Quality Health Education Increases Students’
Nutritional Knowledge and Behaviors
Mariane Fahlman, Nate McCaughtry, Jeffrey Martin, Bo Shen, Sara Flory, Amy Tischler
Wayne State University College of Education Division of Kinesiology, Health and Sport Studies
DATA ANALYSIS:
ABSTRACT:
METHODS:
Introduction: Some of the risk factors identified by the Centers for Disease Control most
strongly related to morbidity and mortality are unhealthy dietary behaviors and schools are
an ideal site for targeted interventions. Early research suggests that school interventions
may improve student knowledge, efficacy and behaviors regarding healthier eating.
Purpose: This research was part of a multi-year project to decrease nutritional risk factors
in middle school children by determining the impact of a quality nutrition curriculum, taught
by trained teachers, on children’s nutritional knowledge, behaviors and self-efficacy.
Methods: The study was conducted in a large metropolitan setting and approved by the
IRB. The participants for this study were divided into two groups: an intervention group (n =
1476) and a control group (n = 656). Certified teachers underwent in-service training in the
curriculum, and subsequently taught this curriculum in their health classes to students in the
intervention group. The control teachers and students received no training or intervention. A
43-item valid and reliable questionnaire was used to determine pre-post differences; it
consisted of questions assessing eating habits, knowledge, and self-efficacy. Each set of
questions was totaled giving a subscale score except for the subscale “eating behavior”
which was divided into food groups for analysis. The analysis was conducted using 2-groups
(Intervention vs. Control) by 2-times (pre-post) ANOVA with repeated measures on the time
factor. Results: There were significant group and time main effects and group x time
interaction for self-efficacy and knowledge. As expected, the intervention group scored
higher than the control group at post. There was also a significant group main effect for
eating behaviors. Subsequent post-hoc analysis revealed that the intervention group was
more likely to eat fruits, vegetables and grains, and less likely to eat empty calorie food and
meat than both the control group and their own ‘pre’ score. Conclusion: The results of this
study suggest that a quality nutrition curriculum, delivered by trained professionals, resulted
in significant positive changes in both nutritional knowledge and behaviors in middle school
children. School systems should provide such interventions to their students, given their
potential to significantly impact many aspects of their nutrition.
INSTRUMENT DEVELOPMENT:
The University’s Institutional Review Board approved all aspects of this study. The survey
instrument was developed over the course of one year and involved multiple steps designed
to insure acceptable reliability and validity.
INTRODUCTION:
 Behavioral patterns established in childhood often carry over into adulthood and some of
these are later associated with adult morbidity and mortality
 The quality of the diet of children and adolescents has deteriorated over the past 20
years.
 The decline in diet is closely correlated with an increase in child and adolescent obesity.
 Obese adolescents have an 80 percent chance of becoming obese adults and many of
them carry obesity related morbidities with them into adulthood with grave
consequences.
 With over 53 million students in attendance at schools on a daily basis, the school
system is a perfect vehicle for interventions aimed at children and adolescents.
 In the state of Michigan, nutrition is covered in the health curriculum. Currently, 95
percent of schools report teaching health in grades 6-9 and 90 percent of those schools
report using the Michigan Model® for some aspect of Health.
 The nutrition module for Middle School, “What’s Food Got to Do With It?” is designed to
address “dietary patterns”. The eight lesson plans contain components related to
knowledge such as the food groups, food pyramid, food labels, advertising and body
image. They also contain components specifically designed to target nutritional risk
behaviors such as increasing fruit, vegetable and dairy consumption and healthy eating
at fast food restaurants.
 Previous, published, pilot research on this topic has shown that middle school students
who were taught the Michigan Model® Nutrition Curriculum not only increased their
nutrition knowledge but were more likely to report making changes to their eating habits
that reflect a healthier lifestyle.
PURPOSE:
This research was part of a multi-year project to decrease nutritional risk factors in
middle school children by determining the impact of a quality nutrition curriculum, taught
by trained teachers, on children’s nutritional knowledge, behaviors and self-efficacy.
PHASE 1
1. Development of a questionnaire draft:
Literature Review
Development
of a pool of
items
Consultation
with health
experts N=5
Consultation
with teachers
N=10
Resulted in an 85 question instrument.
PHASE 2
2. Pilot testing of questionnaire and subsequent consultation with teachers
Pilot tested on 120
7th graders
Consultation with teachers
N = 10
 For the behavior questions, the questionnaire presented students with a single serving
picture of different foods based on the food groups. Answers ranged from none to three
or more times and students were asked to indicate how often they ate the pictured food
“yesterday.” Answers were totaled by food group. The total number of servings per food
group was analyzed pre to post.
Table 1. Knowledge and Self-Efficacy Subscale Scores
 The 16 knowledge questions were coded for correct or incorrect answers and the total
number correct was analyzed pre and post intervention.
 A 7-point (1 = not at all confident to 7 = very confident) Likert format was used for the 5
self-efficacy questions. The answers were totaled and the total score was analyzed pre
to post.
 To determine the effects of the curriculum a 2 (pre vs post) by 2 (intervention vs control)
repeated measures analysis of variance was run on each set of subscales. For the
behavior questions, analyses were run on the specific food groups: grains, fruits,
vegetables, dairy products, meats and other. The “other” category was used to describe
foods that that should be eaten on a limited basis and are often referred to as “empty
calorie food” such as donuts, candy or other sweets. When significant Time, Group or
Interaction effects were found, Tukey’s Post Hoc analyses were run to determine where
the individual differences were.
 The statistical package used to run all analysis was SPSS (Ver. 16.0), Chicago, IL.
Statistical significance was set at p < 0.05.
Resulted in more refined a 75 question instrument
PHASE 3 Exploratory Factor Analysis
3. Psychometric Evaluation of Questionnaire Part 1: (N = 161)
Assessing the ability of the questionnaire to
distinguish between subscales with Principles
Component Analysis. (Content Validity)
SUMMARY OF THE RESULTS:
Determining internal consistency
reliability – Cronbach’s Alpha on
subscales
4. Psychometric Evaluation of Questionnaire: Part 2: (N=161)
Concurrent Validity – Dietary
Behavior subset tested against 24Test-retest Reliability
hour recall on 161 Students
Intraclass correlation coefficient test.
(Spearman Rank Order Correlation
Validity)
PHASE 4 Confirmatory Factor Analysis
5. Final Pilot Study
Pilot tested on 783 middle school students of mixed race:
Determining internal
consistency reliability –
Cronbach’s Alpha on
subscales
Pre - Intervention
Post - Intervention
Intervention
Control
Intervention
Control
Subscale
Mean + SD
Mean + SD
Mean + SD
Mean + SD
p
Knowledge
(percent correct)
37 + 81
35 + 8
62 + 81,2
35 + 82
<.001
Self Efficacy
(scale =
5[low] – 35[high])
17 + 51
20 + 3
28 + 31,2
20 + 52
<.001
Scores = Mean + SD. Like numbers represent significant difference pre to post and/or intervention to
control.
DICUSSION:
 The most important finding of this pilot study is that middle school students who were
taught the Michigan Model® Nutrition Curriculum not only increased their nutrition
knowledge but were more likely to report making changes to their eating habits that
reflect a healthier lifestyle.
Students in the intervention group demonstrated the following significant improvements pre
to post:
 The results of this study suggest that a quality nutrition curriculum, delivered by trained
professionals, resulted in significant positive changes in both nutritional knowledge and
behaviors in middle school children
BEHAVIOR:
More likely to eat fruits, vegetables and grains
Less likely to eat meat
Decreased consumption of “other” at post
 School systems should provide such interventions to their students, given their potential
to significantly impact many aspects of their nutrition.
KNOWLEDGE SUBSCALES:
Significant difference pre-post
Higher score at post than controls
LIMITATIONS:
SELF-EFFICACY:
Significant difference pre-post
Higher score at post than controls
Resulted in a 69 question instrument
Assessing the ability of the
questionnaire to distinguish
between subscales with
Principles Component Analysis
(Content Validity)
SUMMARY OF THE RESULTS (CONT.):
While the students who participated in this study are characteristic of other metropolitan
students, the results cannot be generalized to all middle school students.
Table 1. Number of Servings per Food Group.
Intraclass
correlation
Coefficient
testing
Resulted in a valid and reliable 43 question instrument with four subscales
INTERVENTION:
The intervention took place in March of 2006 and 2007. Teachers who were going to be
conducting the intervention in their classrooms participated in eight hours of in-service
training on the Middle School Nutrition book: “What’s Food Got to Do With It?” (Michigan
Model®). Research assistants conducted the pre-assessment and then teachers taught
the lessons over the course of one month. The lessons contained material on the
contents and benefits of the food groups, eating based on the food groups, reading food
labels, body image and surviving fast food restaurants and the school cafeteria. Upon
completion of the unit, research assistants administered the post-assessment.
Pre - Intervention
Post - Intervention
Intervention
Control
Intervention
Control
N = 1476
N = 656
N = 1476
N = 656
Mean + SD
Mean + SD
Mean + SD
Mean + SD
Grains
2.861 + 2.1
2.89 + 1.7
3.651,2 + 2.0
2.522 + 1.9
<.001
Fruits
2.481 +
1.8
2.52 + 1.5
3.251,2 +
2.412 +
1.0
.027
Vegetables
1.311 + 1.1
1.38 + 1.4
2.831,2 + 1.2
1.322 + 2.4
.018
Dairy
2.72 + 1.6
2.99 + 1.6
2.95 + 1.7
2.92 + 1.7
.260
Meats
2.081 + 1.7
2.11 + 1.9
1.1212 + 1.7
3.162 + 1.9
<.001
Other
5.91 + 2.8
5.2 + 3.3
5.91,2 + 2.7
5.02 + 3.0
.025
Food Group
0.7
Like Numbers represent significant difference pre to post and/or intervention to control.
p
ACKNOWLEDGEMENTS:
This study was conducted as part of a larger project called the Detroit Healthy Youth
Initiative funded by a Carol M. White Physical Education Program (PEP) grant. The
contents of this report were developed under a grant from the Department of Education.
However, those contents do not necessarily represent the policy of the Department of
Education, and you should not assume endorsement by the Federal Government.