Pediatric Weight Management

PWM: Physical Activity and Inactivity (2006)

Citation:

Epstein LH, Wing RR, Koeske R, Valoski A. A Comparison of Lifestyle Exercise, Aerobic Exercise, and Calisthenics on Weight Loss in Obese Children. Behavior Therapy 1985;16;345-56.

 
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:

The present study is designed to assess the reliability of the effects of diet plus lifestyle versus diet plus programmed aerobic exercise over an extended two year observation interval. An active control group that was provided low-expenditure calisthenics exercises was included in the comparison to permit examination of the nonspecific effects of exercise.

Inclusion Criteria:
  1. child between the ages of 8-12,
  2. child and at least one participating parent over 20% over ideal weight for height,
  3. parent and child showing no problems that would interfere with regular exercise.
Exclusion Criteria:

None cited.

Description of Study Protocol:

Subjects were selected and randomized into three groups:

  1. diet plus programmed aerobic exercise,
  2. diet plus lifestyle exercise,
  3. diet plus calisthenic exercise.

Families assigned to each of these programs were seen weekly for 8 sessions, monthly for an additional 10 sessions, and then were seen at 24 months for measurement.

Each child and parent were provided a 1200 calorie diet, based on our Traffic Light Diet.  During treatment, children and parents kept daily food records which were used to provide feedback on caloric intake and nutritional balance.  Once children had lost to within 10% of their ideal weight, they were placed on a maintenance program, in which caloric intakes were increased by 100 calorie increments as long as weight was maintained.

The aerobic exercise program was a walk, run, bicycle or swim program, based on the family’s preference.  The parents and children were to exercise three times a week.  Participants were instructed in heart rate monitoring and trained to exercise at 60%-75% of their age-adjusted maximal heart rate.

The lifestyle exercise program was designed to be isocaloric to the aerobic exercise program, although the subjects were allowed to choose exercises or activities from an exercise menu, and were not instructed to exercise at a particular intensity.

The calisthenics program involved having subjects perform 6 of 12 calisthenics 3 times per week.  The repetitions were increased in intervals similar to those used for the programmed exercise group.

Four behavioral procedures were used to influence behavior change:

  1. Self-monitoring: Self-monitoring involved having parents and children record their caloric intake and exercise behavior in small “habit books”.  At the end of each day, the total amounts of each were transferred to a summary sheet in the back of the habit book. 
  2. Modeling: Modeling involved teaching the parents and children the importance of each setting a good example for one another.
  3. Contingency contracting: Contingency contracting for the parents required the deposit of $85.00 which was returned to them for attendance as follows:  $15 for attending six of the seven treatment meetings, $5 for attending eight of the monthly meetings, and $15 for attending the 6-month and 12-month measurements.
  4. Parent management: Parent management involved instructing the parents in the use of modeling and reinforcement for child behavior change and maintenance of behavior.  Parents were taught to administer a structured incentive system to promote behavior change.  Children were reinforced for adherence to the diet and one of three exercise program.  At the first treatment meeting, parents checked reinforcers that would be acceptable to them from a reinforcement menu that included activities and privileges, but not food or material reinforcers.  The children then divided the potential reinforcers into three categories which were assigned three different point values.  Children earned points each week for adherence to the diet and exercise parts of the program.  After approximately 6 months (dependent on the child’s performance) on the system, the parents were encouraged to fade out the point system and utilize social reinforcement to regulate child eating and exercise behavior.

Compliance to the program was reinforced as follows: children earned seven points per week for meeting the exercise goal, and two bonus points per week for eating four or fewer red foods.  The point values were set up so that perfect adherence for 1, 2 or 3 weeks would earn enough points for the three levels of reinforces. 

Data Collection Summary:

Height was measured on a lab constructed height board. Weight was measured on a balance beam scale.  % overweight was established in reference to ideal weight for height, age, and sex.  BMI was calculated according to the following formula: kg/m2.

Physical work capacity was assessed at baseline, 2, 6, and 12 months for parents and children using a graded bicycle ergometry test in which the subject worked for 3 minutes at a workload, with the workloads increasing at 3-min intervals.

The workloads began at 150 kpm, and increased in 150 kpm increments for the children and mothers, and began at 300 kpm and increased in 300 kpm increments for the fathers.  The heart rate during the last min (steady state heart rate) at each workload was entered into a linear regression equation to predict the amount of work the subject could do at 150 beats per in (PWC150).

Eating behavior was measured at baseline, 6 and 12 months by use of a standardized inventory of eating behaviors.  During the initial 8 weeks of treatment, compliance to three aspects of the program, eating, exercise, and self-recording were assessed by review of the daily habit record books.

Description of Actual Data Sample:

35 families; 21 girls and 14 boys

Summary of Results:

Weight Outcomes

The child results showed significant (p < .05) differences between the three groups only at the 2-year follow-up. Significant decreases in percent overweight were observed for all three groups from 0 to 2, 6, and 12 months.  At month 24, the lifestyle group had maintained relative weight changes, while the other two groups had returned to baseline levels.  Absolute weight showed a similar pattern, with equal treatment effects shown for all groups up to 12 months.  Over the 24-month study, subjects in the lifestyle group had gained 10 pounds, while subjects in the other two groups had gained over twice that amount.

Parents also showed significant (p < .05) decreases from baseline to 2, 6, or 12 months.  However, significant differences were not shown for parent percent overweight or weight across groups at month 24, though a similar pattern, with equal treatment effects shown for all groups up to 12 months.  Over the 24-month study, subjects in the lifestyle group had gained 10 pounds, while subjects in the other two groups had gained over twice that amount.

Parents also showed significant (p < .05) decreases from baseline to 2, 6, or 12 months.  However, significant differences were not shown for parent percent overweight or weight across groups at month 24, though a similar pattern for the children was observed, with better long-term changes for the parents in the lifestyle group.

Fitness Outcomes

Fitness data were available for 29 of the 35 children at baseline, 2, 6, and 12 months.  No significant improvements in fitness were observed for children after 2 months.  After 6 months, children in the lifestyle group showed significant (p < .05) improvement in fitness from pre (407.3 ± 186.7) to 6 months (515.0 ± 205.5), but they returned to baseline levels of fitness at 1 year (440.7 ± 131.3).  Children in the aerobic exercise group were the only subjects to show significant (p < .05) effects at 1 year (394.3 ± 154.3 to 517.0 ± 153.9).  No changes in fitness were observed for children in the calisthenics group.  Parent fitness data, available for 18 parents at 6 months and 15 parents at 12 months, showed no improvements in fitness at any measurement.

Children showed significantly (p < .001) improved eating behavior from pre to 6 months and 1 year with no differences across groups.  The average EBI went from 69.4 at baseline to 88.4 at 6 months and 86.1 at 1 year.  Parents showed similar average improvements in eating behavior (p < .01) going from 68.8 at baseline to 93.8 at 6 months and 90.5 at 1 year.  No differences were observed across groups.

Compliance Outcomes

The compliance results showed no differences during treatment across children or parents on the number of days per week below 1,200 calories, the number of weeks meeting the exercise goal, and the number of weeks that recording was complete.  On the average across groups, children kept under 1,200 calories for 6 days of the week, met the exercise goal for 3.5 weeks, and recorded completely for 6.3 days per week.  Parents kept under the calorie limit for 5.6 days per week, met the exercise goal for 2.9 weeks, and recorded completely for 5.7 days per week.

Compliance and BMI change during the first 8 weeks of treatment were related for exercise (r = -.35, p < .05) and recording (r = -.69, p < .01), for children and for keeping below the calorie limit (r = -.46, p < .01), exercise (r = -.44, p < .01) and recording (r = -.54, p< .01) for parents.

Author Conclusion:

Lifestyle exercise shows a reliable superiority over programmed exercise in the maintenance of long-term weight losses in children. In addition, the comparability of short-term changes for all three exercise programs suggests that at least some of the efficacy of exercise in weight control results from nonspecific rather than specific factors.

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

Limitations:

  • No power analysis
  • small group size
  • Reasons for withdrawal not described nor how many subjects dropped out per group nor when this occurred, 6 mos., 1 year or 2 year
  • No intent to treat analysis
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? 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) Yes
  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? No
  4.1. Were follow-up methods described and the same for all groups? ???
  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? ???
  4.4. Were reasons for withdrawals similar across groups? No
  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? Yes
  6.6. Were extra or unplanned treatments described? Yes
  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? 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? 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)? 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? No
9. Are conclusions supported by results with biases and limitations taken into consideration? ???
  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