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Citation:

Panunzio MF, Antoniciello A, Pisano A, Dalton S. Nutrition education intervention by teachers may promote fruit and vegetable consumption in Italian students. Nutrition Research. 2007; 27(9): 524-528.

Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
POSITIVE: See Research Design and Implementation Criteria Checklist below.
Research Purpose:

To evaluate the effectiveness of a classroom intervention by the teacher(s) compared to a nutritionist intervention in promoting fruit and vegetable consumption in elementary school-age children. 

Inclusion Criteria:
  • 20 fourth-grade elementary classes enrolling 521 students were randomly assigned to one of the two nutrition education interventions
  • 10 classes were assigned to each intervention (254 in the teacher intervention and 267 in the nutritionist intervention)
  • 30 teachers (three from each class) participated in the teacher intervention; the same team of six nutritionists participated in both interventions
  • All schools were located in the Foggia Local Health Authority FG/3 in southern Italy.

 

Exclusion Criteria:
  • Fourth-grade classrooms not randomly selected
  • Children younger than eight years and older than 11 years
  • Children attending full-time school (8:30 A.M. to 4:30 P.M.)
  • Previous participation in health promotion programs
  • Children with serious chronic illness.
Description of Study Protocol:

Recruitment

Recruitment began is June 2003. No other recruitment data is given.

Design

The design of the study was group randomized controlled trial. Two fourth-grade classrooms in each of 10 schools were randomly assigned to one of two interventions:

  • Teachers participated in a 12-week nutritional training course and, during the following 12 weeks, conducted the educational dietary program with application activities in their classes (teacher intervention)
  • A team of nutritionists provided the educational dietary program directly to children in their classrooms for 12 weeks (nutrition information) followed by 12 weeks of food and nutrition application activities (nutritionist intervention). 

Dietary Intake/Dietary Assessment Methodology

  • Children participating in both interventions recorded their daily food and snack consumption throughout the 24-week intervention and for an additional 12 weeks
  • Changes in consumption of fruit, vegetables, legumes, chips and sugar-sweetened drinks was noted. body mass index (BMI) and percentage of obesity was also assessed.

Intervention 

  • Teacher intervention: Students were provided nutrition education by teachers trained by nutritionists to improve the dietary habits of children
  • Nutritionist intervention: Students were provided nutrition education by nutritionists. 

Statistical Analysis

  • Categorical variables were compared with the use of the χ2 test or Fisher exact test and continuous variables with the use of independent Student T-tests
  • Differences in proportion and odds ratios (OR) were calculated from contingency tables
  • All statistical tests were two-sided. P>0.05 was considered moderately significant; P>0.001 was considered highly significant.
Data Collection Summary:

Timing of Measurements

Food group frequencies were determined for each 12-week period (number of dietary portions in the reference period divided by 12). The participants also filled out a daily diary in which they noted the hours of physical activity spent in sports outside of school, such as soccer, basketball, volleyball, swimming and dance. Children participating in both interventions recorded their daily food and snack consumption throughout the 24-week intervention and for an additional 12 weeks. Additionally, each child's height and weight were measured at the beginning and end of the 36-week study.

Dependent Variables

  • Variable 1: Fruit, vegetable, legume chips and sugar-sweetened drink consumption
  • Variable 2: BMI and percentage of obesity of subjects.

Independent Variables

  • Teacher Intervention:
    • During the first 12 weeks, teachers took part in a nutrition training course (one two-hour meeting per week) designed  to improve the dietary habits of children. The course consisted of:
      • Nutrition topics including macronutrients and micronutrients, digestion, nutritional needs in the school age, obesity and physical activity
      • Communication guidelines and strategies to modify dietary habits. They were provided the book, How to Correctly Nourish Children: A Guide for Students, Teachers and Parents
    • During the following 12 weeks (second period) teachers participated in 12 two-hour meetings based on the same themes emphasizing nutrition teaching aids such as posters, songs, poems, and stories thus simulating the lessons to give their students
    • During the third period (final 12 weeks), no meetings were held. The lessons continued in the classroom by the teachers for 12 additional weeks. Teachers integrated the nutrition concepts in all of the lessons (math, geography and so on) rather than only in a specific nutrition lesson such as that provided by the nutritionist.
  • Nutritionist intervention:
    • During the first 12 weeks (first period), a team of nutritionists took the teacher's place in the classes and directly taught the students two hours once a week. Topics included  macronutrients and micronutrients, digestion, nutritional needs at the school age, obesity and physical activity. Each child was given the book, How to Correctly Nourish Children: A Guide for Students, Teachers and Parents
    • During the following 12 weeks (second period), the team of nutritionists again taught the students two hours once a week on the same themes as the first period, with applications of making posters, songs, poems and stories
    • During the third period (final 12 weeks), no meetings were held (control period).

Control Variables

During the third period (final 12 weeks) of the nutritionist intervention group, no meetings were held (control period). 

Description of Actual Data Sample:
  • Initial N: 521 students were assigned to one of two nutrition education interventions
    • 254 in the teacher intervention
    •  267 in the nutritionist intervention
  • Attrition (final N): The total students completing the study were 471
    • 228 (10 classes) in the teacher intervention
    • 243 (10 classes) in the nutritionist intervention
  • Age: Fourth-grade elementary children between eight and 11 years old
  • Anthropometrics: Baseline data report no differences for percentage of:
    • Gender
    • Age
    • BMI
    • Percentage of obesity.
  • Location: Foggia, Italy.
Summary of Results:
Comparison Portions of Food Treatment Difference [%(95% CI)] Odds Ratio (95% CI)
Third period vs. second period Fruit (more than one portion per day)  −19.7 (−28.8 to −11.5)  0.4 (0.2 to 0.7)*
Vegetables (more than one portion per day)  −37.9 (−49.1 to −28.6) 0.7 (0.3 to 0.8)*
Legumes (more than one portion per day) 33.0 (−41.7 to −19.9)

0.6 (0.4-0.8)*
 

Chips (more than one portion per day) 25.5 (19.3 to 42.1) 2.5 (1.6 to 3.3)*
Sugar-sweetened drink (more than one portion per day)  29.4 (16.6 to 35.8)
 

2.2 (1.8 to 3.5)*


* P<0.0001.

Other Findings:

  • The children in the teacher intervention reported a constant increase in the consumption of fruit, vegetables and legumes from period one through period three and a constant decrease during the three periods in the consumption of chips and sugar-sweetened drinks
  • The children in the nutritionist intervention group reported an increase in the consumption of fruit and vegetables in the second period compared to the first and a decline in the third period
  • Results for consumption of chips and sugar-sweetened drink were mirror-like compared to the teacher intervention (no change in the first period, a decrease in the second period with respect to the first, followed by an increase in the third period)
  • There was a significant increase in hours spent in physical activity per week for both girls and boys in the teacher intervention group and a non-significant decrease for children
    in the nutritionist intervention group. In particular, the mean of hours spent for physical activity per week:
    • The teacher intervention group raised from 3.2 (±1.7 SD) in the first period to 5.0 (±1.3 SD) in the third period for boys (P<0.0001)
    • The teacher intervention group raised from 5.0 (±1.2 SD) in the first period to 6.0 (SD, 1.7) in the third period for girls (P<0.0001)
    • The mean hours spent for physical activity per week in the teacher intervention group decreased from 3.8 (±1.3 SD) in the first period to 3.3 (±1.7 SD) in the third period for boys (P=0.013)
    • The mean hours spent for physical activity per week in the teacher intervention group decreased from 4.6 (±1.1 SD) in the first period to 4.3 (SD, 1.2) in the third period for girls (P=0.037)
  • Among children in the teacher intervention, the BMI (kg/m2) of both boys and girls and the percentage of obese children did not change significantly. In particular:
    • The mean of BMI slightly raised from 19.6 (±1.5 SD) at baseline to 19.8 (±1.4 SD) at the end study among boys (P=0.317), while it rose from 20.8 (±1.9 SD) to 20.6 (±1.8 SD) among girls (P=0.399)
    • In the same intervention group, the percentage of obesity subjects declined from 15.1% at baseline to 11.1% at the end of the study (P=0.424) for boys and from 17.8% at baseline to 14.2% at the end of the study (P=0.485) for girls
  • In the nutritionist intervention group, children's BMI and the percentage of obese girls and boys increased significantly. In particular:
    • The mean of BMI raised from 19.8 (±1.3 SD) at baseline to 20.4 (±1.4 SD) at the end of the study among boys (P < .0001) and from 20.7 (±1.7 SD) to 21.5 (±1.4 SD) among girls (P <.0001)
    • The percentage of obesity subjects in the same intervention group raised from 14.9% at baseline to 20.5% at the end of the study (P=0.051) for boys and from 16.3% at baseline to 21.9% at the end of the study (P=0.034) for girls. 
Author Conclusion:
  • The results indicated that teacher intervention (dietary education provided by teachers) was superior to nutritionist intervention (dietary education provided by a team of nutritionists directly to the students)
  • An analysis of the results indicates that during the first and second periods, there were no variations in children's food consumption between the two interventions. However, during the third period (that of monitoring without intervention), the results are significantly different. The children in the nutritionist intervention group tended to return to their dietary habits of the first period. In addition, these children, compared to those in the teacher intervention, did not increase hours of physical activity. These two factors may be related to the significant increase in the percentage of obese children in the nutritionist intervention at the end of the study, compared to no significant change in the teacher intervention
  • The results of this study may be explained by the teacher's greater authority compared to an outside expert such as a nutritionist. The results also suggested the possibility of involving parents in the development of the project “Bring some fruit to school,” in accordance with other research
  • Should the results of this work be confirmed by other studies, they emphasize that the role of the teacher is central in dietary education and changing food choices.
Reviewer Comments:

A discussion of reason for and characteristics of attrition would have been appropriate.


 

 

Research Design and Implementation 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 nutrition or dietetics practice?
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 used? (Concurrent preferred over historical controls.)
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 or cross-sectional 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. Criterion may not be applicable in some cross-sectional studies.)
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?
No
  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%.)
No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for?
No
  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?
Yes
  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?
N/A
  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?
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)?
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?
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