Sil-Ah Kim; Su-Jin Lee; Min-Ah Kim; Ji-Eun Oh; Sohyun Park; Hyun-Joo Ryou; Ji-Yun Hwang

doi:10.5720/kjcn.2025.00220

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Research Note
Pilot evaluation of a cooking-based nutrition education program to promote vegetable intake among children in Seoul, South Korea: a single-group pre–post study: Sil-Ah Kim¹⁾, Su-Jin Lee¹⁾, Min-Ah Kim¹⁾, Ji-Eun Oh²⁾, Sohyun Park³⁾, Hyun-Joo Ryou⁴⁾, Ji-Yun Hwang^5),†; Korean Journal of Community Nutrition 2025;30(4):249-260.
DOI: https://doi.org/10.5720/kjcn.2025.00220
Published online: August 29, 2025

¹⁾Graduate Student, Department of Foodservice Management and Nutrition, Sangmyung University, Seoul, Korea

²⁾Professor, College of Science and Industry Convergence, Ewha Womans University, Seoul, Korea

³⁾Professor, Department of Food Science and Nutrition & The Korean Institute of Nutrition, Hallym University, Chuncheon, Korea

⁴⁾Director, The Ecological Eating and Culture Association, Seoul, Korea

⁵⁾Professor, Major of Foodservice Management and Nutrition, Sangmyung University, Seoul, Korea

†Corresponding author: Ji-Yun Hwang Major of Foodservice Management and Nutrition, Sangmyung University, 20 Hongjimun 2-gil, Jongno-gu, Seoul 03016, Korea Tel: +82-2-781-7607 Fax: +82-2-2287-0104 Email: jiyunhk@smu.ac.kr

• Received: July 25, 2025 • Revised: August 11, 2025 • Accepted: August 21, 2025

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Abstract
INTRODUCTION
METHODS
RESULTS
DISCUSSION
NOTES
REFERENCES

Abstract

Objectives
Food neophobia in children is often associated with limited exposure and familiarity to some foods. Cooking-based nutrition education (CBNE), which promotes acceptance through direct experience, may support the development of healthy eating habits. This study aimed to develop and implement a standardized CBNE program for school-aged children in Seoul, South Korea, and to evaluate its effectiveness by assessing changes in raw vegetable intake. Raw vegetable intake is an early indicator of the effectiveness of nutrition education on diverse topics in promoting healthy eating habits.
Methods
A single-group pre–post study was conducted with 37 children aged 6–11 years who participated in a 2-day CBNE program in October 2023. The participants completed pre- and post-education questionnaires and raw vegetable intake assessments. Four low-preference vegetables (bell pepper, carrot, cucumber, and tomato) were selected and served raw (25 g each) before and after the program. Intake changes were analyzed using paired t-tests, and Pearson’s correlation and hierarchical regression analyses were performed to identify predictors.
Results
Total raw vegetable intake significantly increased post-education (P = 0.008), particularly for carrots (P = 0.023). By subgroup, raw vegetable intake significantly increased in girls, upper-grade students, and those who consumed four or more vegetable side dishes per meal. Hierarchical regression analysis revealed that while vegetable preference was initially significant, vegetable-related experiences (β = 0.395, P = 0.026) and diversity of vegetable side dishes per meal (β = 0.403, P = 0.032) were stronger predictors in the final model (adj R² = 0.333).
Conclusion
The CBNE program may enhance vegetable intake in children. Although preference remained the strongest individual factor, vegetable experience and the diversity of vegetable side dishes per meal had a greater combined effect. These findings underscore the importance of repeated and diverse exposure, not only by supporting previous studies that link such exposure to increased intake but also by suggesting that environmental support may be essential for sustaining healthy eating habits.
Keywords: child; vegetables; diet, healthy; health education; pilot projects

INTRODUCTION

Childhood is a critical period of growth and development, and nutrition and lifestyle during this period facilitate the transition to adolescence and form the foundation for dietary preferences and eating habits in adulthood [1, 2]. Diversity in food choices is essential to achieve balanced nutrient intake; however, children may show the tendency to avoid vegetable consumption while preferring meat, instant foods, and processed foods [3, 4]. Other nutritional problems in children include a preference for energy-dense snacks, irregular meals, picky eating, and increasing obesity due to the excessive consumption of instant and high-energy foods [5]. Processed foods contain high levels of potentially harmful nutritional components, such as sugars, sodium, saturated fats, trans fats, and cholesterol, which increase the prevalence of chronic adult diseases [6]. The proportion of sugar intake through processed foods in children has been reported to be approximately 9.7%, nearly reaching the World Health Organization’s recommended limit of 10%; moreover, more than half of the children (79.6% boys and 75.5% girls) were reported to consume fast food at least once per week [7]. The rates of overweight and obesity are the highest among boys aged 10–11 years and girls aged 11–18 years, emphasizing the importance of consuming vegetables, which are low in energy but rich in nutrients [8]. However, vegetables are representative foods that children avoid, with only 13.5% of this age group consuming 500 g or more of fruits and vegetables daily; moreover, the average daily vegetable intake was only 139.4 g, which is significantly lower than the recommended dietary pattern [9, 10]. Vegetable avoidance mainly occurs in children with insufficient nutritional knowledge and poor eating behaviors, resulting in inadequate intake of micronutrients such as vitamins and minerals [4]. Unhealthy eating habits can lead to malnutrition and affect children’s physical and mental growth, impeding their psychosomatic development and learning abilities [11, 12].

Children tend to avoid unfamiliar foods that they have not tried or frequently encountered, often citing poor taste as the reason. Food and taste preferences are learned through experience and the surrounding environment, which influence food choices and consumption frequency [13]. Therefore, reducing aversion to unfamiliar foods through experiential nutrition education that allows exposure to various foods is essential. Experiential nutrition education includes sensory education and cooking practice and is defined as a practice-based educational method that enables participants to assign new meanings to foods through educational activities based on taste science and the five senses [14, 15]. In comparison with one-way education, this approach has been reported to yield notable effects on forming proper eating habits, including higher interest and participation among children, improved self-efficacy, and increased acceptance of avoided foods [15, 16].

Children show differences in cognitive development, sensory acceptance, and self-regulation abilities according to age, necessitating standardized experiential nutrition education programs that account for developmental characteristics. Standardized education refers to structured education that ensures consistency and reliability based on certain standards and procedures [17]. Accordingly, children’s dietary and nutritional education content and user guides have been developed, providing a systematic framework for designing age-appropriate education with a consistent scope and sequence [18]. However, the demonstration of educational effects using these materials remains insufficient. Therefore, this study developed a cooking-based nutrition education program and related content based on previously developed standardized educational materials, and pilot-tested it with school-aged children residing in Seoul, South Korea. Educational effects were evaluated by focusing on the degree of formation of healthy eating habits in children, using vegetable intake levels as an indicator that can serve as an early measure of learning effects related to healthy food preferences and consumption methods [19].

A representative example of using vegetable intake as an evaluation indicator for cooking-based nutrition education program effects is the Modifying Eating and Lifestyles at School (MEALS) study in the United States [20]. This study assigned professional chefs to elementary schools to develop recipes using whole grains, fresh and frozen produce, unsaturated fats, and seasonings without added salt or sugar; apply these to school meals; and have students repeatedly experience them for seven months. As a result, more students chose vegetables after the intervention, and vegetable intake increased approximately twofold [20]. The MEALS study aimed to evaluate changes in raw vegetable intake following education. However, for a more valid interpretation of educational effects as well as the development of practical strategies to promote children’s vegetable intake, the major factors influencing vegetable intake require consideration. Therefore, this study aimed to explore the major factors affecting vegetable intake, identify the interactive context between educational effects and these factors, and ultimately contribute to the establishment of evidence-based strategies to promote vegetable intake in children.

METHODS

Ethics statement

Written informed consent was obtained from all participants and/or the guardians for the survey. The survey procedures and protocols were approved by the Institutional Review Board at Hallym University (HIRB-2023-018).

1. Study design

This single-group pre–post study involved children who participated in the pilot application of a cooking-based nutrition education program. The program is described according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guidelines (https://www.strobe-statement.org/).

2. Study participants and period

This study was conducted in Seoul, South Korea. The study participants were school-aged children (age, 6–11 years) who participated in a pilot application of a cooking-based nutrition education program in October 2023. Participants were recruited between August 24 and September 29, with promotions conducted through social networking service platforms and cooperation from the Seoul Metropolitan Government Food Life Support Center. Pre- and post-education surveys and raw vegetable intake assessments were conducted with 37 school-aged children who expressed willingness to participate in the study and received consent from their legal guardians.

3. Planning and implementation of nutrition education

To develop educational programs and content appropriate for the developmental characteristics of the participants, the school-aged children were divided into three groups on the basis of their elementary school curriculum: grades 1–2, grades 3–4, and grades 5–6. The education program and content included information regarding nutrition and hygiene management and prevention of overweight and obesity; the content was prepared by referencing previously developed children’s dietary and nutrition education content and user guides for elementary students [18]. On the basis of these references, low-sodium and low-sugar cooking practice recipes, presentation materials (PPT), and activity sheets were developed considering taste science and the five senses, enabling participants to have food experiences that helped them assign new meanings to foods.

To address major nutritional problems in children, including avoidance of fruits and vegetables and excessive consumption of instant and processed foods, the cooking-based nutrition education program was structured with themes of “raw and pickled vegetables” and “salt and salty taste” for grades 1–2, “processed foods and sweets” for grades 3–4, “sustainable eating” for grades 5–6, and “choosing healthy ingredients” and “whole grain experience” for households with school-aged children. Education was conducted in three stages, totaling 80 minutes: theory classes including sensory activities (30 minutes), cooking activities (40 minutes), and wrap-up activities (10 minutes). During the theory classes with sensory activities, nutritional knowledge was delivered using PPT and activity sheets. During the cooking activities, the participants performed hands-on cooking practices under instructor guidance using age-appropriate cooking tools. Cooking practices were conducted according to educational themes: “making salads and pickled vegetables” for grades 1–2, “making low-sugar ice cream” for grades 3–4, “making environmentally friendly rice balls” for grades 5–6, and “making pasta with seasonal vegetables” and “making whole grain granola” for households with school-aged children. During the wrap-up activities, the learning content was summarized, commitment-making and true/false quizzes were conducted, and seasonal low-sodium and low-sugar recipes were provided to help with real-life practice (Table 1).

4. Evaluation of the effects of nutrition education

The effects of nutrition education were evaluated through pre- and post-education surveys and raw vegetable intake assessments. Pre- and post-education surveys were conducted by distributing questionnaires to school-aged children before and after the cooking-based nutrition education. These questionnaires were constructed by modifying and supplementing previously validated items from early childhood healthy eating practice questionnaires, nutrition quotient, and Yook and Hwang [21] research to fit the participant population of the present study [21-25]. Pre-education questionnaires included questions related to the participants’ general characteristics, vegetable awareness, experience, and preference levels, while post-education questionnaires included questions assessing healthy eating efficacy and the diversity of vegetable side dishes consumed per meal (based on the number of types). The general characteristics included name, sex, date of birth, and age. Vegetable awareness, experience, and preference levels were measured using a 5-point Likert scale (1: strongly disagree, 2: disagree, 3: neutral, 4: agree, and 5: strongly agree). Healthy eating efficacy was measured using five items on a 5-point Likert scale (1: strongly disagree, 2: disagree, 3: neutral, 4: agree, and 5: strongly agree), and the diversity of vegetable side dishes consumed per meal (based on the number of types) was evaluated in five categories (1: rarely eat, 2: one type, 3: two types, 4: three types, and 5: four or more types).

The raw vegetable intake assessment evaluated behavioral changes that are difficult to measure through surveys [26, 27], and examined intake changes by providing raw vegetables to participants before and after cooking-based nutrition education. Four types of vegetables that had shown low preference among school-aged children in previous studies [8, 28-31] were provided: bell pepper, carrot, cucumber, and tomato. Considering the vegetable consumption frequency for school-aged children presented in the recommended dietary pattern of the 2020 Korean Dietary Reference Intakes, the median individual serving size was set at 70 g, with 25 g provided before and after nutritional education [10]. The amounts remaining after vegetable provision were weighed and recorded, and intake was calculated by subtracting the remaining amount from the amount provided during data processing.

5. Statistical analysis

All data were analyzed using IBM SPSS Statistics (version 27.0; IBM Corp.), and the significance level was set at P < 0.05. Frequencies and percentages were calculated for sex and grade among the participants’ general characteristics, and means and standard deviations were calculated for age. Age was calculated as chronological age based on the data collection time, and grades for those participating in family programs with school-aged children were classified as grades 1–2 (age, 6–7 years), grades 3–4 (age, 8–9 years), and grades 5–6 (age, 10–11 years) on the basis of the age at participation in cooking-based nutrition education program. Mean and standard deviation values were calculated for pre-education vegetable awareness, experience, and preference, and post-education healthy eating efficacy. Frequencies and percentages by response category were calculated for the diversity of vegetable side dishes per meal (based on number of types), and mean and standard deviation values were calculated by coding “rarely eat” as 0. Since some groups had small sample sizes, the diversity of vegetable side dishes consumed per meal (based on the number of types) was analyzed by combining adjacent groups for variance estimation and statistical power safety as follows: groups consuming two or fewer types (n = 13), three types (n = 12), and four or more types (n = 12).

Mean differences in raw vegetable intake before and after education were analyzed using paired t-tests, and additional differences between groups were examined in relation to the categorical variables, including sex, grade, and diversity of vegetable side dishes consumed per meal (based on the number of types). To identify the factors influencing the participants’ raw vegetable intake, linear relationships between major variables were preliminarily explored using Pearson’s correlation analysis, and hierarchical regression analysis was performed after examining multicollinearity.

RESULTS

1. General characteristics of the participants and pre- and post-education survey results

The general characteristics of the participants and the pre- and post-education survey results are presented in Table 2. The participants included 20 girls (54.1%) and 17 boys (45.9%), and their mean age was 9.2 ± 1.6 years. Eleven students (29.7%) in grades 1–2, 16 (43.2%) in grades 3–4, and 10 (27.0%) in grades 5–6 participated in the study, with grades 3–4 showing the highest participation. Vegetable awareness, experience, and preference scores were 4.8 ± 0.3, 4.7 ± 0.5, and 3.8 ± 1.0, respectively. Participants’ healthy eating efficacy was 4.0 ± 0.7 points, and the diversity of vegetable side dishes consumed per meal (based on number of types) was 2.8 ± 1.1, with two or fewer types being the most common (13 participants; 35.1%), followed by three types and four or more types (12 participants each; 32.4%).

2. Raw vegetable intake before and after nutrition education

Changes in the participants’ raw vegetable intake before and after education are shown in Table 3. Among the four types of raw vegetables provided, bell pepper intake was 6.8 ± 7.6 g before education and 9.3 ± 11.1 g after education, showing a non-significant but increasing trend after education (P = 0.166). Carrot intake significantly increased from 4.9 ± 6.8 g before education to 8.8 ± 10.3 g after education (P = 0.023). Cucumber intake was 7.7 ± 7.0 g before education and 10.3 ± 10.5 g after education, showing a non-significant but increasing trend after education (P = 0.077). Tomato intake was the highest among the four raw vegetables, showing a non-significant increase from 15.0 ± 11.0 g before education to 18.5 ± 10.5 g after education (P = 0.059). Total raw vegetable intake showed a significant increase from 34.3 ± 19.6 g before education to 46.9 ± 31.3 g after education (P = 0.008).

3. Raw vegetable intake before and after education in relation to sex, grade, and diversity of vegetable side dishes per meal (based on number of types)

Table 4 summarizes the group-specific results of raw vegetable intake before and after education, stratified by sex, grade, and the diversity of vegetable side dishes per meal. Boys showed increasing trends in the intake of all four raw vegetables after education; however, these differences were not statistically significant. Girls showed significant increases in carrot (P = 0.029), tomato (P = 0.015), and total raw vegetable (P = 0.006) intake after education, whereas bell pepper and cucumber intake showed increasing trends without significant differences after education. When assessed by grade, students in higher grades showed greater increments in raw vegetable intake after education. In terms of individual vegetables, grades 1–2 showed non-significant upward trends in bell pepper, carrot, cucumber, and total raw vegetable intake after education, while tomato intake showed a slight, non-significant decrease. Grades 3–4 showed non-significant but increasing trends in carrot, cucumber, tomato, and total raw vegetable intake after education, while bell pepper intake decreased non-significantly. Grades 5–6 showed significant increments in bell pepper (P = 0.049), tomato (P = 0.012), and total raw vegetable intake (P = 0.030) after education, whereas carrot and cucumber intake showed non-significant but increasing trends. Regarding the diversity of vegetable side dishes consumed per meal (based on number of types), only the group that consumed 4 or more types, showed significant increases in bell pepper (P = 0.017), carrot (P = 0.034), cucumber (P = 0.014), tomato (P = 0.041), and total raw vegetable intake (P = 0.002) after education.

4. Correlations between raw vegetable intake and major variables

The correlations between total raw vegetable intake and major variables are shown in Table 5. Total raw vegetable intake showed a significant positive correlation with participant age (r = 0.379, P < 0.05), vegetable experience (r = 0.405, P < 0.05), vegetable preference (r = 0.453, P < 0.01), and diversity of vegetable side dishes consumed per meal (based on the number of types) (r = 0.408, P < 0.05). In the assessment of correlations between the major variables, vegetable preference showed a significant positive correlation with age (r = 0.353, P < 0.05). The diversity of vegetable side dishes consumed per meal (based on the number of types) showed a significantly positive correlation with vegetable preference (r = 0.447, P < 0.01) and healthy eating efficacy (r = 0.471, P < 0.01). Experience with vegetables was significantly and positively correlated with age (r = 0.326, P < 0.05) and vegetable awareness (r = 0.495, P < 0.01).

5. Stepwise explanatory power of major predictors for raw vegetable intake

The effects of vegetable awareness, experience, preference, healthy eating efficacy, and diversity of vegetable side dishes consumed per meal (based on the number of types) on total raw vegetable intake were examined stepwise using hierarchical regression analysis (Table 6). The model showed a Durbin–Watson value of 1.754, approximating 2, confirming the independence of residuals for the dependent variable, and variance inflation factor values below 10, indicating no multicollinearity problems among the independent variables. In step 1 for the development of the regression model, the model was adjusted by including the control variables sex and age. Model 1 did not show statistical significance (F = 2.857, P = 0.071), but age appeared to be a significant predictor affecting raw vegetable intake (β = 0.377, P = 0.024). Model 1’s explanatory power was 14.4%, and its adjusted explanatory power was 9.4%, indicating low explanatory power for raw vegetable intake (R² = 0.144, adj R² = 0.094). In step 2, vegetable awareness was added, but model significance was not achieved (△F = 0.247, P = 0.623). Among individual variables, age maintained its significance level (β = 0.372, P = 0.028), while vegetable awareness was not statistically significant (β = 0.081, P = 0.623). Model 2’s explanatory power was 15.0%, which was higher than that of Model 1, but the adjusted explanatory power of Model 2 (7.3%) was lower than that of Model 1 (9.4%; R² = 0.150, adj R² = 0.073), indicating that vegetable awareness did not provide independent explanatory power for raw vegetable intake.

In step 3, vegetable experience was added, but the overall model was not statistically significant (△F = 3.791, P = 0.060). In particular, the significance of age, which was maintained in Models 1 and 2, was not achieved (β = 0.262, P = 0.122), and all variables lacked significance. Model 3 showed greater explanatory power (24.0% vs. 15.0%) and greater adjusted explanatory power (14.5% vs. 7.3%) than Model 2, but the improvement was not substantial (R² = 0.240, adj R² = 0.145). In step 4, vegetable preference was added to achieve model significance (F = 5.329, P = 0.028). Model 4 showed greater explanatory power (35.2% vs. 24.0%) and adjusted explanatory power (24.7% vs. 14.5%) than Model 3, indicating improved explanatory power (R² = 0.352, adj R² = 0.247). Only vegetable preference was a significant predictor affecting raw vegetable intake (β = 0.376, P = 0.028).

In step 5, healthy eating efficacy was added, and model significance disappeared (△F = 0.809, P = 0.376). However, vegetable experience and vegetable preference appeared as significant predictors (β = 0.374, P = 0.045; β = 0.419, P = 0.020). Model 5’s explanatory power was 36.9%, which was greater than that of Model 4, but the adjusted explanatory power was 24.2%, which was lower than that of Model 4 (R² = 0.369, adj R² = 0.242). This finding indicated that healthy eating efficacy was not suitable for explaining raw vegetable intake (β = –0.138, P = 0.376). In step 6, diversity of vegetable side dishes consumed per meal (based on number of types) was added, and the overall model showed statistical significance (△F = 5.060, P = 0.032). With the addition of variables, vegetable preference’s significance, which was maintained in Models 4 and 5, was not achieved, and vegetable experience and diversity of vegetable side dishes consumed per meal (number of types) were confirmed as significant predictors (β = 0.395, P = 0.026; β = 0.403, P = 0.032). Model 6’s explanatory power was 46.2%, which was higher than that of Model 5, and its adjusted explanatory power was 33.3%, also higher than that of Model 5 (R² = 0.462, adj R² = 0.333).

DISCUSSION

This single-group pre–post study was conducted in Seoul, South Korea, with 37 school-aged children (age, 6–11 years) who participated in a pilot application of a cooking-based nutrition education program. This study aimed to evaluate the effects of nutrition education and explore the factors influencing vegetable intake through pre- and post-education surveys and raw vegetable intake assessments. The findings showed significant increments in carrot and total raw vegetable intake after education, which are similar to the results of nutrition education addressing overall healthy eating in young children, where vegetable intake increased after education [26, 27]. In the US nutrition education program “Color Me Healthy,” which included club activities where young children could directly taste fruits and vegetables and participate in imaginary journeys, including role-playing about physical activity and eating nutritious foods, vegetable intake continued to increase at 1 week and 3 months post-baseline in exposed young children [26]. Domestically, when eight sessions of nutritional education based on fruits, vegetables, and national common dietary guidelines were provided to young children, vegetable intake significantly increased [27]. However, this study differed in that it measured changes in both total and individual vegetable intake; in particular, significant increments were noted in the intake of carrots, which had the lowest intake before education, highlighting the effects of this approach in reducing vegetable avoidance.

The increments in raw vegetable intake were particularly evident in girls, children in the upper grades, and the group consuming four or more types of vegetable side dishes per meal, consistent with the results reported in previous studies. Girls have previously shown higher preference scores for 10 types of vegetables than boys [29], and girls consume more vegetables per serving than boys [32]. Children in upper grades have been reported to eat more balanced diets and show higher preferences for seasoned vegetables, salads, and kimchi than those in lower grades [33], which is closely related to the phenomenon of increased vegetable consumption frequency with increasing age [16, 34]. The diversity of vegetable side dishes is related to home availability, with children who frequently encounter home-cooked vegetables eating more vegetables [35-37]. These results show that boys, children in lower grades, and children with low diversity in vegetable side dishes consumed per meal may be relatively vulnerable to low vegetable intake, emphasizing the need to develop and apply customized nutrition education for these groups.

Raw vegetable intake was related to age, vegetable experience, vegetable preference, and the diversity of vegetable side dishes, with the major factors affecting increased vegetable intake and the diversity of vegetable side dishes. Vegetable experience as an individual factor could not explain increased raw vegetable intake, but it showed high explanatory power when combined with diversity of vegetable side dishes. As an individual factor, vegetable preference best explained increased intake of raw vegetables. This finding supports the importance of direct vegetable experience and diverse exposures to intake behavior, indicating the importance of cooking-based nutrition education. Previous studies have also confirmed that food neophobia decreased in children with repeated exposure to various vegetables, and vegetable intake tended to increase as exposure duration increased [31, 38]. For vegetable preference, although actual tasting experiences are generally considered necessary for the translation of visual preferences to intake behavior, one study reported that vegetable intake significantly increased in young children who had six months of visual exposure to vegetables. These findings suggest that further research is needed to clarify the relationship between vegetable preferences and actual vegetable intake [39, 40].

In summary, when sufficient vegetable exposure at home is supported, implementing vegetable experience activities, that is, cooking-based nutrition education, is more effective in increasing raw vegetable intake and can have positive effects on forming correct perceptions about vegetable intake and improving dietary efficacy in school-aged children. Vegetable consumption is also an important element of sustainable eating for both human health and the environment. The Eat-Lancet Commission’s Global Planetary Health Diet emphasizes that whole grains, fruits, nuts, legumes, and vegetables should account for a large proportion of total food intake [41]. Therefore, education focusing on the importance of vegetable intake for sustainable eating is needed for school-aged children; however, in Korea, related research is still limited to programs such as gardening activities for young children and food ecological transition education [42, 43]. Greater emphasis on sustainable eating education linked to vegetable intake can help school-aged children develop healthy and environmentally friendly eating habits.

Limitations

This pilot study used purposive sampling methods with only 37 school-aged children (ages 6–11 years) who participated in the pilot application of a cooking-based nutrition education program as research participants. Nutrition education was conducted in a single group, and significant increments were observed in carrot and total raw vegetable intake after education. However, some vegetables did not show significant increments in intake and showed only increasing trends. The lack of a control group and the use of only a single session of nutrition education limited the ability to clearly identify the causal relationships between nutrition education and raw vegetable intake. Future studies with more education sessions would be more effective to form correct perceptions of vegetable intake and improve dietary efficacy.

Conclusion

This study divided school-aged children in Seoul, South Korea into three groups, grades 1–2, 3–4, and 5–6, which reflect the rapid physical changes during growth periods rather than the conventional two groups of lower grades (1–3) and upper grades (4–6). This is the first study to present the effects of a cooking-based nutrition education program using previously developed standardized educational materials. The healthy eating habit formation effects of nutrition education, which are difficult to measure through surveys, were evaluated on the basis of raw vegetable intake before and after education, which resulted in significant increments in carrot and total raw vegetable intake after education. These increments in raw vegetable intake were greatly influenced by the vegetable experience and the diversity of vegetable side dishes consumed per meal. This finding suggests that vegetable exposure at home is important for increasing raw vegetable intake and vegetable experience activities. Therefore, if cooking-based nutritional education for school-aged children and their families continues through community connections, it will be effective in promoting healthy eating habits.

NOTES

CONFLICT OF INTEREST

There are no financial or other issues that might lead to conflict of interest.

FUNDING

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (RS-2023-00280503).

DATA AVAILABILITY

Research data is available upon request to the corresponding author.

Table 1.

Cooking-based nutrition education program for school-aged children

Grade	Program title	Theory-based nutrition education with sensory activities (30 min)	Cooking (40 min)	Wrap-up (10 min)
Lower (1st–2nd)	Raw & pickled vegetables	- Sensory characteristics of vegetables, including taste, aroma, and texture	Making a salad and pickled vegetables	Making commitment: putting today’s learning into practice
		- Effects of cutting style on vegetable texture		True or false quiz
		- Understanding the characteristics and benefits of seasonal vegetables		Offering seasonal low-sodium and low-sugar recipes
		- Proper techniques for vegetable storage and handling
	Salt & salty taste	- The role of salt in food and human body
		- Understanding ingredients and dishes with salty flavor
		- Identifying foods and ingredients with a salty taste
		- Experiencing salty taste through sensory activities
Middle (3rd–4th)	Processed foods & sweets	- Choosing healthy snacks: reading sugar and sodium information	Making low-sugar ice cream
		- Experiencing differences in sweetness depending on temperature
		- Understanding the meaning of the consumption date
		- Recognizing food poisoning situations and prevention methods
Upper (5th–6th)	Sustainable eating	- Understanding the food system: from farm to table	Making environmentally friendly rice balls
		- Learning about food mileage and low-carbon eating practices
		- Reading nutrition labels and food additives
		- Proper storage and handling of processed foods
Households with school-aged children	Choosing healthy ingredients	- Identifying spoiled or unsafe ingredients	Preparing pasta with seasonal vegetables
		- Understanding processed foods and food additives
		- Reading nutrition labels and choosing healthy snacks
	Whole grain experience	- Understanding seasonal grains	Making whole grain granola
		- Observing and identifying different types of grains
		- Distinguishing between non-glutinous and glutinous rice
		- Proper storage of grains
		- Changes in the appearance of grains during cooking
		- Learning about whole grain snacks

Table 2.

General characteristics of the subjects and results of pre- and post- education questionnaires (n = 37)

Variables	School-aged children
General characteristics
Sex
Boys	17 (45.9)
Girls	20 (54.1)
Age (year)	9.2 ± 1.6
Grades
Lower (1st–2nd)	11 (29.7)
Middle (3rd–4th)	16 (43.2)
Upper (5th–6th)	10 (27.0)
Pre-education questionnaire
Vegetables
Awareness	4.8 ± 0.3
Experience	4.7 ± 0.5
Preference	3.8 ± 1.0
Post-education questionnaire
Healthy eating efficacy	4.0 ± 0.7
Diversity of vegetable side dishes per meal¹⁾
2 fewer types	13 (35.1)
3 types	12 (32.4)
4 or more types	12 (32.4)
Total	2.8 ± 1.1

n (%) or mean ± SD.

¹⁾Number of types, including kimchi.

Table 3.

Changes in raw vegetable intake before and after education (n = 37)

Variables	Raw vegetables intake		Range	t	P-value¹⁾
Variables	Pre-test	Post-test	Range	t	P-value¹⁾
Bell pepper (g)	6.8 ± 7.6	9.3 ± 11.1	0–25	–1.42	0.166
Carrot (g)	4.9 ± 6.8	8.8 ± 10.3	0–25	–2.37	0.023
Cucumber (g)	7.7 ± 7.0	10.3 ± 10.5	0–25	–1.82	0.077
Tomato (g)	15.0 ± 11.0	18.5 ± 10.5	0–25	–1.95	0.059
Total (g)	34.3 ± 19.6	46.9 ± 31.3	0–100	–2.80	0.008

mean ± SD.

¹⁾The significance level for statistical analysis was P < 0.05. Comparisons were performed using the paired t-test.

Table 4.

Changes in raw vegetable intake before and after education according to sex, grades and diversity of vegetable side dishes per meal (based on the number of types)

Variables	Category	Vegetable intake
		Bell pepper		P-value¹⁾	Carrot		P-value¹⁾	Cucumber		P-value¹⁾	Tomato		P-value¹⁾	Total		P-value¹⁾
		Pre-test	Post-test	P-value¹⁾	Pre-test	Post-test	P-value¹⁾	Pre-test	Post-test	P-value¹⁾	Pre-test	Post-test	P-value¹⁾	Pre-test	Post-test	P-value¹⁾
Sex	Boys (n = 17)	8.3 ± 8.2	11.2 ± 12.0	0.323	6.4 ± 8.4	8.4 ± 11.1	0.393	9.1 ± 8.3	11.1 ± 11.4	0.446	11.1 ± 11.9	13. 0 ± 11.9	0.582	34.9 ± 25.8	43.8 ± 40.5	0.278
Sex	Girls (n = 20)	5.6 ± 7.2	7.7 ± 10.4	0.352	3.6 ± 4.9	9.1 ± 9.8	0.029	6.4 ± 5.6	9.6 ± 9.9	0.066	18.3 ± 9.1	23.3 ± 6.2	0.015	33.8 ± 12.9	49.6 ± 21.5	0.006
Grades	Lower (n = 11)	6.6 ± 9.6	6.6 ± 10.6	0.965	2.9 ± 7.4	7.3 ± 10	0.094	6.6 ± 9.1	8.3 ± 11	0.462	13.6 ± 11.9	12.3 ± 12.3	0.619	29.7 ± 28.8	34.5 ± 34.6	0.496
	Middle (n = 16)	7.3 ± 7.1	6.7 ± 9.7	0.801	3.3 ± 4.5	7.7 ± 8.7	0.062	5.4 ± 5.5	7.7 ± 8.4	0.258	17.5 ± 10.8	19.6 ± 10.3	0.429	33.4 ± 12.5	41.7 ± 25.7	0.171
	Upper (n = 10)	6.5 ± 6.8	16.5 ± 11.7	0.049	9.5 ± 7.4	12.1 ± 13	0.578	12.4 ± 4.4	16.7 ± 11.1	0.296	12.4 ± 10.4	23.7 ± 3.8	0.012	40.8 ± 16.7	69.0 ± 26.7	0.030
Diversity of vegetable side dishes per meal²⁾	2 or fewer types (n = 13)	6.6 ± 8.1	5.3 ± 9.1	0.579	1.6 ± 2.6	3.4 ± 5.2	0.282	4.2 ± 6.3	5.2 ± 7.5	0.656	15.5 ± 11.0	14.5 ± 12.5	0.801	27.9 ± 16.1	28.5 ± 26.2	0.929
	3 types (n = 12)	8.8 ± 7.2	8.8 ± 12.1	0.978	7.8 ± 7.8	8.9 ± 11.2	0.674	9.3 ± 8.1	9.3 ± 10.5	0.975	16.8 ± 11.3	21.8 ± 7.8	0.074	42.6 ± 26.8	48.8 ± 31.3	0.406
	4 or more types (n = 12)	5.2 ± 7.8	14.2 ± 11.1	0.017	5.5 ± 7.8	14.4 ± 11.0	0.034	9.7 ± 5.6	16.8 ± 10.5	0.014	12.7 ± 11.1	19.6 ± 9.8	0.041	33.0 ± 11.2	65.0 ± 26.8	0.002

mean ± SD.

¹⁾The significance level for statistical analysis was P < 0.05. Comparisons were performed using the paired t-test.

²⁾Number of types, including kimchi.

Table 5.

Correlation analysis between total raw vegetable intake and major variables (n = 37)

Variables	Age	Awareness	Experience	Preference	Healthy eating efficacy	Diversity of vegetable side dishes per meal¹⁾	Total raw vegetable intake
Age	1
Awareness	0.047	1
Experience	0.326^*	0.495^**	1
Preference	0.353^*	0.297	0.257	1
Healthy eating efficacy	0.121	0.078	0.133	0.315	1
Diversity of vegetable side dishes per meal¹⁾	0.169	–0.036	0.038	0.447^**	0.471^**	1
Total raw vegetable intake	0.379^*	0.094	0.405^*	0.453^**	0.040	0.408^*	1

¹⁾Number of types, including kimchi.

^*P < 0.05,

^**P < 0.01.

Table 6.

Hierarchical regression analysis of major predictors on total raw vegetable intake (n = 37)

Independent variables	Model 1				Model 2				Model 3				Model 4				Model 5				Model 6
Independent variables	B	SE	t	β	B	SE	t	β	B	SE	t	β	B	SE	t	β	B	SE	t	β	B	SE	t	β
Sex¹⁾	0.769	7.015	0.110	0.017	1.347	7.189	0.187	0.031	0.553	6.915	0.080	0.013	2.246	6.531	0.344	0.051	1.856	6.566	0.283	0.042	–3.055	6.537	–0.467	–0.069
Age	5.419	2.290	2.367	0.377^*	5.346	2.320	2.304	0.372^*	3.766	2.371	1.589	0.262	1.905	2.367	0.805	0.133	1.889	2.374	0.796	0.132	2.048	2.229	0.919	0.143
Awareness					5.409	10.886	0.497	0.081	–6.650	12.150	–0.547	–0.099	–13.072	11.738	–1.114	–0.195	–13.695	11.795	–1.161	–0.205	–10.507	11.160	–0.941	–0.157
Experience									17.112	8.788	1.947	0.369	16.784	8.249	2.035	0.362	17.360	8.300	2.092	0.374^*	18.339	7.801	2.351	0.395^*
Preference													8.734	3.783	2.309	0.376^*	9.719	3.950	2.460	0.419^*	5.835	4.089	1.427	0.251
Healthy eating efficacy																	–4.557	5.068	–0.899	–0.138	–9.675	5.272	–1.835	–0.293
Diversity of vegetable side dishes per meal²⁾																					8.203	3.647	2.249	0.403^*
(Constant)	–10.503	23.039	–0.456	-	–36.674	57.595	–0.637	-	–42.817	55.393	–0.773	-	–28.859	52.338	–0.551	-	–13.374	55.253	–0.242	-	–15.376	51.863	–0.296	-
R²	0.144				0.150				0.240				0.352				0.369				0.462
△R²	0.094				0.073				0.145				0.247				0.242				0.333
F	2.857				1.945				2.530				3.363^*				2.920^*				3.565^**
△F	2.857				0.247				3.791				5.329^*				0.809				5.060^*

¹⁾Sex coded as boys = 1, girls = 2.

²⁾Number of types, including kimchi.

^*P < 0.05,

^**P < 0.01.

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Pilot evaluation of a cooking-based nutrition education program to promote vegetable intake among children in Seoul, South Korea: a single-group pre–post study

Korean J Community Nutr. 2025;30(4):249-260. Published online August 29, 2025

DOI: https://doi.org/10.5720/kjcn.2025.00220

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Pilot evaluation of a cooking-based nutrition education program to promote vegetable intake among children in Seoul, South Korea: a single-group pre–post study

Grade	Program title	Theory-based nutrition education with sensory activities (30 min)	Cooking (40 min)	Wrap-up (10 min)
Lower (1st–2nd)	Raw & pickled vegetables	- Sensory characteristics of vegetables, including taste, aroma, and texture	Making a salad and pickled vegetables	Making commitment: putting today’s learning into practice
		- Effects of cutting style on vegetable texture		True or false quiz
		- Understanding the characteristics and benefits of seasonal vegetables		Offering seasonal low-sodium and low-sugar recipes
		- Proper techniques for vegetable storage and handling
	Salt & salty taste	- The role of salt in food and human body
		- Understanding ingredients and dishes with salty flavor
		- Identifying foods and ingredients with a salty taste
		- Experiencing salty taste through sensory activities
Middle (3rd–4th)	Processed foods & sweets	- Choosing healthy snacks: reading sugar and sodium information	Making low-sugar ice cream
		- Experiencing differences in sweetness depending on temperature
		- Understanding the meaning of the consumption date
		- Recognizing food poisoning situations and prevention methods
Upper (5th–6th)	Sustainable eating	- Understanding the food system: from farm to table	Making environmentally friendly rice balls
		- Learning about food mileage and low-carbon eating practices
		- Reading nutrition labels and food additives
		- Proper storage and handling of processed foods
Households with school-aged children	Choosing healthy ingredients	- Identifying spoiled or unsafe ingredients	Preparing pasta with seasonal vegetables
		- Understanding processed foods and food additives
		- Reading nutrition labels and choosing healthy snacks
	Whole grain experience	- Understanding seasonal grains	Making whole grain granola
		- Observing and identifying different types of grains
		- Distinguishing between non-glutinous and glutinous rice
		- Proper storage of grains
		- Changes in the appearance of grains during cooking
		- Learning about whole grain snacks

Variables	School-aged children
General characteristics
Sex
Boys	17 (45.9)
Girls	20 (54.1)
Age (year)	9.2 ± 1.6
Grades
Lower (1st–2nd)	11 (29.7)
Middle (3rd–4th)	16 (43.2)
Upper (5th–6th)	10 (27.0)
Pre-education questionnaire
Vegetables
Awareness	4.8 ± 0.3
Experience	4.7 ± 0.5
Preference	3.8 ± 1.0
Post-education questionnaire
Healthy eating efficacy	4.0 ± 0.7
Diversity of vegetable side dishes per meal¹⁾
2 fewer types	13 (35.1)
3 types	12 (32.4)
4 or more types	12 (32.4)
Total	2.8 ± 1.1

Variables	Raw vegetables intake		Range	t	P-value¹⁾
Variables	Pre-test	Post-test	Range	t	P-value¹⁾
Bell pepper (g)	6.8 ± 7.6	9.3 ± 11.1	0–25	–1.42	0.166
Carrot (g)	4.9 ± 6.8	8.8 ± 10.3	0–25	–2.37	0.023
Cucumber (g)	7.7 ± 7.0	10.3 ± 10.5	0–25	–1.82	0.077
Tomato (g)	15.0 ± 11.0	18.5 ± 10.5	0–25	–1.95	0.059
Total (g)	34.3 ± 19.6	46.9 ± 31.3	0–100	–2.80	0.008

Variables	Category	Vegetable intake
		Bell pepper		P-value¹⁾	Carrot		P-value¹⁾	Cucumber		P-value¹⁾	Tomato		P-value¹⁾	Total		P-value¹⁾
		Pre-test	Post-test	P-value¹⁾	Pre-test	Post-test	P-value¹⁾	Pre-test	Post-test	P-value¹⁾	Pre-test	Post-test	P-value¹⁾	Pre-test	Post-test	P-value¹⁾
Sex	Boys (n = 17)	8.3 ± 8.2	11.2 ± 12.0	0.323	6.4 ± 8.4	8.4 ± 11.1	0.393	9.1 ± 8.3	11.1 ± 11.4	0.446	11.1 ± 11.9	13. 0 ± 11.9	0.582	34.9 ± 25.8	43.8 ± 40.5	0.278
Sex	Girls (n = 20)	5.6 ± 7.2	7.7 ± 10.4	0.352	3.6 ± 4.9	9.1 ± 9.8	0.029	6.4 ± 5.6	9.6 ± 9.9	0.066	18.3 ± 9.1	23.3 ± 6.2	0.015	33.8 ± 12.9	49.6 ± 21.5	0.006
Grades	Lower (n = 11)	6.6 ± 9.6	6.6 ± 10.6	0.965	2.9 ± 7.4	7.3 ± 10	0.094	6.6 ± 9.1	8.3 ± 11	0.462	13.6 ± 11.9	12.3 ± 12.3	0.619	29.7 ± 28.8	34.5 ± 34.6	0.496
	Middle (n = 16)	7.3 ± 7.1	6.7 ± 9.7	0.801	3.3 ± 4.5	7.7 ± 8.7	0.062	5.4 ± 5.5	7.7 ± 8.4	0.258	17.5 ± 10.8	19.6 ± 10.3	0.429	33.4 ± 12.5	41.7 ± 25.7	0.171
	Upper (n = 10)	6.5 ± 6.8	16.5 ± 11.7	0.049	9.5 ± 7.4	12.1 ± 13	0.578	12.4 ± 4.4	16.7 ± 11.1	0.296	12.4 ± 10.4	23.7 ± 3.8	0.012	40.8 ± 16.7	69.0 ± 26.7	0.030
Diversity of vegetable side dishes per meal²⁾	2 or fewer types (n = 13)	6.6 ± 8.1	5.3 ± 9.1	0.579	1.6 ± 2.6	3.4 ± 5.2	0.282	4.2 ± 6.3	5.2 ± 7.5	0.656	15.5 ± 11.0	14.5 ± 12.5	0.801	27.9 ± 16.1	28.5 ± 26.2	0.929
	3 types (n = 12)	8.8 ± 7.2	8.8 ± 12.1	0.978	7.8 ± 7.8	8.9 ± 11.2	0.674	9.3 ± 8.1	9.3 ± 10.5	0.975	16.8 ± 11.3	21.8 ± 7.8	0.074	42.6 ± 26.8	48.8 ± 31.3	0.406
	4 or more types (n = 12)	5.2 ± 7.8	14.2 ± 11.1	0.017	5.5 ± 7.8	14.4 ± 11.0	0.034	9.7 ± 5.6	16.8 ± 10.5	0.014	12.7 ± 11.1	19.6 ± 9.8	0.041	33.0 ± 11.2	65.0 ± 26.8	0.002

Variables	Age	Awareness	Experience	Preference	Healthy eating efficacy	Diversity of vegetable side dishes per meal¹⁾	Total raw vegetable intake
Age	1
Awareness	0.047	1
Experience	0.326^*	0.495^**	1
Preference	0.353^*	0.297	0.257	1
Healthy eating efficacy	0.121	0.078	0.133	0.315	1
Diversity of vegetable side dishes per meal¹⁾	0.169	–0.036	0.038	0.447^**	0.471^**	1
Total raw vegetable intake	0.379^*	0.094	0.405^*	0.453^**	0.040	0.408^*	1

Independent variables	Model 1				Model 2				Model 3				Model 4				Model 5				Model 6
Independent variables	B	SE	t	β	B	SE	t	β	B	SE	t	β	B	SE	t	β	B	SE	t	β	B	SE	t	β
Sex¹⁾	0.769	7.015	0.110	0.017	1.347	7.189	0.187	0.031	0.553	6.915	0.080	0.013	2.246	6.531	0.344	0.051	1.856	6.566	0.283	0.042	–3.055	6.537	–0.467	–0.069
Age	5.419	2.290	2.367	0.377^*	5.346	2.320	2.304	0.372^*	3.766	2.371	1.589	0.262	1.905	2.367	0.805	0.133	1.889	2.374	0.796	0.132	2.048	2.229	0.919	0.143
Awareness					5.409	10.886	0.497	0.081	–6.650	12.150	–0.547	–0.099	–13.072	11.738	–1.114	–0.195	–13.695	11.795	–1.161	–0.205	–10.507	11.160	–0.941	–0.157
Experience									17.112	8.788	1.947	0.369	16.784	8.249	2.035	0.362	17.360	8.300	2.092	0.374^*	18.339	7.801	2.351	0.395^*
Preference													8.734	3.783	2.309	0.376^*	9.719	3.950	2.460	0.419^*	5.835	4.089	1.427	0.251
Healthy eating efficacy																	–4.557	5.068	–0.899	–0.138	–9.675	5.272	–1.835	–0.293
Diversity of vegetable side dishes per meal²⁾																					8.203	3.647	2.249	0.403^*
(Constant)	–10.503	23.039	–0.456	-	–36.674	57.595	–0.637	-	–42.817	55.393	–0.773	-	–28.859	52.338	–0.551	-	–13.374	55.253	–0.242	-	–15.376	51.863	–0.296	-
R²	0.144				0.150				0.240				0.352				0.369				0.462
△R²	0.094				0.073				0.145				0.247				0.242				0.333
F	2.857				1.945				2.530				3.363^*				2.920^*				3.565^**
△F	2.857				0.247				3.791				5.329^*				0.809				5.060^*

Table 1. Cooking-based nutrition education program for school-aged children

Table 2. General characteristics of the subjects and results of pre- and post- education questionnaires (n = 37)

n (%) or mean ± SD.

Number of types, including kimchi.

Table 3. Changes in raw vegetable intake before and after education (n = 37)

mean ± SD.

The significance level for statistical analysis was P < 0.05. Comparisons were performed using the paired t-test.

Table 4. Changes in raw vegetable intake before and after education according to sex, grades and diversity of vegetable side dishes per meal (based on the number of types)

mean ± SD.

The significance level for statistical analysis was P < 0.05. Comparisons were performed using the paired t-test.

Number of types, including kimchi.

Table 5. Correlation analysis between total raw vegetable intake and major variables (n = 37)

Number of types, including kimchi.

P < 0.05,

P < 0.01.

Table 6. Hierarchical regression analysis of major predictors on total raw vegetable intake (n = 37)