PWM: Prescribed Diet Plan and Nutrition Education (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To observe the lipid profiles of obese African- American subjects verses obese Caucasian subjects before and after participation in a program of diet and exercise resulting in significant weight loss.
Inclusion Criteria:
  • >120% ideal body weight
  • Subjects who returned for the 10-week follow-up blood testing are included in this data analysis.
Exclusion Criteria:
  • If subjects weight was <120% of ideal body weight
  • If there was evidence of cardiovascular disease, diabetes, or other chronic systemic diseases.
Description of Study Protocol:

Treatment Program: All subjects participating in program began with an intensive 10-week period that focused on acute weight loss. Subjects attended a weekly 2-hour weight reduction clinic. They received diet instruction, nutrition education, exercise intervention/instruction, and behavior modification sessions.

Patients were started on a protein-sparing modified fast (PSMF) diet, supplemented with calcium carbonate, potassium chloride & daily multiple vitamin/mineral. In addition, patients were given a home-based exercise program including instructional video.

Weight % that matched subject’s height % was determined according to the National Center for Health Statistics (NCHS) %. Subject’s actual weight was then expressed as a percentage of IBW based on an equivalent weight and height %.

Subjects were classified as mildly obese (120-149% IBW), moderately obese (150-199% IBW), or severely obese (>200% IBW).

Statistical Analysis

Student paired t-tests; 2 x 2 multifactorial repeated measures ANOVA to compare female & male subjects.

Data Collection Summary:

Dependent

  • Change in Weight from baseline – 10 weeks (measured weight),
  • Change in BMI from baseline – 10 weeks (based on measured ht & wt – following standardized procedure),
  • Change in % IBW from baseline to 10 weeks,
  • Triceps & Subscapular skinfold thickness – average of 3 measurements,
  • Relative body fat (% of body weight and lean body mass in kg determined with formula by Slaughter and colleagues),
  • Fasting total cholesterol, Lipoproteins & Triglycerides (measured at baseline & at 10 weeks).

Independent

  • 10 week weight loss program.

Control Variables

  • Gender,
  • Ethnicity
Description of Actual Data Sample:

Original Sample: 53 children were initially evaluated for enrollment.

Withdrawals/Drop-Outs: 3 subjects excluded because of inappropriate entry age < 7 (n=2) & failure to report to the first class (n=1).

Final Sample: 50 subjects – 94% of initial enrollment (21 males, 29 females; 16 African-American, 34 Caucasians; aged 12.27 ± 2.67 years) were enrolled into 1-year weight reduction program.

Location: New Orleans, LA

Race/Ethnicity: African-American & Caucasian Population

SES: n/a

Summary of Results:

Anthropometric Measurements at Baseline & at 10 Weeks

Weight:

Significant weight loss was noted in all 50 subjects

Group Baseline kg 10 Weeks kg Significance
Combined 88.8±26.6 78.6±26.4 p<0.0001
African Americans 89.3±30.7 75.9±30.5 p<0.016
Caucasians 89.0±25.3 80.7±25.3 p<.029

%IBW:

Group Baseline % 10 Weeks % Significance
Combined 182.7±31.7 157.4±28.3 p<0.0001
African Americans 196.2±27.6 162.9±24.4 p<0.0001
Caucasians 181.2±33.7 155.3±29.9 p<.029

% IBW significantly decreased in all subjects (p<0.0001).

BMI:

Group Baseline 10 Weeks Significance
Combined 35.4±7.0 30.9±6.5 p<0.0001
African Americans 35.9±7.2 30.2±6.6 p<0.0001
Caucasians 35.3±7.0 31.4±6.7 p<.0025

BMI significant decreased in all subjects (p<0.0001).

Total Cholesterol:

Caucasian males reduced total cholesterol significantly at 10 weeks follow-up verses African-American males with no significant decrease in total cholesterol at 10-week follow-up.

The results for enrolled girls yielded no significant differences between African-American and Caucasian groups at baseline or at 10 weeks for total cholesterol and triglyceride levels.

Triglycerides:

TG levels significantly decreased across both ethnic groups & genders.

LDL:

LDL significantly decreased in Caucasian subjects but not African-American subjects.

Author Conclusion:

A multidisciplinary weight reduction program including diet, behavior modification, and exercise is an effective instrument for lower total cholesterol, LDL, & triglyceride levels in obese children. African-American children, however, display a less favorable change in lipid profile than Caucasian children.

Funding Source:
University/Hospital: Louisiana State University Medical Center, Children's Hospital of New Orleans
Reviewer Comments:

Strengths

All subjects reported full compliance with the home-based exercise program for the minimum required duration and frequency. The significant weight loss indicated that subjects were in compliance with the program diet.

Limitations

The article reported

“The details of the intervention have been described elsewhere”. Thus, the details of the intervention were not reported in this article.

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? N/A
  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? N/A
3. Were study groups comparable? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  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? N/A
  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? No
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  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? 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? Yes
  7.7. Were the measurements conducted consistently across groups? N/A
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)? N/A
  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? 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