The Let’s Eat Healthy and Move at School program for adolescents in South Korea: Program design, implementation, and evaluation plan using intervention mapping

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Child Health Nurs Res. 2021;27(3):225-242

Publication date (electronic) : 2021 July 30

doi : https://doi.org/10.4094/chnr.2021.27.3.225

Jiyoung Park¹, Gill A. Ten Hoor², Seolhyang Baek³, Sochung Chung⁴, Yang-Hyun Kim⁵, Gahui Hwang^,6

¹Assistant Professor, College of Nursing, Institute for Health Science Research, Inje University, Busan, Korea

²Assistant Professor, Department of Work and Social Psychology, Maastricht University, Maastricht, Netherlands

³Professor, College of Nursing, Dongguk University, Gyeongju, Korea

⁴Professor, Department of Pediatrics, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea

⁵Associate Professor, Department of Family Medicine, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea

⁶Graduate Student, College of Nursing, Yonsei University, Seoul, Korea

Corresponding author Gahui Hwang College of Nursing, Yonsei University, 50-1 Yonsei-ro, Seodaemun-gu, 03722 Seoul, Korea TEL: +82-51-890-6079 FAX: +82-51-896-9840 E-MAIL: hwang_dawn@naver.com

Received 2021 April 26; Revised 2021 June 7; Accepted 2021 July 14.

Abstract

INTRODUCTION

According to the United States Centers for Disease Control and Prevention, the prevalence of obesity in 2017-2018 was 19.3% among children and adolescents aged 2-19 years old. It was even higher (21.2%) among adolescents aged 12-19 years old, particularly compared to children aged 2-5 years (13.4%) and 6-11 years (20.3%) [1]. In South Korea, the obesity prevalence among children and adolescents has steadily increased from 8.5% in 1998 to 10.2% in 2010 and 11.5% in 2018 [2]. According to the Korea Youth Risk Behavior Web-based Survey [3], the obesity rate of adolescents was 5.1% in 2009, 7.5% in 2016, and 12.1% in 2020. These data provide evidence showing an increase in the obesity rate, which is likely in part due to high academic workloads, needing excessive time to devote to study, and a decrease in physical activity as adolescents in Korea move on to higher grade levels [4]. An increase in the rate of overweight and obesity will lead to further health problems for adolescents such as asthma, joint problems, type 2 diabetes, depression, anxiety, and sleep apnea, and can negatively affect academic achievement due to disease-related absences from school [5]. In addition, obese adolescents have a high rate of various psychosocial problems, bullying, bipolar disorder, schizophrenia, and even suicidal thoughts [6]. Neglecting obesity during adolescence will likely lead to obesity in adulthood and comorbidities of obesity-related diseases such as diabetes and hypertension [7].

Adolescent obesity is affected by both individual and environmental factors [4]. The individual factors include excessive academic stress, which can lead to unhealthy eating behaviors and a sedentary lifestyle, such as the development of a gaming or internet addiction [8]. Moreover, physical inactivity also tends to be high among adolescents who frequently consume fast food [9]. From an environmental point of view, the home environments of adolescents, including being from a low-income household or experiencing poor living conditions, and a lack of opportunities for physical activity at school [4,10] ultimately accelerate the risk of obesity and obesity-related diseases.

Among the various factors that influence adolescent obesity, schools are an important setting within which adolescents can shape obesity-related behaviors [11]. Adolescents spend most of the day at school, and schools offer two meals per day and opportunities for physical activities through physical education classes and break time [11]. Given these circumstances, the United Kingdom has begun to promote various programs at the school level to emphasize healthy living practices. Adolescents who live short distances from their schools are encouraged to walk to school, and students who ride a car to school are encouraged to exit the vehicle at a certain distance from the school and walk the rest of the way for a total of at least 10 minutes [12]. In the United States, administrators installed vending machines that sell healthy foods [13]. Policy-makers in Australia have also undertaken strategies to foster a healthy environment for children and adolescents by implementing school- based programs, among various other strategies, to mitigate the adolescent obesity problem [14]. These examples suggest that many other countries have begun to implement school-based obesity prevention programs with great variety. However, in Korea, few systematic obesity prevention management programs with long-term goals have been developed. In addition, since the school environment in Korea is different from that in other countries, obesity prevention and management programs adapted to the characteristics of the Korean school environment urgently need to be developed. The school environment is vital for the effective prevention and management of adolescent obesity since adolescent obesity involves not only behavioral factors at the individual level, such as poor eating habits and a lack of physical activity to increase energy intake and reduce energy consumption, but also various factors at the environmental level that affect adolescents' physical activity and eating habits [15,16].

Despite the need for adolescent obesity prevention measures, a systematic review on childhood obesity interventions in Korea found that, out of 192 studies from 1996 to 2015, only nine studies (4.7%) involving adolescents and four (2.1%) involving elementary school students and adolescents have been conducted on the topic [17]. In addition, a total of 14 studies (published between 1994 and 2014) that involved adolescent obesity patients were reviewed in research that analyzed the status of adolescent obesity management programs conducted at domestic healthcare institutions [18]. According to this study, eight of the 14 obesity management programs that were implemented were complex programs that combined exercise and education, with nine of the programs having been implemented at general hospitals and five having been conducted at local health centers. While there have been some studies that have targeted adolescents in domestic settings [19,20], these studies have focused on adolescent obesity management rather than obesity prevention. Moreover, there have been no studies emphasizing the role of schools in the daily lives of adolescents concerning obesity prevention, even though schools are where adolescents spend most of their time.

1. Intervention Mapping

Intervention mapping (IM) [21] is a widely used protocol for developing tailored interventions using community-based participatory research. Taking an iterative approach, IM offers a structure for systematically developing interventions from problem identification to problem-solving or mitigation (Figure 1). The six steps of IM comprise several tasks, each of which integrates theory and evidence. The completion of the tasks within a step results in the creation of a product that guides the subsequent step. The completion of all of the steps leads to the creation of a blueprint for designing, implementing, and evaluating an intervention based on theoretical, empirical, and practical information. This sequential description of the program components is intended to address the effects of individual and environmental-level determinants, and the behaviors, outcomes, health, and quality of life of the target population [21]. IM has been used as an important method for carrying out various projects worldwide [16] and is expected to be used more extensively in the future.

Figure 1.

Six steps and tasks of intervention mapping.

In conclusion, developing a school-based obesity prevention program for adolescents in Korea is essential, and this study aimed to initiate a systematic process for developing such a program using IM.

METHODS

RESULTS

2. Step 2: Program Outcomes and Objectives - Logic Model of Change

In this study, an intervention logic model was constructed for program development directed at the most relevant determinants, based on the theory of planned behavior [22] and the reasoned action approach [23]. Figure 2 shows the logic model of change. The Let's Eat Healthy and Move at School program-a school-based obesity prevention program for adolescents-is expected to improve program participants' awareness, risk perception, skills and self-efficacy, attitude and outcome expectations for obesity prevention, and obesity prevention-related behaviors (healthy eating and physical activity). These psychosocial determinants are measurable as immediate outcomes. Changes in these psychosocial determinants affect adolescents' intentions to adopt healthy lifestyles (intermediate outcome), which are key for encouraging actual behavioral changes, and ultimately inspire individuals to adopt healthy diets and increase their physical activity (behavioral outcome).

Figure 2.

Logic model of change of this study. OP, obesity prevention; OPBs, obesity prevention-related behaviors.

The matrix of this study consists of three POs, six individual determinants, and 16 COs. The three POs are shown in Table 1: 1) find out the why and how of obesity prevention, 2) eat healthy meals and snacks in school, and 3) increase the level of physical activity in school. In addition, six individual determinants, including awareness and risk perception (AR), skills and self-efficacy (SSE), and attitude and outcome expectations (AO) are shown. COs were created at the point where the POs and determinants converged.

Table 1.

Matrix of Change Objectives for the Let’s Eat Healthy and Move at School Program Targeting Students

3. Step 3: Program Design

The theoretical methods used in this study were persuasive communication, raising consciousness, individualization, planning coping responses, feedback, goal setting, and facilitation. The theory-based methods and practical applications applied for each determinant are shown in Table 2. Theoretical methods were assigned to corresponding COs, such as goal setting and feedback, which were applied to CO SSE2.3 ("Express confidence that students can eat healthy meals and snacks in school"). Program participants recorded their goals concerning healthy eating at school in a workseet and gave presentations on those goals, for which they received individual feedback. In addition, the theoretical methods of persuasive communication and facilitation were applied to CO SSE3.1 ("List ways to increase the level of physical activity level in schools"). School program instructors provide lectures on how to improve physical activity in school and conduct in-school campaigns such as displaying posters encouraging physical activity and providing students with elastic exercise bands that could be used easily at any time to promote their physical activities.

Table 2.

Theoretical Methods and Practical Applications Related to the Let’s Eat Healthy and Move at School Program

6. Step 6: Evaluation Plan

A self-report questionnaire survey to be conducted before and after program implementation was designed to evaluate the program's effectiveness. The Obesity Prevention-related Behaviors Intention Questionnaire-a survey instrument for measuring the immediate and intermediate outcomes in the logic model of change (Figure 2)-was developed based on the program matrix (Table 1) using the method suggested by Fishbein and Ajzen [23]. They outlined how to construct questionnaire items based on each determinant and suggested a 7-point Likert scale for rating them. The instrument in this study was designed to consist of 11 items to measure the psychosocial determinants of obesity prevention behaviors in adolescents, including their awareness and risk perception (4 items), skills and self-efficacy (2 items), attitudes and outcome expectations (3 items), and intentions (2 items) (Table 3). The contents of these items were reviewed by one health psychology expert and two medical doctors who specialized in childhood obesity. Each item was designed to be rated on a 7-point Likert scale with possible scores ranging from 11 to 77 points, with a higher score indicating a greater intention to adopt behaviors to prevent obesity. In addition, the behavioral outcomes in the logic model of change (Figure 2) were measured using the Nutrition Quotient for Adolescents [24] and Korean Youth Physical Activity Questionnaire [25].

Table 3.

Questionnaire Items Based on the Program Matrix in Step 2

A post-participation satisfaction survey designed to be completed by program participants was developed for evaluating the program process. The program satisfaction survey comprised nine questions to evaluate participants' satisfaction concerning the program's contents and operation, as well as their willingness to participate in the program again, and included a blank section where participants could answer in their own words what they felt and thought about the program. Each item was designed to be measured on a 5-point Likert scale, with total possible scores ranging from 9 to 45 points and a higher total score indicating greater satisfaction with the program.

DISCUSSION

The Let's Eat Healthy and Move at School program was developed using the six steps of IM, an advanced health planning methodology. In this study, the entire session was organized in accordance with the six steps of IM, and the objectives, interventions, and scope of each session were specified. The program planning team was organized with the input of multidisciplinary experts. In step 1, the problems and actual conditions of adolescent obesity were identified based on in-depth interviews with various stakeholders on the topic of adolescent obesity. In step 2, findings from the needs assessment were translated into a matrix of COs. In step 3, suitable theoretical methods and applications were matched to the COs established in the previous step. The program was designed and organized in step 4, and an operation manual was developed for prospective program instructors in step 5. Lastly, methods to evaluate the program's effectiveness and process were devised in step 6. These steps resulted in the creation of a program comprising three in-school sessions that include educational activities and an in-school campaign to prevent adolescent obesity through the adoption of healthy eating habits and the promotion of physical activities at school.

IM is a planning framework that provides a systematic process and detailed protocol for effective step-by-step decisionmaking in the development, implementation, and evaluation of interventions. It is actively used around the world for developing various health promotion programs for children and adolescents [41]. For example, a community-oriented obesity prevention program for children aged 2-9 years was developed, implemented, and evaluated across eight European countries (Sweden, Germany, Hungary, Italy, Cyprus, Spain, Belgium, and Estonia) as part of the Identification and Prevention of Dietary- and Lifestyle-induced Health Effects in Children and Infants (IDEFICS) longitudinal study [42], which was conducted from September 2006 to February 2012 and led to the ratification of the IDEFICS Charter. The IDEFICS was formally launched in Sweden in May 2011 and has since been consulted by various local communities, politicians, and policy legislators interested in preventing childhood obesity for its evidence-based guidelines [42]. In the Netherlands, a protocol for a school-based program aimed at improving the quality of life of overweight adolescents by promoting physical activity was developed and conducted in 2016 [16], and an obesity prevention intervention program was developed in 2019 for children aged 9-12 years who reside in low-socioeconomic status areas to improve their health behaviors [10]. Thus, IM has been actively used for developing and evaluating health promotion programs in many countries.

In contrast, there have been few domestic studies to systematically apply IM in Korea. One of the few Korean studies to use IM was Hwang's 2021 study [43] on the development and effectiveness of a program to promote the obesity prevention behaviors of preschool children [21]. In Hwang's study [43], a program was developed to improve the eating habits, physical activities, and sedentary behaviors of preschool children. The program consisted of eight sessions across four weeks, was designed using IM, and used various intervention strategies (e.g., lectures, activities, and practice). As already mentioned, IM provides a systematic process for changing the behaviors of participants and has the advantage of being widely applicable for programs targeting various groups (e.g., children, adolescents, and parents) and environments (e.g., schools and community organizations). In this respect, the present study is significant in that it used IM to systematically develop an obesity prevention program aimed at changing adolescents' behaviors (healthy eating habits and physical activities). It is expected that IM will continue to be actively used for developing theory- and evidence-based programs in the area of child health promotion.

In order to effectively prevent and manage obesity in adolescents, it is necessary to reinforce a healthy lifestyle in schools and foster a healthy school environment in addition to providing support to individual students. Schools are especially important for the prevention and management of adolescent obesity, particularly in Korea, since Korean students are highly prone to obesity due to a significant cultural emphasis on schoolwork, widespread unhealthy eating habits and sedentary lifestyles, and long school hours compared to students in other countries [4,8]. The recent surge in the adolescent obesity rate further indicates an urgent need for interventions. Various efforts have been made internationally to foster healthy school environments, such as installing vending machines with healthy snack options [13] and encouraging students to walk to school to increase their physical activity [12]. Finland, in particular, was able to reduce the obesity rate among Finnish children from 16.1% to 8.2% in just 3 years by implementing a national action program called "Schools on the Move" [44]. Thus, interventions and strategies must be implemented with urgency in Korea to reduce the rapidly increasing adolescent obesity rate. In conclusion, this study is significant since it is the first to apply the IM health planning methodology to the development of an adolescent health promotion program in Korea, and since it encourages students to independently practice healthy eating habits and participate in physical activities in schools, where adolescents spend the most time.

Nevertheless, the program developed in this study has some limitations. First, according to the ecological model of McLeroy et al. [45], behavioral changes in individuals are much more effective when they coincide with changes in the environment. The program in this study primarily focuses on individual changes in obesity prevention behaviors and should be modified and supplemented in the future with programs that incorporate changes in the actual environments that surround adolescents (e.g. parents, teachers, and the school environment). Second, the program was developed as a short-term program comprising three sessions due to constraints in the research conditions such as a limited development period and budget. Therefore, long-term programs are also needed to ensure more active, long-term behavioral changes in adolescents. In particular, programs that take into account the preferences of adolescents, such as apps, mobile-based elements, and social media services, in their practical applications are needed. Moreover, the program should be supplemented with different elements according to the degree of obesity among the target population (obese, overweight, and normal-weight groups, as well as underweight groups). Third, in this study, we developed a matrix according to the methods proposed by Fishbein and Ajzen [23], upon which the development of our tool was based. Therefore, the reliability and validity of the tools still need to be tested in the future. Lastly, changes in adolescents' health behaviors, health problems, and quality of life, as well as changes in the school environment resulting from the program, need to be longitudinally evaluated.

CONCLUSION

In this study, the Let's Eat Healthy and Move at School program was developed according to the six steps of IM, an advanced and widely used health promotion planning protocol. This study is meaningful in that an adolescent obesity prevention program was systematically developed by following all six steps of IM, which reflects the needs of schools, thus increasing the program's practical utility. Preliminary evaluation of the program developed in this study will provide multi-dimensional verification of its applicability in the school setting. In addition, a plan to link programs between public health centers and schools should be devised to revitalize youth obesity prevention programs. The program developed in this study will be a significant contribution to adolescent obesity prevention.

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