PWM: Prescribed Diet Plan and Nutrition Education (2006)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
The aim of the GO GIRLS! Project was to develop and test the feasibility and potential effectiveness of an obesity intervention for low-income, African American adolescent women.
Inclusion Criteria:
  • female
  • living in or near the public housing development
  • age 11-17
  • overweight based on either BMI>85th % for age and sex or percentage body fat greater than 35% based on DEXA. In event that neither measurement was available, staff determined eligibility based on visual inspection.
Exclusion Criteria:
Not specified
Description of Study Protocol:

Recruitment

  • Presented as a "nutrition and physical activity program for overweight girls".
  • At each public housing development, at least one presentation was made at a residents association meeting, during which names, phone numbers and addresses of potential particpants were obtained.
  • Posters and flyers were placed around each development, and when possible, distributed door to door.
  • In each development, a community liason was hired to identify and recruit potential participants.
  • Names obtained from other health and social programs being conducted in each development.
  • Guidance counselors at local schools were asked to refer possible participants.

Study Design

  • Nonrandomized trial

Intervention

  • The program was conducted in 4 to 6-month intervention cycles over 2 years.
    • Four inner city sites
    • For the first four months, sessions were conducted twice per week usually after school.
    • For the last two months, sessions were conduted weekly.
    • The intervention was designed to:
      • Increase positive health and social outcome expectations for losing weight
      • Increase negative outcome expectations for remaining overweight
      • Increase participants' confidence in their ability to modify diet
      • Increase physical activity patterns.
  • Target behaviors of the intervention included:
    • Increased fruit and vegetable intake
    • Decreased fat intake
    • Decreased fast food intake
    • Decreased television viewing
    • Increased physical activity
    • Also learned communication skills to ask parents to shop and prepare healthier foods.
  • Each session comprised included the following:
    • Interactive educational/behavioral activity
    • Thirty to sixy minutes of physical activity
      • Objective of physical activity program was to expose participants to a wide range of options
    • Preparation and tasting of low-fat, portion-controlled meals
    • Homework assignmentonce per week linked to day's nutrition or exercise activity
  • Incentives were used to encourage participation in the assessment protocol, attendance and participation at sessions.

Statistical analysis

  • No control group so results from high attenders (>50% of the sessions) was compared to low attenders.
  • Six month outcomes were compared by analysis of variance adjusting for baseline values and age.

 

Data Collection Summary:

Timing of Measurements

  • Baseline
  • Six months (post-intervention).

Dependent variables

  • Dietary measures
    • Diet
      • Modified National Cancer Institute Health Habits and History FFQ
      • Three 24 hour recalls (three sites only) via telephone. Administered in home for girls without telephones.
    • Eating style (six item index): validated?
    • Low-fat eating practices (eighteen item index)
    • Perceived change index
    • Preference for seven high-fat/high-sugar and 32 low-fat/high-fiber items
    • Neophobia (seven item scale): trying new foods
    • Emotional eating index: not validated
  • Physiologic measures
    • Adiposity
      • BMI (used NHANES I reference data for cut-offs)
      • Two-site skinfold (tricepts and subscapular): converted to percentage body fat
      • DEXA
    • Nonfasting total and HDL cholesterol
    • Blood pressure
    • Aerobic capacity – VO2 (treadmill test)
  • Psychosocial measures:
    • Outcome expectations for eating healthier and losing weight (nine-item scale)
    • Self-esteem (ten item scale)
    • Preoccupation with weight & food (twenty item scale): validated?
    • Social Support from family and friends to eat healthier & exercise (twelve item scale);
    • Self-efficacy related to losing weight & modifying dietary, exercise, and cooking patterns (twenty-five item scale)
    • Health knowledge related to nutrient content of foods, understand food labels and health effects of fat and fiber (fifteen item index)
    • Perceived weight: very underweight (1) to very overweight (5)
  • Physical activity
    • Physical activity (one week recall)
    • Physical activity preference
    • Sedentary behaviors index.

 

Independent variable

  • Response to nutrition and physical activity intervention between low and high attenders.

Control Variables

  • Baseline values
  • Age.

 

Description of Actual Data Sample:

Initial N: N=57 females

  • Low Attenders: N=31
  • High Attenders: N=26

Attrition (final N): N=56

  • Posttest data (at least one physiologic or dietary variable) were collected.
  • Sample size at posttest ranged from 38-47 depending on the outcome.
    • Some instruments not used at the first site
    • Some participants completed only parts of the assessment.

Age: mean: 13.5 years (range 11-17)

Ethnicity: African American

SES: low-income community

Anthropometrics (mean±SD):

  • Weight (kg): 87.7±21.1
  • BMI: 33.6 ±7.2
  • DXA (% body fat): 45 (range 36-60)
  • Skin fold (% body fat): 45 (range 33-61)
  • Total cholesterol (mg/dL): 172±29.9
  • HDL cholesterol (mg/dL): 51±18.1
  • Systolic blood pressure (mmHg): 116±11.7
  • Diastolic blood pressure (mmHg): 74±8.6
  • VO2 max (ml/kg/minute): 33.8±6.2

Two groups significantly different on HDL cholesterol and diastolic blood pressure only

 Location: Four housing developments, inner city, Atlanta, GA

Summary of Results:

Psychosocial Outcomes

  • High attenders exhibited significantly greater nutrition knowledge scores (71 vs 59, P=0.001).
  • High attenders reported significantly more low-fat practices (40.5 vs 36.9, P=0.05).
  • High attenders were significantly more likely to perceive positive dietary changes (6.4 vs 3.9, P=0.04).
  • High attenders also reported more social support from friends and family for making diet and exercise changes (2.3 vs 2.1, P=0.05).
  • None of the other psychosocial variables differed significantly between the two groups.

Dietary Outcomes

  • High attenders reported substantially lower total kcals, slightly lower percentage of energy from fat and lower cholesterol and sodium intake at posttest compared with low attenders. While in the favorable direction, none of these differences achieved statistical significance.
  • The direction of change within and between groups for percentage calories from fat, fiber and sodium were inconsistent across the two assessment methods.

Anthropometric & Physiologic Outcomes

  • No significant differences were observed between high and low attenders for any of the physical measures. Slight trend favoring high attenders for most measures.
  • Both groups showed an increase in body weight and BMI.
  • High attenders showed a small decrease in body fat (both by skinfold estimation and DXA) and an increase in HDL cholesterol, whereas low attenders showed a slight increase in these adiposity measures and a decrease in HDL cholesterol.
  • Both groups showed a decline in total cholesterol and systolic blood pressure.
  • Eight percent of the sample reported being "a little overweight", 5% "just about right", 48% "a little overweight" and 38% "very overweight". Perceived weight was significantly correlated with baseline BMI (P=0.01).
  • Degree of perceived overweight was correlated with change in BMI (P=0.01). Participants who perceived themselves as heavier at baseline showed a greater decrease in BMI between baseline and posttest.

Other findings

  • On average participants attended 43% of the sessions.
  • Drop out rate (defined as missing the final six sessions) was approximately 45%.
Author Conclusion:
Practitioners are encouraged to apply the principles and procedures from the GO GIRLS! Project to other community-based institutions, as well as clinical and school settings.
Funding Source:
Government: CDC
Reviewer Comments:
  • No control group. In the absence of a control group, results were compared for high and low attenders (the former defined as attending at least 50% of the sessions). The use of 50% attendance as the cut-off for “high attendance” was somewhat arbitrary.
  • Relatively small sample size translates into low statistical power.
  • Attendance and retention were somewhat problematic – on average, participants attended 43% of the sessions and the drop-out rate (defined as missing the final 6 sessions was ~ 45%).
  • With regard to program effectiveness, the results were not encouraging.
  • Participants appeared to express an awareness that they did not fully commit to making the requisite changes.
  • Several of the outcome measures were developed anew for this study or had not been used previously among this population.
  • Two methods of dietary assessment made interpretation of the findings difficult.
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.) 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? No
  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? N/A
5. Was blinding used to prevent introduction of bias? Yes
  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.) Yes
  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? 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? 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)? 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? 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