Pediatric Weight Management

PWM: Prescribed Diet Plan and Nutrition Education (2006)

Citation:

Epstein LH, Wing RR, Penner BC, Kress MJ. Effect of diet and controlled exercise on weight loss in obese children.  J Pediatr 1985;107:358-61.

PubMed ID: 4032130
 
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:
To re-evaluate the role of exercise plus diet in weight control by having children participate in a structured exercise program during the first 6 weeks of exercise, which may facilitate the development of appropriate exercise behavior.
Inclusion Criteria:
  1. >=20% above ideal body weight (IBW) for height (defined according to WHO standards)
  2. no medical problems to contraindicate weight loss, exercise, or fitness testing
  3. at least one parent willing to participate
Exclusion Criteria:
None described
Description of Study Protocol:

Recruitment

Media coverage and physician and school nurse referral.

Randomization

Children stratified (on basis of age, percent overweight, and physical work capacity) and randomly assigned (method of randomization not described) to Group 1 (diet + exercise) or Group 2 (diet only).

Treatment

8 week intensive sessions + 10 monthly maintenance sessions with child and parent(s) treated separately

  • Diet – lecture, discussion, and written materials on Traffic Light Diet ( energy intake to 900-1200 kcals, nutrient density by eating no more than 4 ‘red foods’ per week which translates into decreasing intake of fat and simple carbohydrate-rich foods)
  • Exercise – children met an additional 3 times per week during initial 6 weeks (parents encouraged to do same exercise on own) + parents participated together with children in exercise at end of monthly maintenance sessions; consisted of aerobic activity (10 min warm-up + 3 mile walk/run)
  • Behavioral procedures
    • Self-monitoring (diet, weight, exercise, pulse rate)
    • Praise and modeling
    • Therapist contact (once/week for 8 weeks in person, once/month thereafter via phone)
    • Contracting (family deposited $80 before treatment, $20 of which was returned for each of the following:  attending ¾ weekly treatment meetings, child’s attendance at 2 all-day assessments (baseline & 2 months?), parent & child’s attendance at 6 month assessment, and parent and child’s attendance at 12 month assessment).

Statistical Analysis

  • 1-way ANOVA – to assess baseline differences
  • ANOCOVA – to assess changes over time
  • Dunn-Bonferroni multiple comparisons – for follow-up test
Data Collection Summary:

Dependent Variables

  • Weight
  • % Overweight
  • Fitness (submaximal physical work capacity testing via bicycle ergometry)
  • Physical activity (Leisure Time Activity survey modivi8ed for children)

 

Independent Variables

  • Diet + exercise (Group 1)
  • Diet alone (Group 2; control)

Control Variables

None

Description of Actual Data Sample:

Original Sample: 22 families, 23 children (1 family with 2 study children), 8-12 y, girls only

 

Withdrawals/Drop-Outs:  1 child after 8 wk treatment (95.7% completion) + 2 children by 6 mo assessment (87.0% completion) + 1 child by 12 mo assessment (82.6% completion).

No difference in drop out rate by group.

Final Sample: 18 families, 19 children (10 in Group 1, 9 in Group 2).

Location:  Pittsburgh, PA?

Duration:  12 months

Race/Ethnicity:  Not specified

SES:  Not specified

Summary of Results:

At Baseline: No differences in dependent measures

After 12 mo. Treatment

Weight

Diet + exercise

Diet alone

0-2 mo

 (p<.01)     

 (p<.05)

0-6 mo   

 (p<.01)      

 (p<.01)

0-12 mo 

 (p<.01)            

NS

Gp 1 < Gp 2 @ 6 mo (p<.05)

 % <20% over IBW:  no differences by group at 12 mo (50% in Group 1 and 44% in Group 2)

% Overweight

Diet + exercise

Diet alone

0-2 mo

 (p<.01)

 (p<.01)

0-6 mo   

 (p<.01)

 (p<.01)

0-12 mo 

 (p<.01)

 (p<.01)

Gp 1 < Gp 2 @ 6 mo (p<.05)

Fitness

Diet + exercise

Diet alone

0-2 mo

 (p<.05)

NS

0-6 mo   

 (p<.05)            

NS

0-12 mo 

 (p<.01)

NS

Gp 1 > Gp 2 @ 12 mo (p<.01)

Physical activity

No differences except from 0-6 mo (means below; p<.01) for the medium activity level (which includes intervention walking), results which are consistent with adherence to exercise program.

Group 1 – 45.0 to 145.5 level

Group 2 – 47.4 to 58.0 level

More Detail

The following table provides more detail on the study findings.

Weight Loss Intervention

Description

(Blank: not applicable, did not use intervention

NR: not reported, intervention was used, but outcome not reported)

Intervention Group

(Diet plus exercise)

Control Group

(Diet only)

Dietary Outcome

(i.e., any evidence that children actually eat differently?)

NR

NR

Physical Activity Outcome

(i.e., any evidence that children are more active or less sedentary?)

Measure on Leisure Time Activity Survey ± SD (significance of difference from baseline)

Baseline: 45 ± 29.9

6 months: 145 ± 59.6 (p<.01)

Measure on Leisure Time Activity Survey ± SD (significance of difference from baseline)

Baseline: 47.4 ± 36.0

6 months: 58.0 ± 32.9 (ns)

Behavioral/Socio-emotional Outcomes

(e.g., changes in skills, self esteem, etc.?)

NR

NR

Fitness Outcomes

(measures of changes in physical fitness)

Kilipond-meters per kilogram ± SD: (significance of difference from baseline)

Baseline: 6.6 ± 1.0

2 months: 7.9 ± 0.9 (p<.05)

6 months: 7.9 ± 0.7 (p<.05)

12 months: 9.1 ± 1.5 (p<.01)#

Kilipond-meters per kilogram ± SD: (significance of difference from baseline)

Baseline: 6.5 ± 1.4

2 months: 7.4 ± 1.8

6 months: 7.9 ± 1.2

12 months: 9.1 ± 1.9

Weight Outcomes

(how much? How long? Statistically significant?)

 

* between group differences significant at p<.05

 

# between group differences significant at p<.01

Weight: Mean ± SD (significance of difference from baseline)

Baseline: 53.77 ± 19.6

2 months: 49.31 ± 17.5 (p<.01)

6 months: 46.95 ± 17.0 (p<.01)*

12 months: 49.91 ± 19.1 (p<.01)

% Overweight: Mean ± SD (significance of difference from baseline)

Baseline: 48.0 ± 23.2

2 months: 30.7 ± 21.5 (p<.01)

6 months: 20.5 ± 22.6 (p<.01)*

12 months: 22.6 ± 29.3 (p<.01)

Weight: Mean ± SD (significance of difference from baseline)

Baseline: 53.95 ± 17.5

2 months: 50.77 ± 17.6 (p<.05)

6 months: 50.14 ± 19.4 (p<.01)

12 months: 52.59 ± 19.0 (ns)

% Overweight: Mean ± SD (significance of difference from baseline)

Baseline: 48.1 ± 17.6

2 months: 36.2 ± 19.0 (p<.01)

6 months: 29.3 ± 22.3 (p<.01)

12 months: 29.4 ± 22.5 (p<.01)

Author Conclusion:

Our results show that obese children who are provided a diet plus exercise program are significantly lighter after 6 months of treatment than are children given a diet only.

In addition, reliable improvements in fitness were observed only in children provided diet plus exercise. 

The pattern of weight loss does favor diet plus exercise, because children in the diet plus exercise group lost incremental amounts of weight, and percent overweight decreased from baseline to 2 months and further decreased to 6 months, whereas children in the diet alone group showed significant decreased only from baseline to 2 months, with maintenance of these changes.

Funding Source:
University/Hospital: NICHD
Reviewer Comments:

Strengths

  • Thorough description of study protocol,
  • measure of exercise compliance,
  • subjects stratified into groups on basis of several potential confounders.

Limitations

  • No control for potential confounders,
  • unclear what factors compared at baseline,
  • no assessment of diet compliance,
  • sample not fully described (e.g., in terms age, ethnicity, SES),
  • reasons for withdrawals not specified,
  • no non-intervention comparison group,
  •  no blinding of measurements.
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? ???
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? ???
  1.3. Were the target population and setting specified? ???
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? ???
  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? 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? ???
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? ???
  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? ???
  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? No
  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? No
  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? No
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