Adult Weight Management

AWM: Nutrition Education (2006)


Miller CK, Jensen GL, Achterberg CL.  Evaluation of a food label nutrition intervention for women with type 2 diabetes mellitus.  J Am Diet Assoc 1999; 99(3): 323-328.

PubMed ID: 10076584
Study Design:
Randomized Controlled Trial
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To evaluate an educational intervention about the food label designed specifically for women with type 2 diabetes mellitus.
Inclusion Criteria:
Women aged 40 - 60 years with type 2 diabetes, as label reading habits of women over 65+ differ from those of younger women.
Exclusion Criteria:
Excluded if not included above.
Description of Study Protocol:


Recruited through advertisements in newspapers, public service announcements on tv, an existing community diabetes support group, an outpatient general medicine clinic, and referrals from other participants. 


Pretest-posttest control group design with participants receiving random assignment through random numbers table.

Blinding used (if applicable)

Not used.

Intervention (if applicable)

9 weekly group sessions, 90 minutes each.

Statistical Analysis

Chi-square used to analyze discrete variables.  Analysis of continuous variables using t test.  ANOVA performed to compare groups.  Paired t tests compared pretest and posttest results.  Level of significance was 0.01.

Data Collection Summary:

Timing of Measurements

Pretest and posttest questionnaires after 9 weeks of group sessions.

Dependent Variables

  • Effectiveness of food label education program on participants' knowledge was determined using multiple-choice test designed to measure declarative and procedural knowledge
  • Skills inventory assessed perceived confidence in using the food label.  Face validity, content validity and internal consistency had been established previously. 

Independent Variables

  • Participation in 9 weekly sessions led by same RD

Control Variables


Description of Actual Data Sample:

Initial N: 53 were recruited and were screened.  49 were eligible and 1 declined to participate.  48 randomly assigned.  5 withdrew due to dissatisfaction with assignment.  43 women obtained, 21 in experimental.

Attrition (final N):  40 women completed (93%) the program, 22 controls, 18 experimental

Age:  Controls:  51.4 +/- 6.7 years, Experimental:  51.3 +/- 6.2 years 

Ethnicity:  38 (95%) of subjects were white, 1 African American, 1 Asian. 

Other relevant demographics:  Controls BMI: 32.1 +/- 7.1, Experimental BMI:  33.2 +/- 5.0

Anthropometrics:  No significant differences between experimental and control groups for any variable measured, except that more women in experimental group managed their diabetes through diet only (P < 0.01).

Location:  rural Pennsylvania 


Summary of Results:

Other Findings

Pretest knowledge score between groups were not significantly different (P > 0.01).

Experimental group showed a greater gain than the control group in total knowledge (P < 0.001), declarative knowledge (P < 0.001), and procedural knowledge (P < 0.01) at posttest. 

Posttest data showed a significant increase (P < 0.01) in experimental participants' perceived confidence in using the food label to make product selections.

Author Conclusion:
Women with diabetes need more education about the food label.  This intervention is an effective outpatient education program and educational programs should emphasize both declarative and procedural knowledge.  Participant knowledge and perceived confidence in using the food label improved significantly as a result of the intervention.  Future research should assess retention of knowledge gained and the impact of the intervention on metabolic measures of diabetes management and control.
Funding Source:
Foundation associated with industry:
Reviewer Comments:
Reliability and validity of instruments had been established previously.  Relatively small number of subjects in each group.  Not generalizable to US population.
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? ???
  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? ???
  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? ???
3. Were study groups comparable? ???
  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? ???
  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%.) 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? 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? 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? 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)? N/A
  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? 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