Pediatric Weight Management

PWM: Prescribed Diet Plan and Nutrition Education (2006)

Citation:

Schwingshandl J, Sudi K, et al. Effect of an individualized training programme during weight reduction on body composition: a randomized trial. Arch Dis Child 1999; 81:426-8.

PubMed ID: 10519718
 
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:
  1. To evaluate a standardized training program for maintenance of fat free mass during weight reduction.
  2. To study the effect of changes in fat free mass during weight reduction on the long-term outcome.
Inclusion Criteria:

Obese children.

Exclusion Criteria:

None specified.

Description of Study Protocol:

Thirty children consented to participate and were randomly assigned to two groups:

  • Group A received standard dietary advice for weight reduction by a dietician at baseline, 4, 8, and 12 weeks of study and participated in training program twice weekly;
  • Group B had dietary intervention only.

 

Both groups participated in same 12-week dietary education program. General advice given by group teaching, including topics such as energy requirements, relation of different nutrients in a balanced diet (20% of total energy from protein, 30% from fat, 50% from carbohydrates), importance of fiber, vitamins, minerals, fluids.

Energy intake restricted to 4180 kJ/day in both groups; those older than 14 years restricted to 5016 kJ/day for girls and 5852 kJ/day for boys.

All participants received written information regarding restricted, balanced diet, and detailed information on daily allowance of each food component to avoid overconsumption.

At each visit (baseline, after 4, 8, 12 weeks, after 6 and 12 months), each participant received dietary re-education individually.

Individual 12-week training program developed according to recommendations of committee on sports medicine.

Training sessions took place twice weekly in public gym, approximately 60-70 mins for each session.

Warm up period and light stretch followed by two sets of exercises, all (except for dumbbell bicep curls) done on weightstacking machines in which resistance could be increased gradually.

Number of sets performed during training sessions increased after 2 weeks, up to as many as 3-4 sets for each exercise. Intensity expressed as 10 repetition maximum (max load child could perform 10 repeats with) and adapted during time course of strength gain.

Sets were pyramided – starting with light set (50% of 10 repetition maximum) and each following set using slightly higher load. If child able to perform more than 10 repetitions in final set, resistance increased for next training session.

Statistical Analysis

Paired comparisons t-test, Wilcoxon rank sum test, Spearman’s correlation coefficient.

Data Collection Summary:

Dependent

  • Weight; mean standard deviation score for body mass index (BMI-SDS);
  • fat free mass (FFM), estimated from resistance index (RI) obtained by bioelectric impedance analysis, height, and age using Shaefer equations (1994).
  • To assess repeatability of measurements, bioelectric impedance analysis performed on 36 non-obese children with type I diabetes; mean differences between measurements were 8.47 ohms for resistance and 0.28 kg for FFM.

Independent

  • Dietary intervention plus individualized training program or
  • dietary intervention alone.

Control Variables

None specified.

Description of Actual Data Sample:

Original Sample: Thirty obese children and adolescents (13 boys, 17 girls).

Withdrawals/Drop-Outs: none specified.

Final Sample: 30 obese children and adolescents analyzed at 12 weeks, 20 children reassessed at 1 year (67%).

Group A: 6 boys, 8 girls, mean age 11.0 (2.5) years, mean BMI-SDS 5.58 (2.46).

Group B: 7 boys, 9 girls, mean age 12.2 (2.7) years, mean BMI-SDS 5.33 (1.79).

Location: Graz, Austria

Race/Ethnicity: Not specified.

SES: Not specified.

Summary of Results:

In group A (diet + treatment), changes in BMI-SDS and FFM significant (weight change not significant).

  • Weight change: mean -0.68, SEM 0.71, p=0.35.
  • Change in BMI-SDS: mean -0.53, SEM 0.11, p=0.0003.
  • Change in fat free mass (FFM): mean 2.68, SEM 1.00, p=0.02.

In group B (diet only), only BMI-SDS changed significantly (changes in weight and FFM not significant).

  • Weight change: mean -0.49, SEM 0.67, p=0.47
  • Change in BMI-SDS: mean -0.51, SEM 0.18, p=0.01. 
  • Change in fat free mass (FFM): mean 0.43, SEM 0.41, p=0.31.

 

Mean change in FFM significantly different between groups A and B (group A, 2.68 (3.74) kg; group B, 0.43 (1.65) kg).

Change in FFM after 12 weeks weakly and inversely correlated with changes in body weight after 1 year for 20 subjects (r=-0.44, p=0.05).

Author Conclusion:

Standardized resistance training program adapted for obese children and adolescents significantly increased percentage FFM during weight reduction when compared with energy reduction only.

Increase in FFM during weight reduction was weakly associated with better long term outcome with respect to body weight.

Study aimed to prevent reduction in resting energy expenditure after weight loss by training program focused on increasing FFM; this training succeeded in increasing FFM during weight reduction.

Standardized training program can prevent reduction in FFM during weight loss in obese children.

Reduction in FFM during weight reduction might be risk factor for regain of weight.

Funding Source:
Reviewer Comments:

Weaknesses:

  • no inclusion/exclusion criteria specified
  • limited demographic information
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? No
  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? No
  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? 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%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  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? No
  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? 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? 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)? ???
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? ???
  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