Nutrition Literacy and Food Practices of Preschool Teachers in Greece

Abstract

Background: Nutrition literacy, defined as “the skills to comprehend and implement nutrition information into everyday practice”, is a new area of study. Preschool teachers affect children’s perception of nutrition and health and contribute to their nutrition literacy skills. Objective: This cross-sectional study aimed to assess the level of nutrition literacy (NLS-Gr) of preschool teachers. Methods: The research included two stages of cluster sampling in a sample of kindergarten teachers in Greece (Rhodes Island). Nutrition literacy was assessed with the NLS-Gr, the Greek version of the NLS, and adherence to a Mediterranean diet with the MedDiet score. Results: The mean NLS-Gr score was 25.87 (SD ± 2.2) and is considered adequate. The correct answers range from 65.1% to 100%. The MedDiet score was calculated at 33.94 (SD ± 3.8), and no correlation was found between the MedDiet score and the NLS-Gr. The NLS-Gr score of kindergarten teachers was adequate, higher than that of previous research on different populations. Conclusions: The study concluded that adherence to the Mediterranean diet requires improvement, and food waste needs to be reduced. Educators should be empowered through targeted educational interventions to improve their dietary habits and, therefore, enhance students’ health and nutritional behaviors. Further research is needed to contribute to formulating nutrition strategies and policies in kindergarten.

1. Introduction

Modern technological advancements and large-scale industrialization have drastically altered agricultural practices, resulting in increased food production, a global trade network, and a surge in processed foods [1]. While this has led to positive outcomes such as an increase in life expectancy, it has also contributed to a decline in dietary quality, becoming a primary factor in the global disease burden. A significant portion of the world’s population currently experiences various forms of malnutrition, including undernutrition, micronutrient deficiencies, overweight, obesity, and related non-communicable diseases [2]. In many developing nations, children face a “double burden” of malnutrition, experiencing simultaneously the challenges of undernutrition (such as stunting and wasting) and the increasing prevalence of overweight and obesity. This double burden significantly impacts their health and cognitive abilities [3]. Furthermore, climate change threatens ecosystems, biodiversity, agricultural production, and food security, while population growth intensifies food security challenges [4].

Under these circumstances, in the last decades, new concepts have emerged in research and policy, such as “health literacy” and the related terms “nutrition literacy” and “food literacy” [5]. “Nutrition literacy” is defined as “the degree to which individuals can obtain, process, and understand basic nutrition information and nutrition services they need to make appropriate nutritional decisions” [6,7]. Furthermore, there is evidence that nutrition literacy is critical for better nutritional habits and overall diet [8,9]. Adherence to a balanced diet is positively associated with higher nutrition and food literacy skills [10]. Other researchers suggest that nutrition literacy predicts adherence to healthy/unhealthy diet patterns [9]. The tools intended for nutrition literacy assessment focus primarily on functional nutrition literacy [11], even though some researchers [12] developed a critical nutrition literacy scale and highlighted the importance of skills beyond basic knowledge, such as effectively communicating about nutrition and acting within social contexts to overcome barriers to healthy eating. Naigaga et al. [13] emphasize that the two aspects of critical nutrition literacy, namely “critical evaluation of nutrition information” and “engagement in dietary behavior”, are linked at a personal level.

However, there has not yet been a consensus among researchers about one generic method of measuring health and nutrition literacy [11,14]. Vamos et al. and Nutbeam [15,16] share a similar perspective, asserting that health literacy skills continuously evolve, enrich, and develop throughout individuals’ lives within diverse and rapidly changing environments and contexts. It represents a continuous and lifelong learning process and qualitative education that is essential for achieving health literacy across different groups. Therefore, nutrition literacy is interconnected with social institutions, such as schools, families, and the welfare state, aiming at the health promotion of individuals, families, and communities throughout their lifespan [17].

Research on nutrition literacy in Mediterranean countries is limited. Mohsen et al. [18] conducted research on food and nutrition literacy in the Middle East and North Africa, including countries of the Mediterranean (e.g., Lebanon, Morocco, Syria, etc.). In some of these countries, nutrition literacy was assessed. In this research, the participants were insufficiently literate in food and nutrition, especially regarding their skills rather than their cognitive domain [18].

In Greece, even though the national dietary guidelines provide a nutritional framework for the Greek population based on age, to our knowledge, there is no official national policy for improving the health and nutrition literacy of the population [19]. Limited studies about nutrition literacy were conducted recently in the Greek population [20,21]. In a study of the Greek population, better parental feeding practices were significantly and positively associated with higher levels of parents’ health and nutrition literacy [22].

Schools, as prominent social institutions, play a crucial role in shaping children’s educational and nutritional experiences. Nutrition education in the school context significantly affects the health and well-being of students during their childhood and later stages of life [23]. In school-based programs, teachers have a critical role in implementing educational materials and innovative practices about health and nutrition literacy. Effective nutrition education interventions in school settings are long-lasting and comprehensive and consider the students’ social environment, such as family, other students and classmates, teachers, and the local community [24,25]. Research also suggests that such interventions are effective when they are based on best evidence-based practices and included in the school curricula and everyday activities [26].

In Greece, nutrition policy during the preschool years has many discrepancies in its overall structure. For instance, in public kindergarten, families are responsible for the meals of the preschoolers (preparation, cost, etc.), and teachers are responsible for advocating nutrition education for preschoolers and, consequently, for their parents. A comparative analysis of nutrition education in Greece against other nations like Sweden and the USA exposes notable shortcomings in educational nutrition strategies. Beneficial practices in dietary education for students should be implemented in Greece under economic and social circumstances [27].

Empowering preschool teachers to advocate for nutrition education and health promotion initiatives for preschoolers is crucial [24]. They play a pivotal role in implementing nutritional educational materials within the curriculum, regardless of the level of detail provided. Teachers, especially, have a distinct opportunity to design and execute inventive programs to meet students’ health and educational requirements. They can offer formal and informal educational experiences focused on healthy eating and lifestyles to prevent obesity [28,29]. Educators should be empowered to promote nutrition education and health promotion programs for students. They are a key factor in implementing educational materials for nutrition included in the curriculum, whether detailed or not [24].

The present study aims to assess the level of nutrition literacy of preschool teachers and their adherence to the Mediterranean diet in the context of sustainable kindergarten in Greece. Even though the role of preschool teachers in students’ nutrition education is robust, a gap exists in the literature regarding the impact of empowering teachers as change agents in delivering integrated nutrition knowledge into core subjects. Measuring the teachers’ nutrition literacy could contribute to research development about nutrition policy formulation in kindergarten and prevent nutritional deficiencies and excess weight in young children. To the best of our knowledge, this is the first research conducted in this population group to date, and it could contribute to promoting nutrition education for preschoolers and improving their dietary habits in the context of health-promoting schools.

2. Materials and Methods

2.1. Ethical Aspects

The University of the Aegean approved the study protocol with the approval decision 690/18 March 2021. The research complies with the ethical rules and principles of the Ethics and Deontology Committee of the University of the Aegean and according to the University’s Code of Ethics and Deontology of Research. The participants were informed about the study and its purpose via email. Participation in the research was voluntary. The confidentiality of their responses was also emphasized, ensuring their information was used solely for research purposes and protected from unauthorized access.

2.2. Subjects and Criteria for Participation in the Study

The research was conducted during the school year 2021–2022. The data collection commenced in November 2021 and was completed in February 2022. The questionnaire was online and anonymous and included anthropometric measures like height and weight. Preschool teachers self-reported data on anthropometric measurements. BMI was calculated as weight/height² (kg/m²). Specific criteria of inclusion and exclusion for participation in the study were applied. The study included kindergarten teachers working in public schools on the island of Rhodes. In contrast, kindergarten teachers from private schools were excluded from the research due to significant differences in nutrition policies. In private institutions, meals are prepared by external companies, which limits the ability of both preschool teachers and parents to participate in meal selection. Therefore, kindergarten teachers in private schools do not play a significant role in the nutritional education of parents and children. In public kindergartens, however, teachers actively educate parents and children about healthy nutrition. They can suggest nutritional guidelines, and parents are typically responsible for preparing snacks and lunches for their children. Preschool teachers who were not employed in any kindergarten were also excluded. Participants were informed about the questionnaire via email, and the completion was conducted online. The questionnaire was not distributed on social media to omit answers from non-kindergarten teachers. Additionally, the researcher communicated with the kindergarten principals multiple times to ensure better response rates and informed the entire population of kindergarten teachers. The research was conducted when various COVID-19 containment measures were implemented and prohibited the physical presence of researchers in schools.

2.3. Study Design

The present study is cross-sectional. Before officially distributing the survey, a pilot study involving 20 individuals was conducted. The distribution, data collection, and analysis processes were thoroughly tested. A total of 149 kindergarten teachers serving in public schools on the island of Rhodes, out of a total of 228, participated in the research. The sample selection included the two-stage cluster sampling method. This probability sampling method divides the target population into groups, such as regions or schools [30]. This specific type of sampling was carried out in two stages. In the first stage, the clusters (schools) were sampled, and in the second stage, the participants (kindergarten teachers) were selected from each cluster (school). In the present research, the kindergartens on the island of Rhodes represent the clusters, and the kindergarten teachers participate in each cluster.

2.4. Sample Size

The sample size was initially approached according to simple random sampling. This means that each member of the population of preschool teachers must have the same probability as the rest of the members to be selected in the sample. Specifically, for a Type I error of 5%, a confidence interval of 95%, a population size of 228 preschool teachers on the island of Rhodes, and a response distribution of 50%, it was found that the required sample size is 143 individuals. The above method is integrated into various available online tools, such as https://www.calculator.net/sample-size-calculator.html (accessed on 12 January 2015) and http://www.raosoft.com/samplesize.html (accessed on 12 January 2025), and others [31].

The usual sample size estimates assume the independence of observations. Clustering involves designing choices made by the researcher to avoid the phenomenon called contamination. Even in cases where the risk of contamination is possible, randomizing the sample can be a suitable choice in research design aimed at estimating the effect of a factor under real-world conditions [32]. During research design, increasing the number of clusters (kindergartens) may increase the power of the study more than increasing the elements within the clusters (teachers). Fixed formulas can be used for sample size, but to determine the effective sample size, adjustments should be made using the design effect to find the required sample size [33,34,35]. The intraclass correlation coefficient (ICC) is a measure of correlation within clusters. In studies involving human subjects, it is usually small, but the design effect is magnified by the number of elements within the cluster (m). The smaller the design effect, the greater the efficiency of the sample size [33]. Therefore, the initial sample of 143 kindergarten teachers should be increased by 2.8%. Considering all the above, the research sample should be adjusted using the research’s impact and ultimately amount to 147 kindergarten teachers. Additionally, two more questionnaires were added (10% extra), resulting in a final sample size of 149 kindergarten teachers.

2.5. The Questionnaire

Different research tools emerged from the literature review based on research questions for the implementation of the research. A questionnaire consisting of 65 questions was developed, weighted, and included the MedDietScore tool by Panagiotakos et al. [36] and the NLS-GR tool by Michou et al. [37].

The questionnaire intended for preschool teachers included the anthropometric characteristics of the sample (gender, height, weight, and age), adherence to the Mediterranean Diet using the MedDietScore tool, level of physical activity, and sedentary lifestyle, which included four questions about physical activity and sedentary behavior on weekdays and weekends and, lastly, the nutrition literacy scale, which was the NLS-GR tool. The socioeconomic characteristics of the sample included educational level, type of employment, and net family income. An additional question for parents asked whether the children lived with one or both parents.

2.5.1. MedDietScore Tool

Regarding the MedDiet score, a tool for measuring adherence to the Mediterranean Diet was developed by Panagiotakos et al. [38] and has been applied to Greek populations [36,38,39,40]. It is considered a valid and scientifically well-recognized tool for assessing adherence to the Mediterranean Diet according to review studies and comparisons of different tools for assessing Mediterranean Diet adherence in healthy adults [41].

2.5.2. NLS-GR Tool

The Nutrition Literacy Scale for the Greek population (NLS-Gr) is a tool designed to assess the degree to which adults, parents, and educators are sufficiently informed and able to apply their knowledge to make conscientious decisions regarding their nutrition and health. This tool is the Greek version of the NLS tool [42] and includes 29 questions to assess the nutrition literacy of adults [37]. The reliability of the Greek version of the NLS-Gr is tested and is considered a valid tool for measuring nutrition literacy among healthy adult populations with satisfactory psychometric characteristics [37].

2.5.3. Statistical Analysis

Data analysis was performed using the Statistical Package for the Social Sciences 27.0 (SPSS Inc., Chicago, IL, USA). First, the demographic characteristics of participants were described. An independent samples t-test and a one-way ANOVA, as well as the corresponding non-parametric Mann–Whitney U test and Kruskal–Wallis H test, were used to investigate the relationship between the qualitative and quantitative variables. In the case of a statistically significant result in the one-way ANOVA and Kruskal–Wallis tests, repeated tests (post hoc tests) were applied using the Bonferroni correction. In addition, to investigate the relationship between quantitative and ordinal variables, Spearman’s correlation coefficient (rs) was calculated along with 95% confidence intervals (95% CI). Finally, the χ² test (chi-squared test) and Fisher’s exact test (Fisher’s exact test), in case of expected counts (expected counts) lower than 5, were applied to investigate correlations between the qualitative variables. For all tests, p < 0.05 was considered statistically significant. All tests performed were two-sided. For the presentation of the qualitative variables, frequencies were used along with percentages, n (%), and bar graphs. In the quantitative variables, either the mean value with the standard deviation (mean SD) or the median value with the interquartile range (median Q1–Q3) was analyzed, depending on whether the condition of normality was met, as well as boxplots. Normality testing was performed with the Shapiro–Wilk test and appropriate graphs (histograms and Q-Q plots).

3. Results

3.1. Sample Characteristics

The sample consisted of 96% females (143) and 4% males (6). Most preschool teachers, at a percentage of 43.6%, were aged 44–55 years old, 38.3% were aged 33–43 years old, 17.4% were aged 22–32 years old, and 0.7% were older than 56 years old. For detailed information, see the Supplementary Material (Table S1).

3.2. NLS-Gr

The correct answers of kindergarten teachers in the questionnaire about nutrition literacy are shown in

Table 1. Items of the Greek NLS by percentage answered correctly.

Correct Answers of the Greek NLS by Percentage	N (%)
Healthy eating
Healthy eating is really supposed to help our hearts.	146 (98.0)
However, no single food can supply all the nutrients we need.	114 (76.5)
Eating a variety of foods ensures you get all the nutrients needed for good health.	145 (97.3)
Grains, fruits, and vegetables are food groups that form the basis of a healthy diet.	98 (65.8)
For a healthy diet, we are advised to eat five servings of fruits	137 (91.9)
and vegetables each day.	143 (96.0)
Foods like butter have a lot of saturated fat, which can increase cholesterol.	145 (97.3)
We also know that cholesterol can be affected by foods high in trans fatty acids.	125 (83.9)
Experts often say to avoid foods high in trans fatty acids	147 (98.7)
because they are fattening.	147 (98.7)
Nutrition and health
Obesity increases the risk of diseases such as diabetes.	146 (98.0)
Fiber is the part of plant-based foods that your body does not digest and absorb.	142 (95.3)
Whole grains provide more fiber than processed grains.	133 (89.3)
A good diet should contain approximately 25–30 g of fiber a day.	131 (87.9)
Calcium is essential for bone health	149 (100.0)
As you age, your bones may get thinner as minerals are lost.	106 (71.1)
Even in older people, vitamin D is needed to keep bones healthy.	148 (99.3)
Foods with added sugars are sometimes called foods with empty calories.	97 (65.1)
Food safety
To prevent illness from bacteria	124 (83.2)
keep eggs in the refrigerator.	147 (98.7)
Organic food
Farmers who grow organic foods don’t use conventional methods.	137 (91.9)
They control weeds by techniques such as crop rotation rather than pesticides.	135 (90.6)
For this and other reasons, organic food costs more than conventional food.	118 (79.2)
Energy and nutrients
A 180-calorie serving with 10 g of fat has 50% of its calories from fat.	148 (99.3)
A 140-pound (64 kg) woman needs about 51 g of protein daily.	143 (96.0)
Using fat-free mayonnaise on a sandwich can reduce the grams of fat.	107 (71.8)
My doctor told me that “fat-free” is not the same as calorie-free.	138 (92.6)
She also told me to make the size of my portions smaller	132 (88.6)
to help control my weight.	127 (85.2)

. The percentage of correct answers was high, ranging from 65.1% to 100%. The mean score (mean) of the NLS-GR rating for the sample of kindergarten teachers was 25.87 (SD ± 2.203) for the total of 29 questions in the tool. The nutrition literacy level in this research is considered adequate. Scores from 0–7 are categorized as inadequate, 8–14 are marginal, and 15–29 are adequate [42].

3.3. NLS-Gr and Association with Education, Professional Experience, Weight Classification, and Family Income

Table 2. Comparison of NLS-Gr Score across educational level, years of teaching experience, BMI category, and net annual family income.

	Nutrition Literacy/NLS-Gr
	Median (Q1–Q3)	p-Value *
Educational level		0.925
University Degree (BSc)	26 (24–28)
Postgraduate Student	26 (24–27)
Postgraduate Degree Holder	26 (24–27)
PhD Candidate & Doctorate Holder	26.5 (24.5–28)
Years of Teaching Experience
≤1	25.5 (24–27)	0.192
1–10	26 (24–27)
11–15	27 (26–27)
16–20	27 (24.5–28)
>20	26 (25.3–28)
Classification Based on BMI, N (%)
Underweight	24.5 (24–27)	0.227
Normal Weight	26.0 (24.3–27)
Overweight	27 (25.3–28)
Obese	26 (24–27)
Net Annual Family Income
<10,000 €	25 (23.5–27)	0.048 *
10,001–20,000 €	27 (25–28)
20,001–30,000 €	26 (24–28)
>30,000 €	26 (26–27.5)

* Statistical significance p < 0.05, Kruskal–Wallis.

shows the association between nutrition literacy and educational level, years of teaching experience, postgraduate studies, and net annual family income. The comparison of the NLS-Gr scores across different educational levels revealed no significant differences. Moreover, the NLS-Gr scores differed significantly across the net annual family income groups (p-value = 0.048), with the highest median score observed in the EUR 10,001–20,000 category (adj. p-value = 0.043).

Furthermore, the median value of nutrition literacy is lower for individuals with a net annual family income of <10,000 euros, as the median value on the NLS-Gr for this income bracket is 25 (p-value = 0.048, p < 0.05). In contrast, for incomes of 10,001–20,000 euros, it is 27.

3.4. NLS-Gr and Association with Food Practices and Food Waste

The relationship between nutrition literacy and preschool teachers’ perspectives on food rejection, meal planning, organic product consumption, and waste composting is shown in

Table 3. Comparison of NLS-Gr score across food choices and food waste.

	Nutrition Literacy/NLS-Gr
	Median (Q1–Q3)	p-Value
Meal Planning		0.017 *
No	25.5 (24–27)
Yes	27 (25–28)
Shopping List		0.976
No	26.5 (24.0–27.8)
Yes	26 (24–28)
Storage of fruits and vegetables in the refrigerator		0.438
No	25.5 (24.0–27.3)
Yes	26 (24–28)
Food disposal		0.167
never or almost never	27 (25–28)
rarely (a few times a year)	26 (24–27)
sometimes (a few times a month)	27 (24–28)
often (a few times a week)	26 (23.3–27.0)
always (daily)	-
Organic food consumption		0.525
No	26 (24.0–27.5)
Yes	26.5 (24–28)
Composting food waste		0.359
No	26 (24–28)
Yes	26 (23.5–27.0)

* p-value < 0.05.

. A statistically significant correlation was found between nutrition literacy and meal planning. As shown in the table, participants who organize and plan their meals have a higher median NLS score (md = 27) compared to those who do not plan meals (md = 25.5), and this difference is statistically significant (p = 0.017, p < 0.05).

3.5. NLS-Gr and Association with Meddiet Score

There was no statistically significant correlation between nutrition literacy, calculated using the NLS-GR tool, and adherence to the Mediterranean Diet, assessed with the MedDiet score tool. As illustrated in the corresponding scatter plot (Figure 1), a cloud of points is observed around the straight line, indicating no correlation between them. Furthermore, examining the relationship between MedDiet score and NLS-GR using the Spearman coefficient (

Table 4. Correlation between NLS-Gr score and MedDiet score.

	rs	p-Value *
Spearman’s correlation coefficient	0.1 (−0.1, 0.3)	0.202

* p-value < 0.05.

) did not reveal a statistically significant correlation (p-value = 0.202, p > 0.05).

3.6. NLS-Gr and Weight Categories

The comparison of NLS-Gr nutrition literacy across different weight categories, as classified based on body mass index, revealed no statistically significant relationship (p-value = 0.227, p-value > 0.05), as shown in the

Table 5. Comparison of nutrition literacy (NLS-Gr) across body weight categories.

NLS-Gr, Median (Q1–Q3)	Underweight	Normal	Overweight	Obese	p-Value *
	24.5 (24–27)	26 (24.3–27.0)	27 (25.3–28)	26 (24–27)	0.227

* p-value < 0.05.

3.7. Correlation of Adherence to Meddiet and Physical Activity

The non-parametric Spearman’s correlation coefficient was used to examine the associations between the MedDiet components (food groups) and physical activity/sedentary behavior.

Table 6. MedDiet score association with physical activity/sedentary lifestyle.

MedDiet Component	Physical Activity & Sedentary Lifestyle	rs (95% CI)	p-Value
Whole Grains	Sedentary Lifestyle (hours, weekdays)	0.9 (0.8, 0.9)	<0.001
	Sedentary Lifestyle (hours, weekends)	0.0 (−0.1, 0.2)	0.639
	Average Exercise (per day)	0.2 (0.1, 0.4)	0.009
Potatoes	Sedentary Lifestyle (hours, weekdays)	0.0 (−0.1, 0.2)	0.780
	Sedentary Lifestyle (hours, weekends)	0.0 (−0.2, 0.2)	0.798
	Average Exercise (per day)	0.0 (−0.2, 0.2)	0.933
Fruits	Sedentary Lifestyle (hours, weekdays)	0.3 (0.1, 0.4)	0.002
	Sedentary Lifestyle (hours, weekends)	−0.1 (−0.3, 0.1)	0.171
	Average Exercise (per day)	0.2 (0.1, 0.4)	0.009
Vegetables	Sedentary Lifestyle (hours, weekdays)	0.3 (0.2, 0.5)	<0.001
	Sedentary Lifestyle (hours, weekends)	−0.1 (−0.3, 0.1)	0.313
	Average Exercise (per day)	0.1 (0.0, 0.3)	0.087
Legumes	Sedentary Lifestyle (hours, weekdays)	0.1 (0.0, 0.3)	0.093
	Sedentary Lifestyle (hours, weekends)	0.0 (−0.2, 0.2)	0.861
	Average Exercise (per day)	0.1 (0.0, 0.3)	0.105
Fish and Seafood	Sedentary Lifestyle (hours, weekdays)	0.1 (−0.1, 0.3)	0.181
	Sedentary Lifestyle (hours, weekends)	−0.1 (−0.3, 0.0)	0.083
	Average Exercise (per day)	0.2 (0.0, 0.3)	0.067
Red Meat and Meat Products	Sedentary Lifestyle (hours, weekdays)	0.2 (0.0, 0.3)	0.064
	Sedentary Lifestyle (hours, weekends)	−0.1 (−0.2, 0.1)	0.502
	Average Exercise (per day)	0.2 (0.0, 0.3)	0.055
Poultry	Sedentary Lifestyle (hours, weekdays)	0.0 (−0.1, 0.2)	0.655
	Sedentary Lifestyle (hours, weekends)	0.0 (−0.1, 0.2)	0.597
	Average Exercise (per day)	−0.1 (−0.3, 0.1)	0.210
Dairy (Full Fat)	Sedentary Lifestyle (hours, weekdays)	−0.2 (−0.3, 0.0)	0.026
	Sedentary Lifestyle (hours, weekends)	−0.2 (−0.3, 0.0)	0.068
	Average Exercise (per day)	−0.2 (−0.3, 0.0)	0.078
Olive Oil	Sedentary Lifestyle (hours, weekdays)	−0.2 (−0.3, −0.02)	0.025
	Sedentary Lifestyle (hours, weekends)	0.1 (−0.1, 0.2)	0.307
	Average Exercise (per day)	0.0 (−0.2, 0.2)	0.868
Alcohol	Sedentary Lifestyle (hours, weekdays)	−0.1 (−0.3, 0.1)	0.291
	Sedentary Lifestyle (hours, weekends)	0.0 (−0.2, 0.1)	0.679
	Average Exercise (per day)	−0.2 (−0.3, 0.0)	0.057

shows that cereal, fruit, and vegetable consumption was significantly correlated with physical activity levels.

Specifically, the question “How often do you consume unprocessed cereals (whole meal bread, whole meal pasta, unprocessed rice, etc.)” was found to be associated with the questions “How many hours/day do you lead a sedentary lifestyle” and “How many hours do you exercise per day on average” at a statistically significant level. Specifically, as the hours of a sedentary lifestyle increase, the consumption of unprocessed cereals in one week also increases (rs = 0.9, 95% CI 0.8, 0.9). Additionally, as the hours of daily exercise increase on average, the consumption of unprocessed cereals in one week also increases (rs = 0.2, 95% CI 0.1, 0.4).

A similar trend was observed in the kindergarten teachers’ sample regarding weekly fruit consumption. Specifically, it was found that, as the consumption of fruits per week increases, the hours/day of a sedentary lifestyle and the hours of daily exercise on average also increase (rs = 0.3; 95% CI (0.1, 0.4) and rs = 0.2; 95% CI (0.1, 0.4), respectively). Additionally, it was found that the hours/day of sedentary lifestyle on weekdays are positively associated with their weekly consumption of fresh or boiled vegetables (rs = 0.3; 95% CI (0.2, 0.5)). The hours/day of a sedentary lifestyle on weekdays are negatively associated with the consumption of dairy products (rs = −0.2; 95% CI (−0.3, 0.0)). Lastly, the average hours of sedentary lifestyle led by kindergarten teachers on weekdays are negatively associated with frequent olive oil consumption (rs = −0.2; 95% CI (−0.3, −0.02)).

3.8. Food Disposal Practices

According to the teachers’ responses, the leading causes of food rejection are either spoilage before consumption or considering them as leftovers.

Table 7. Food disposal by food categories and causes.

Food Disposal
Food Categories (n)	Spoilage Before Consumption	Expired Date Passed	During Cooking	As Leftovers
	n (%)	n (%)	n (%)	n (%)
Milk-Yogurts (n = 48)	30 (62.5)	27 (56.3)	1 (2.1)	15 (31.3)
Cheese (n = 12)	9 (75.0)	3 (25.0)	1 (8.3)	6 (50.0)
Fruits (n = 43)	29 (67.4)	11 (25.6)	0 (0.0)	23 (53.5)
Vegetables (n = 55)	38 (69.1)	16 (29.1)	0 (0.0)	30 (54.5)
Bread (n = 41)	17 (41.5)	8 (19.5)	1 (2.4)	25 (61.0)
Fats–Oils (n = 17)	7 (41.2)	4 (23.5)	2 (11.8)	13 (76.5)
Soft Drinks (n = 13)	10 (76.9)	8 (61.5)	0 (0.0)	7 (53.8)
Desserts (n = 17)	9 (52.9)	9 (52.9)	0 (0.0)	8 (47.1)
Meat (n = 14)	5 (35.7)	4 (28.6)	2 (14.3)	11 (78.6)
Chicken (n = 6)	4 (66.7)	3 (50.0)	1 (16.7)	4 (66.7)
Fish (n = 2)	2 (100.0)	1 (50.0)	0 (0.0)	1 (50.0)
Eggs (n = 10)	6 (60.0)	5 (50.0)	0 (0.0)	5 (50.0)
Legumes (n = 13)	7 (53.8)	2 (15.4)	2 (15.4)	11 (84.6)
Rice–Pasta (n = 23)	7 (30.4)	1 (4.3)	1 (4.3)	20 (87.0)

shows that the highest percentages are observed in these categories. Teachers could choose more than one type of food, as categorized in the questionnaire. Teachers reported that the foods they mostly discard because of spoilage include vegetables (55 teachers), milk (48 teachers), and fruits (43 teachers), while the less frequently mentioned are chicken (6 teachers) and fish (2 teachers). Foods that teachers stated they mostly reject because they are spoiled were milk and yogurts (62.5%), cheeses (75%), fruits (67.4%), vegetables (69.1%), soft drinks (76.9%), desserts (52.9%), meat (35.7%), fish (100%), and eggs (60%). In contrast, most teachers claimed that they discarded bread (61.0%), fats and oils (76.5%), chicken (66.7%), legumes (84.6%), rice, and pasta (87.0%) as leftovers.

4. Discussion

The assessment of nutrition literacy using the NLS-Gr tool showed that the mean score for the sample of 149 kindergarten teachers was adequate for the overall 29 questions of the tool. In a previous study of Diamond [42] with 341 patients in the US, the NLS tool was used and reported a mean score on the questionnaire of 23.7 (SD ± 4.1). Additionally, research on 1281 adults in the Greek population, applying the NLS-Gr for the first time, the Greek version of the NLS, reported that the mean score of the sample was 22.11 (SD ± 5.67) [43]. According to Sampaio et al. [44], in a study with 38 individuals in Brazil, the mean NLS-Gr score was 22.7 (SD ± 3.9). In general, the NLS score in the present research is adequate and higher than previous studies conducted in Greece or on other populations. In all cases, nutrition literacy is considered sufficient, as the score falls into the category of 15–29 [37].

The participants’ high levels of nutrition literacy may be explained by their higher educational level. However, our study found no statistically significant correlation between participants’ nutrition literacy and holding a postgraduate or doctoral degree. In previous studies, nutrition literacy was higher in individuals with a higher educational level [45]. Additionally, in a study with 1281 adults in Greece, education was positively associated with nutrition literacy, as educated participants had higher nutrition literacy than non-educated ones [43]. Chronic disease is negatively associated with nutrition literacy, and especially nutrition literacy levels in Greeks with chronic disease could help individuals to manage chronic conditions better, thus reducing the overall burden of chronic diseases [46,47,48,49,50].

Numerous studies have associated nutrition literacy and socioeconomic status in different populations [45,46,47,48,49]. Research conducted in the Greek population [45] reported that participants with a medium annual income had significantly higher nutrition literacy than participants with a low annual income. Our findings are in line with this study, as it was found that participants with a low annual income had a lower NLS score than those with a medium income at a statistically significant level.

Basic nutrition knowledge is positively associated with healthier eating habits. Taylor et al. [9] suggest that a more comprehensive understanding of nutrition is a stronger predictor of dietary choices. Inadequate nutrition literacy leads to less-desirable nutritional choices, such as adherence to a Western-type diet, in contrast to high nutrition literacy, which is associated with better dietary habits, such as those found in the Mediterranean diet. A study of Italian adults showed a strong correlation between higher nutrition literacy and adherence to the Mediterranean diet, suggesting that a deeper understanding of nutrition empowers individuals to make healthier food choices [50]. They found a strong association between nutrition literacy and the Mediterranean diet, and there was a clear connection between a healthy dietary pattern and the nutrition literacy of the population.

In contrast, in our study, nutrition literacy (NLS-Gr) was not associated with adherence to the Mediterranean diet. The percentage of correct answers ranged from 65.1% to 100%, and the mean NLS-Gr was adequate, which may explain the lack of a correlation at a statistically significant level between Mediterranean diet adherence and nutrition literacy. Thus, the target population had a higher educational level, contrary to other studies conducted in different populations of various socioeconomic backgrounds.

Our results are in line with previous research. A study on university students in Lisbon showed that, despite having adequate nutrition literacy levels, their adherence to the Mediterranean diet was insufficient [51]. It is important to note that adherence to the Mediterranean diet may differ in various regions due to different motives or attitudes towards the diet [51]. Factors that affect the adoption and adherence to the Mediterranean diet may include financial, cognitive, socio-cultural, lifestyle, accessibility and availability, sensory and hedonic, and demographic circumstances [52]. Our research indicates that nutritional literacy and meal planning are connected, suggesting that knowledge can influence informed dietary choices. Further research, including factors such as limited time or psychological aspects, like stress and motives, could explain this gap between knowledge and adherence to the Mediterranean diet reported in the present study.

Sociodemographic factors, like age, marital status, and education, influence adherence to the Mediterranean diet of patients with diabetes mellitus [53] and healthy populations [54]. Several researchers suggest that physical activity is a good predictor of adherence to the Mediterranean diet [55,56]. Our study revealed that increased physical activity was linked to consuming fruits and unprocessed cereals, key components of the Mediterranean diet. This suggests that individuals prioritizing physical activity may also be more likely to adhere to the Mediterranean diet. Future research using a 7-day physical activity record and incorporating assessments of psychological factors and time constraints could provide a more comprehensive understanding of the factors that affect preschool teachers’ dietary choices and explain the gap between nutrition knowledge and adherence to the Mediterranean diet observed in the present study.

A literature review reported that nutrition literacy interventions positively influence children’s dietary choices and nutrition security. These interventions are most effective when they incorporate technology, use multiple learning modalities, last longer than four weeks, and include face-to-face sessions [57]. Research on teachers’ nutrition knowledge at all educational levels is limited [14,58]. The results of a previous study on teachers in Greece were encouraging because of the improvement in nutrition knowledge after implementing an e-learning program.

It should be noted that this research, to the best of our knowledge, is the first study to focus on nutrition literacy, adherence to the Mediterranean diet, and perspectives about the nutrition of a specific population group in Greece with a high educational level, namely kindergarten teachers, who also affect the nutrition and health literacy of young children. Their nutrition literacy skills are crucial for nutrition education, as research shows that interventions to improve food and nutrition literacy can positively affect food and nutrition skills and dietary patterns and improve diet quality [59]. Kindergarten teachers influence the health of toddlers, either as role models or through the nutritional education of toddlers and the application of age-appropriate educational methods. In the same way, their conscious attitude towards reducing food waste through practices related to the sustainable Mediterranean diet can significantly affect the dietary choices of toddlers, in conjunction with environmental protection within the sustainability framework. By modeling mindful eating practices, educators can demonstrate how to minimize waste and appreciate the value of food [60]. Furthermore, incorporating nutritional education into the Mediterranean diet, emphasizing unprocessed, seasonal, and local products, and explaining its health and environmental benefits, can empower children to make informed food choices that support their well-being and the planet [61].

Nutrition is contained in the kindergarten curriculum in Greece, and kindergarten teachers play a significant role in promoting healthy eating in the context of a sustainable school [62]. Kindergarten teachers are responsible for applying nutrition education through various pathways, e.g., school eating routine, pedagogical meals, multidisciplinary approach education, etc. Therefore, research on nutrition literacy among preschool teachers is critical. Teachers serve as mediators in transmitting nutritional knowledge and promoting positive nutrition experiences for preschoolers. Adequate nutrition knowledge is essential to encourage parents and preschoolers to provide high-quality foods in school that meet dietary requirements [28,29].

The National Dietary Guide of Greece [63] is the official manual for nutrition recommendations at all stages of an individual’s life. It is addressed to the overall Greek population, emphasizing the Mediterranean diet’s nutritional plan and the Greek population’s nutritional requirements. Preschool teachers are responsible for children’s nutrition education and, therefore, for searching for appropriate educational material related to nutrition in early childhood. Preschool teachers, except for The National Dietary Guide of Greece [63], also have access to educational material about nutrition within the framework of teaching Skills Labs, educational clubs in school, and health education programs in kindergarten. ‘Skills Labs’ have been implemented in Greek schools of all levels and have included nutrition and nutrition literacy, targeting students of different ages, starting from preschool (Ministerial Decision F.31/94185/D1, 29 July 2021) [64]. The Institute of Educational Policy in Greece provides relevant educational materials online [62]. However, many researchers suggest that, when nutrition education is included in the school curriculum, school-based interventions seem more efficacious [65]. A systematic review and meta-analysis study suggests that researchers and government public policies should adopt theory under specific social contexts involving teachers, school staff, family, and environmental choices [66]. In the Greek curriculum in kindergarten, nutrition is mentioned within the context of interdisciplinarity across different fields of knowledge. However, it does not constitute a separate field or subject in the kindergarten curriculum.

The practice of meal planning, as well as understanding the impact of dietary choices on the environment within the framework of sustainability, is encompassed in the concept of “food literacy” rather than “nutrition literacy,” as delineated by Krause et al. [67]. Meal planning and management should be promoted using different strategies when it comes to individuals from lower socioeconomic backgrounds compared to those who are economically secure [68]. In our study, among kindergarten teachers, meal planning was positively correlated with levels of nutrition literacy, which could be explained by the fact that the concepts of nutrition literacy and food literacy are similar and may even overlap or be included in the broader concept of health literacy [67].

Studies report a disconnect between consumer awareness of food waste and actual waste reduction behaviors. While Greek consumers demonstrate a significant understanding of food waste issues, Greece still ranks highest in Europe for per capita food waste, exceeding the global average by a substantial margin [69,70,71]. This high level of waste is reflected in kindergarten teachers’ responses in the present study, as they report discarding significant amounts of food, primarily fruits, vegetables, milk, and grains. A systematic review by Aloysius et al. [72] found that consumers’ food-handling skills and knowledge at a household level are key factors determining how much leftover food is wasted. In our study, fruits and vegetables were the leading food group reported to be discarded because they spoiled before consumption or as leftovers. Research suggests that improving household food handling skills, knowledge, and better storage techniques could significantly reduce this waste [73]. Interventions targeting consumer behavior and emphasizing practical skills are crucial for translating awareness into actionable change [69,73,74].

According to the responses of kindergarten teachers, the main causes of food rejection are either spoilage before consumption or as leftovers. Theodoridis et al. [70] analyzed different types of consumers regarding food waste and revealed a significant level of food waste awareness among Greek consumers. In the present study, most teachers report discarding vegetables, milk, fruits, and grains. In the US at the consumer level, three food groups comprised 68% of the total food loss: meat (including poultry and fish), vegetables, and dairy products [75]. A systematic review conducted by Aloysius et al. [72] found that consumers’ food-handling skills and knowledge at a household level are key factors determining how much leftover food is wasted. De Laurentiis et al. [76] report that, in the EU, it is estimated that 44% and 47% of the total food waste at the household level was fruits and vegetables. Other researchers suggest that vegetable and fruit waste accounts for over 50% of European food waste [77]. In our study, fruits and vegetables were the main food group reported to be discarded, either because they spoiled before consumption or as leftovers. About 13% of fruit and vegetable waste could be prevented, as fresh produce, bakery items, and dairy are often wasted due to not being used in time [76]. Improving food storage and handling techniques can reduce the waste of perishable items, such as dairy, meat, fruits, and vegetables. Environmentally conscious teachers can educate students about proper food storage and handling. This is key to minimizing food waste and promoting responsible consumption and healthy eating habits. Teachers, through observation and experiential learning, using technology or not, could educate children about fruit and vegetable spoilage. Cooperation with local organizations or farmers’ markets can give students real-world insights into food production, preservation, healthy dietary habits, and reducing waste.

Sociocultural characteristics affect dietary choices in kindergarten, and the Mediterranean diet is the dietary pattern in line with the customs and traditions of the Greek population. Reduced food waste is linked to the appropriate use of resources and foods and their transformation and processing through traditional techniques [78]. For instance, using stale bread in cooking, making rusks that last longer, salting fish, and many others are examples of such customs. The Mediterranean diet involves skills, practices, and traditions about food, harvesting, and processing [78,79]. Maintaining sustainable dietary practices in line with the Mediterranean diet can be achieved through education for sustainable development, with preschool teachers playing a crucial role as mediators of children’s nutrition education.

5. Limitations

The study has several limitations. First, the weight and height data were self-reported. While self-reporting is a standard method for collecting anthropometric data, it is generally less accurate than measurements taken by trained professionals. Self-reported data tends to underestimate BMI, particularly at higher BMI levels. The self-report method of collecting anthropometric data is considered reliable, but with lower accuracy and a tendency for underestimation, as BMI increases might occur [80].

Considering that Greece was under COVID-19 pandemic restrictions, collecting self-reported data was the most feasible method. Another limitation is that it is a cross-sectional study, and temporal sequence and causal association between exposure and outcome cannot be established. Thus, the results should be further confirmed by a larger sample repeatedly to confirm the study trends.

6. Conclusions

In this study, Greek preschool teachers were found to be adequately nutrition literate, but their nutritional habits regarding the Mediterranean diet need improvement. In our study, high nutrition literacy scores are not related to high adherence to the Mediterranean diet. Further studies are needed to assess the factors that are barriers and inhibitors to translating nutrition knowledge into daily nutrition practice.

The school environment should reinforce healthy dietary messages, since children spend a large part of their day there. Preschool teachers are considered role models for their students, and they impart their nutritional knowledge to them. Therefore, preschool teachers should be empowered through targeted educational interventions in order to promote students’ health and healthy dietary habits towards the traditional Mediterranean diet.