Pediatric Weight Management

PWM: Prescribed Diet Plan and Nutrition Education (2006)

Citation:

Sothern, M., Despinasse, B., Brown, R., Suskind, R., Udall, J. and Blecker, U. Lipid profiles of obese children and adolescents before and after significant weight loss: differences according to sex. Southern Medical Journal 2000; 93: 278-282.

PubMed ID: 10728514
 
Study Design:
Non-Randomized Controlled Trial
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To observe the lipid profiles of obese girls versus obese boys before and after participation in a program of diet and exercise resulting in significant weight loss.

Inclusion Criteria:

Subjects enrolled in 1 year weight reduction program at Children’s Hospital of New Orleans who returned for 10-20 week follow up blood testing.

Exclusion Criteria:
Weight less than 120% of IBW, evidence of cardiovascular disease, diabetes, or other chronic systemic disease.
Description of Study Protocol:

Comprehensive history taken and physical exam done before baseline measurement. Individual IBWs calculated by measuring weight and height; subjects classified as mildly obese (120-149% IBW), moderately obese (150-199% IBW) or severely obese (>=200% IBW).

All subjects began with intensive 10-20 week period that focused on rapid weight loss. Color coded handbooks used to explain all aspects of weight loss and serve as positive reinforcement. Subjects generally reached lower category of obesity during this phase. Weight maintenance program was prescribed once next lower level of obesity was achieved.

During this time subjects attended weekly 2 hour weight reduction clinic, where they received diet instruction, nutrition education, exercise intervention instruction, behavior modification sessions.

Patients started on protein-sparing modified fast diet with 2 g protein/kg IBW daily (up to 100g) that supplied ~3350 kj/day. Ketosis induced by limiting carbohydrate intake to 20-25 g/day. Two cups vegetables (except high starch) allowed daily. All participants received supplemental calcium carbonate (two 500 mg tablets twice a day providing 800 mg elemental Ca), supplemental potassium chloride (10-20 mEq twice daily), and daily multivitamin and mineral supplement. Subjects encouraged to drink at least 2 L water or sugar free beverage daily.

Dietary adherence monitored through self reported urine ketone records.

Subjects given home based exercise program including video; subjects and family members participated in 30-45 minutes moderate intensity exercise during weekly intervention meeting.

All subjects required to report exercise duration and frequency in exercise record booklets.

Statistical Analysis

Paired student t-test to analyze anthropometric and lipid profile data for all subjects; 2x2 multifactorial repeated measures ANOVA to compare male and female subjects.

Data Collection Summary:

Dependent

  • Weight (electronically calibrated scale, measured weekly);
  • height (stadiometer, measured weekly);
  • BMI (calculated at enrollment and 10 weeks);
  • triceps and subscapular skinfolds (Harpenden calipers, mean of three values used);
  • relative body fat as percentage of body weight and lean body mass (kg) (determined by formula of Slaughter et al);
  • %IBW (weight percentile matching subject’s height percentile determined according to NCHS percentiles, actual weight expressed as percentage of IBW based on equivalent weight and height percentile);
  • fasting total cholesterol, lipoprotein, triglyceride levels (measured at enrollment and at 10 weeks, 15 hour fast prior to testing, determinations made by certified clinical laboratory, comprehensive metabolic profile for each subject).

Independent

  • sex

Control Variables

 

Description of Actual Data Sample:

Original Sample: 53 children

Withdrawals/Drop-Outs: 2 excluded for inappropriate entry age (<7 years); 1 excluded for failure to report to first class

Final Sample: 50 patients (21 boys, 29 girls, age 12.27 +/- 2.67 years)

Location: New Orleans, LA

Race/Ethnicity: not specified

SES: not specified

Summary of Results:

All obese subjects reported full compliance with minimal home based exercise program for duration and frequency.

Overall attendance rate of 88.9% ± 11.4% by treatment subjects.

Weight:

Significant weight loss was noted in all subjects

Group Baseline kg 10 Weeks kg Significance
Combined 88.75±26.64 78.58±26.4 p<0.0001
Girls 88.45±27.94 79.0±27.72 p<0.05
Boys 89.17±25.4 78.0±25.13 p<0.0004

%IBW:

Group Baseline % 10 Weeks % Significance
Combined 182.73±31.67 157.37±28.27 p<0.0001
Girls 179.67±36.79 156.8±32.32 p<0.0001
Boys 186.95±23.02 158.15±22.24 p<0.0001

% IBW significantly decreased in all subjects.

BMI:

Group Baseline 10 Weeks Significance
Combined 35.38±6.98 30.89±6.49 p<0.0001
Girls 35.47±7.86 37.71±7.47 p<0.017
Boys 35.26±5.73 29.75±4.77 p<0.0001

BMI significant decreased in boys and in the overall group. However, according to Table 2 in the article, BMI for girls increased during the 10 week period. The reported BMI changes for the girls in Table 2 seems unlikely since--over the 10 week period--weight decreased for girls (an average of about 10 kg), while height increased for girls (by an average of about a centimeter). No other values are reported in the text.

Other Findings

  • No significant differences observed between male and female obese treatment groups in weight, height, percentage IBW, and BMI during two testing periods (baseline and 10 weeks).
  • Significant effect over time for both females and males in total cholesterol and triglyceride levels (no significant differences between males and females).
  • LDL levels decreased significantly in female subjects (p<.026), whereas no significant change in overweight males (p=.069). HDL levels did not change significantly in either group.
  • Male and female LDL values were clinically different at baseline, but not statistically different at baseline.
  • Despite significant weight loss observed, no significant changes in lean body mass in females or males at baseline and at 10 weeks.
  • Overall, significant improvements observed for changes in percentage IBW and total cholesterol and triglyceride levels.
Author Conclusion:

Girls had significantly different total cholesterol and triglyceride values from those of boys at entry into the program.

Girls had decreased LDL levels; both groups maintained HDL values seen at baseline.

Boys had significantly different total cholesterol and triglyceride values at entry into the program.

Multidisciplinary weight reduction program including diet, behavior modification, and exercise can successfully treat mild, moderate and severe degrees of childhood obesity, leading to improvement in body composition, percentage of IBW and BMI. Furthermore, this type of intervention is effective in lowering total cholesterol and triglyceride levels in obese children. In addition, girls tend to be more susceptible than boys to a decrease in LDL levels, which might result in increased cardiovascular protective effect.

Funding Source:
University/Hospital: Louisiana State University School of Medicine, Alfred I. duPont Hospital for Children,
Reviewer Comments:

Weaknesses:

  • no control group,
  • no demographic information
  • likely typo in Table 2 regarding changes in girls' BMI.
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? No
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? No
  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.) No
  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? 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? N/A
  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.) N/A
  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? ???
  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? 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? ???
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? N/A
  9.2. Are biases and study limitations identified and discussed? N/A
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? N/A
  10.2. Was the study free from apparent conflict of interest? N/A