Adult Weight Management

AWM: Nutrition Education (2006)


Smith SC, Taylor JG, Stephen AM.  Use of food labels and beliefs about diet-disease relationships among university students.  Public Health Nutr 2000; 3(2): 175-182.

PubMed ID: 10948384
Study Design:
Cross-Sectional Study
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To measure the reported use of nutrition information on food labels by a population of university students and to determine if label users differed from non-users in terms of gender and specific beliefs related to label information and diet-disease relationships, specifically fat and heart disease and fiber and cancer.
Inclusion Criteria:

University students.

Exclusion Criteria:
None specifically mentioned.
Description of Study Protocol:


University students from randomly selected classes in the College of Arts and Science.  A single-stage cluster sampling technique was used.


Cross-sectional study.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

Self-administered, validated questionnaire.

Statistical Analysis

Belief scores were treated as interval data.  Differences in belief scores were examined using multivariate ANOVA, specifically Pillai's criterion.

Data Collection Summary:

Timing of Measurements

Self-administered questionnaire.

Dependent Variables

  • Food label use:  based on 1995 Health and Diet Survey, asked about use of nutrition info on food labels when purchasing an item for the first time, beliefs about the importance and perceived truthfulness of nutrition information on food labels, beliefs about the existence of diet-disease relationships, based on Thurstone scales of equal appearing intervals of 1-7.  14-day test-retest survey was conducted to determine reliability

Independent Variables

  • Demographic info:  sex, age, degree

Control Variables


Description of Actual Data Sample:

Initial N: 553 students, 51.5% male, 46.8% female

Attrition (final N):  See above

Age:  0.4% <18 years, 44.1% 18 - 20 years, 36.0% 21 - 24 years, 12.1% 25 - 34 years, 5.6% 35 - 54 years, and 0.2% > 55 years.  

Ethnicity: Not specifically mentioned

Other relevant demographics: None mentioned

Anthropometrics:  Did not provide info about similarity of gender groups

Location:  University of Saskatchewan, Canada


Summary of Results:

Other Findings

There were approximately equal numbers of label users and non-users among males (48.6% vs 51.4%), while label users outnumbered non-users by almost 4:1 among females (78.8% vs 21.2%).

The "importance of nutrition information on food labels when making food choices" was the only belief that differed significantly between label users and non-users for both sexes (belief scores for men:  4.17 for label users, 3.13 for non-users, P < 0.05; belief scores for women:  4.11 for label users, 3.39 for non-users, P < 0.05).

For females, no other beliefs distinguished label users from non-users.

However, for males, significant differences were found between label users and non-users on the beliefs that nutrition information is truthful and that a relationship between fiber and cancer exists (belief scores 3.71 for label users, 3.49 for non-users, P < 0.05).

Author Conclusion:
Females appear to use food labels more often than do males.  The only consistently observed difference between label users and non-users (male and female) was that users believed in the importance of nutrition information on food labels while non-users did not.
Funding Source:
University/Hospital: University of Saskatchewan (CA)
Foundation associated with industry:
Reviewer Comments:
Questionnaire tested for validity and reliability.  Not generalizable.
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? No
  2.2. Were criteria applied equally to all study groups? ???
  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) N/A
  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? ???
  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.) ???
  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? N/A
  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? 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? 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? ???
  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