusion Criteria:
Not specified.
Description of Study Protocol:

(Monetary deposits) Participants or their parents were required to pay a $35 non-refundable fee, deposit $130 for student participation & deposit $95 for parent participation. Deposits were returned to adolescents during the first 15 weeks of treatment for weight loss. Adolescents visited the treatment center each weekday morning and afternoon to be weighed. They received $1 of their deposit back if their weight was 1 pound below their weight recorded 7 days previously and also below their previous lowest weight in the program. The remainder of the deposit was refunded at the end of treatment and at follow up for blood test & questionnaire completion. Parent $ was refunded at the rate of $5/wk for 13 weeks for completion of homework assignments. The remainder was returned for questionnaire completion at the end of treatment and at follow up.

Adolescents were assigned to either a parent participation or a no-parent group. All adolescents attended weekly classes to learn self-management and weight loss skills. Participating parents attended separate classes focusing on the development of support skills to aid adolescents’ weight loss efforts.

15-week intervention over 20 weeks.

Weight loss & support skills were taught using a combination of videotape demonstrations, modeling, role playing, homework assignments & group discussions. The program emphasized calorie restriction but included sessions on the value of exercise. Students were encouraged to choose foods higher in complex carbohydrates and polyunsaturated fats and lower in cholesterol, sugar and saturated fats.

Statistical Analysis

Repeated measures analysis of variance.

Data Collection Summary:


  • % Above ideal body weight (measured during treatment & at 9 month follow up);
  • Reaction to the program and measures of satisfaction (reported posttest);
  • Plasma total cholesterol, Triglycerides & High Density Lipoproteins (HDL) (measured by fasting blood samples pretreatment, post-treatment & at follow-up);
  • Estimated intake of calories, saturated fat, polyunsaturated fat & cholesterol (Dietary questionnaire);
  • Regular physical activity over 1 week period (physical activity questionnaire);
  • Family & personal history of disease and overweight, previous weight loss attempts, personal efficacy regarding weight loss & other health-related habits (Demographic & weight history questionnaire).


  • Parent participation or no-parent group.

Control Variables

  • none noted
Description of Actual Data Sample:

Original Sample: not specified

Withdrawals/Drop-Outs: not specified

Final Sample: 31 subjects (11 males & 20 females).

Location: Stanford University – Stanford, CA

Race/Ethnicity: not specified

SES: Participants were largely from middle & upper-middle class families.

Age: mean age was 15.6 y.

Summary of Results:

% Above ideal weight

This variable was used as dependent variable because adolescents were changing in age & stature throughout the 18 months of the study (accounting for normal, developmental growth).

Students in no-parent condition reduced mean overweight by 5.1% from pretreatment to posttreatment, and showed a further decrease to 8.2% at follow-up.

Students in the parent participation condition reduced mean overweight by 8.4% from pretreatment to post-treatment and maintained that level at follow-up. Thus, both conditions ultimately reached the same level of % overweight but did so at different rates of loss.

Estimates of Dietary Intake

Changes at post & follow-up in recommended directions were observed from pretreatment to post-treatment for 4 of 5 variables (calories consumed in one week, mean daily intake of cholesterol, mean daily intake of saturated fat, mean daily intake of polyunsaturated fat – but not P/S Ratio).

Blood Lipids

Reductions in total serum cholesterol & LDL were observed but these changes failed to reach statistical significance.

Correlations Among Lipid, Dietary, Activity and Weight Variables

% above ideal weight was positively correlated with reported caloric intake & intake of cholesterol, saturated fat & polyunsaturated fat. There was a negative association between HDL, % above ideal weight, and total calories. Change in HDL was inversely related to change in relative weight & positively related to change in P/S ratio. Change in % above ideal weight was negatively related to change in P/S ratio and change in physical activity.

Participant Reactions

A majority of parents (72%) reported that they would enroll in a future program and 81% indicated that they would recommend the program to friends. Most adolescents (90%) reported that daily weigh-ins were helpful.

Author Conclusion:

Parent participation enhanced short term weight changes in adolescents but both groups showed equivalent changes at follow-up. These results show that modeling could be important during treatment, but that self-regulation (perhaps combined with reinforcement) plays a more important role in maintenance. The author’s impression in this study is that contingency systems and parental modeling and reinforcement enabled adolescents to achieve significant weight losses. Once weight loss skills were learned, even infrequent reinforcement from family & friends may have been sufficient to maintain losses. It is also possible that parents did not learn or apply the necessary behavior change skills. (Many parents reported difficulty relinquishing control over adolescents’ eating habits.)

Funding Source:
Government: NIH
Reviewer Comments:


  • 9 month follow-up after intervention’s end.


  • Small sample.
  • How subjects were assigned to parent participation or no-parent group was not specified.
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? 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) 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? No
  4.1. Were follow-up methods described and the same for all groups? No
  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? ???
  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? No
  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? ???
  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)? No
  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