A Systematic Review of School-Based Nutrition Interventions for Promoting Healthy Dietary Practices and Lifestyle Among School Children and Adolescents

Childhood malnutrition is one of the foremost community health problems in the world, particularly in developing countries like India. This current review was conducted to evaluate the effectiveness of various school-centered nutrition interventions/intervention programs developed in recent years, and their impact on the nutritional status, dietary habits, food preferences, lifestyle, and dietary behaviors in relation to diet, as well as physical activities for school children, especially adolescents. This review included studies found in the PubMed/Medline, SCOPUS, and Web of Science (WOS) databases, published from July 2017 to 2023. They were analyzed for eligibility criteria defined for this study, including school children and adolescents, school-based nutrition interventions/strategies/policies/initiatives, nutritional status, physical activity, dietary habits, and lifestyle. The Risk of Bias assessment was conducted using Review Manager version 5.4. Among 1776 potentially related studies, 108 met the eligibility criteria. Following this review, 62 studies were identified as eligible for this study, in which 38 intervention programs were discussed. A total of 13 studies were considered comprehensive and multi-component, 15 were nutrition education interventions, six were identified as physical activity interventions, and four focused on lifestyle and dietary behavior-related interventions. Another 24 of the 62 studies reviewed (approximately 39%) were either original articles, review articles, or articles pertaining to nutritional program guidelines, protocols, and/or reports. These studies uncovered a possible relationship between a decrease in BMI and school children's engagement in diet and/or physical activity. Results also suggest that these programs can be effective, although evidence for the long-term sustainability of changes in BMI was less evident and not fully substantiated/supported. Most of these findings are based on self-reported program data and may consist of biases linked to recall, selection of participants, and the desire to report favorable final measures (physical activity, lifestyle, and dietary habits). This study has the potential for use in public health programs devoted to healthy nutrition behavior and lifestyle practices. This research was primarily conducted by clinical researchers and did not receive any standardized institutional or organization-derived grant funding and support.


Introduction And Background
Malnutrition among children in India is a crucial wellbeing issue [1].Both undernutrition and overnutrition have reached epidemic proportions in developing countries like India, where children and adolescents are most vulnerable.In these countries, wellbeing risks, especially related to malnutrition, are associated with poor and imbalanced nutrition, which are major causes of significant health concerns.These can further lead to slow cognitive and nervous system maturation [2].Wellbeing habits and behaviors are established in early childhood and continue into adulthood [3].In recent years, it has been observed that children's eating habits are influenced initially by family situations, with most changes occurring upon entering school, where they spend much of their time away from home [3].Therefore, health education in schools is of utmost importance to promote adolescent health.By distributing and utilizing reliable internet information sources and encouraging critical thinking, schools can also play a significant role in helping adolescents filter out false information [4].
Obesity is a preventable disease, but with the influence of a Western lifestyle (characterized by a sedentary lifestyle and large consumption of processed foods, high-sugar beverages, sweets, fried foods, and highfructose food items), its impact on the population is increasing dramatically.According to surveys conducted in Indian cities, the prevalence of overnutrition among school children is above 10%.Improved knowledge and behavior related to health and nutrition are highly associated with broad-level health and dietetics programs, especially in educational facilities in India [5].The scientific literature reveals that the problem of undernutrition remains significant in school children, contributing to 22% of the country's burden of disease [6].The prevalence of poor nutritional status among children and adolescents greatly hinders national advancement, both socially and economically.Essential nutrition interventions have a significant effect on reducing the severity of undernutrition in India (NFHS-5).Older children and teenagers receive less attention from well-being providers compared to under-fives, especially in developing countries [7].It is observed that at the personal level, weight loss interventions pointed at calorie input and output are frequently not fruitful in the long term.In this context, the Mid-day Meal Program, a multipurpose initiative of the Government of India, and the National Scheme known as PM Poshan (Pradhan Mantri Poshan Shakti Nirman) in schools are important policies addressing the nutritional needs of institute-going children, especially in the age group of 6-12 years, who are vulnerable to nutritional deficiencies with negative effects on growth and development [6].The Focusing Resources on Effective School Health (FRESH) framework, developed in the early 2000s and primarily aimed at addressing undernutrition, was a pioneering international framework linking nutrition and education.Later, in 2006, the World Health Organization (WHO) launched the Nutrition Friendly School Initiative (NFSI) to address the double burden of malnutrition.These two frameworks have laid the foundation for elements in schools that promote health [7], with support from the Food Safety and Standards Authority of India (FSSAI) and the Indian Academy of Pediatrics (IAP).
The findings indicate that nutritional status encompasses political, cultural, and social dimensions, supporting the need for multidimensional actions to enhance the dietary habits and lifestyle of school-going children and adolescents [8].The first step in developing such interventions is to reference research and create a model based on treatments that are efficient, effective, acceptable in a school context, and allow for easy outcome analysis [9].
It is critical to understand the effect of various interventions implemented at the school level to improve healthy dietary practices in the context of evolving school-based nutritional programs and policies [10].Hence, this present study aims to contribute to the literature from a different perspective by identifying only school-based interventional strategies and their effectiveness.These are directly engaged in promoting nutritional status, nutrition-related knowledge, dietary habits, lifestyle, and physical activity among schoolgoing children and adolescents and have not been sufficiently and particularly emphasized in other systematic review studies.The intervention programs have been selected and documented in the form of a systematic review to be used as a guide in producing strategies with the same goal, following the final selection and extraction of the data components and implementation techniques.This will assist community stakeholders in identifying gaps and undertaking further studies, as well as informing the development of intervention training programs that pursue altering dietary behaviors by endorsing better dietary habits in this populace clutch.

Review Methods
A systematic review has been conducted on various studies from all regions regarding school-based intervention strategies and their outcomes among school-going children and adolescents.

Selection Methods and Search Strategy
By following defined enrolment criteria, autonomously all dynamic titles, abstracts, and full-texts, including additional publications, were identified from the reference lists of these articles and these have been analyzed and interpreted accordingly.A PubMed, SCOPUS, and Web of Science (WOS) exploration scheme was established and amended to additional databanks as required in June and July 2023.All these articles were screened and explored to identify nutrition-related papers by researcher one.Articles that indicated different school-based intervention strategies, such as nutrition education, health promotion, physical activity, counseling, nutrition/lifestyle management programs, etc., for school-going children and youths with outcomes clearly identifiable as nutrition-related, were reviewed by researchers one and two.When necessary, each database's approach was adjusted.In-person searches of allusion lists of previously published analyses and of included papers were conducted to ascertain additional research works.This process yielded 62 related scientific papers.The literature selection strategy is presented in Appendix 1. Figure 1 represents the search strategy in the form of a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow chart.

Inclusion Criteria
Articles eligible for inclusion in this review met one or more of the following criteria: scientific literature involving school children aged six to twelve years and early and middle adolescents aged thirteen to seventeen years; studies that discussed or implemented any school-based strategy, intervention, policy, program, education, counseling, initiative, or technique; studies focusing on nutritional status, healthy eating, physical activity, dietary habits, food choices or preferences, and lifestyle; original and review articles, systematic reviews, government guidelines, protocols, or policies from July 2017 to 2023.

Data Extraction and Synthesis
A descriptive analysis was performed to extract data from each included study.The variables obtained from the selected articles were (1) Study details: author, year of publication, and country; (2) study setting and design; (3) intervention type; (4) study population: participants and their age during the intervention, along with gender; (5) sample size; (6) duration of intervention; (7) follow-up and number of dropouts; and (8) outcomes of the studies.The titles and/or abstracts and whole scripts of the relevant articles were evaluated by either author, and any inconsistencies were resolved by consensus between the authors or by both, according to the criteria for inclusion in the study.Table 2 displays the data extraction procedure.
Regarding study settings, all the included studies were conducted in schools or educational institutions, and they had outcomes such as nutritional status, knowledge, attitude, practices, dietary habits, diet pattern, food preferences or choices, nutrition-related knowledge, practice of healthy eating, lifestyle, and behavioral change in relation to nutrition, physical activity, and body composition (BMI, WHO Growth References).Table 3 provides a summary of the key characteristics of the included studies, and Table 4 presents strategies in different combinations in multi-component school programs.

Discussion
This systematic review is an effort to bring together various evidence-based studies on effective schoolbased nutrition interventions that promote healthy dietary practices, food preferences, lifestyle, diet-related behavior, and knowledge, as well as the nutritional status of school children and adolescents.It has been found that health and nutrition-related intervention programs significantly impact the health, knowledge, lifestyle, and behavioral status of school-aged children and adolescents in relation to dietary habits.This underscores the need to increase mindfulness about the benefits of including whole foods in daily diets [7,8,10,11]

Type of Interventions and Their Combinations
Multi-component interventions: Among the evaluated studies, 13 were comprehensive multi-component interventions [8][9][10][11][12][13][14][15][16]31,34,52,55].These trials impacted BMI, understanding of nutrition, practice of healthy eating, dietary diversity, level of physical activity, self-efficacy for exercise, waist circumference, and personal hygiene.Nutrition and health education using a problem-raising approach, utilization of visual aids like flip charts and picture representations, and lifestyle and behavioral intervention in combination are consistent improvement characteristics across trials [8,9,11,12,14].These studies also show that health education based on an interactive, participative, problem-raising strategy with the use of food illustrations, combined with physical exercise, can affect dietary intake.

Nutrition Education
Among the evaluated studies, 15 focused on nutrition education interventions [17,[19][20][21][23][24][25][26][27]51,57,[59][60][61][62].These studies were classified according to their direct focus on nutrition education.One common factor for improvement was a structured nutrition education program with interactive discussion, practical nutrition lessons, and a dedicated time slot led by professional, trained school teachers and trained peers [15,18,21,24,52].The impact of these activities is mostly a change in dietary habits and nutrition-related knowledge, justifying the success of these components.The educational activities in the classroom are based on formal education, employing organized material with precise objectives to transmit knowledge about the benefits of eating right.

Physical Activity Interventions
A rise in physical activity and a decline in sedentary behaviors have been identified in six studies [28,32,35,36,38,54].A self-sustaining, school-based physical activity program run by experts and qualified school teachers with strong nutritional knowledge has been found to be one of the common improvement factors across these studies [28,32,35,36,38,54].This underlines the importance of implementing interventions that not only concentrate on enhancing a single healthy habit but also design dietary strategies aimed at adopting an overall healthy lifestyle, including physical activity.In this regard, current research shows that addressing two health behaviors simultaneously with a multidisciplinary approach may have an indirect or synergistic impact [14,45,48].BMI and waist circumference were found to have changed in 25 of the analyzed studies [8,9,12,14,17,18,20,21,25,26,[28][29][30]32,34,35,[44][45][46][47][48]50,[53][54][55] after implementing a physical activity intervention program.
Four of these studies [10,49,51,52], which used self-report methods to assess changes in health behaviors, revealed no significant changes in BMI and waist circumference.They also had a low retention rate at follow-up, failed to account for a significant number of trials, tracked weight using BMI and waist circumference restrictions, which made it impossible to determine the best possible outcomes, and had a strained intervention that might not be generalizable to other populations.This highlights the need for thorough follow-up, standardized testing, generalizable intervention programs, and the consideration of socioeconomic status in achieving the best outcomes.

Lifestyle and Nutrition-related Behavior Intervention
Lifestyle and behavioral interventions, such as altering eating habits, eating behaviors, and awareness of health risks, significantly improved nutrition-related knowledge, attitude, and practice in healthy lifestyles among school-aged children and adolescents, as demonstrated by four studies [40,42,43,53].A systematic and well-organized lifestyle intervention program was attributed in one research noted by Sharif Ishak SI et al., 2020 [40] to a decrease in abdominal obesity; this conclusion is also supported by the findings of studies conducted by Kamin T et al., 2022 [42].These findings imply that lifestyle programs that do not just concentrate on diet are more successful [14][15][16].
It is important to highlight in the common findings that the effects of interventions tend to diminish over time [8,10,12,14,21,24,25,32,34,38].In this respect, it might be assessed to see if the newly learned healthy behaviors are maintained over time, especially after the intervention is complete, as this is the major goal of any research.A recent study that looked at the effect over time of an educational intervention on diet, physical activity, and BMI in children, including adolescents, discovered that the intervention was still effective after two years [31].In one multi-component nutrition intervention research on BMI by Scherr RE et al. in 2017, significant results were shown one year after the intervention [9].Improvements in weight were seen in both investigations.
There was consistency in the approach used to evaluate participants' nutrition knowledge through the use of various questionnaires [8,9,12,14,16,17,20,24,25,27,28,36,40,43,[51][52][53][54][55][56][57]59,61,62].Every type of questionnaire used with children and adolescents follows a proven approach.Although there are several types and proven models for each, there is no consensus on the best method to assess nutritional knowledge.Using questionnaires has drawbacks, as the information gathered may be skewed, among other issues.However, studies have demonstrated that school-age children and teenagers, even as young as six years old, are capable of responding to questions about themselves, including those about their health and nutrition [31].
Figure 3 shows the relationship between intervention components and outcomes.

Risk of Bias assessment
The Risk of Bias (RoB) assessment has been conducted using Review Manager version 5.4.Figures 4 and 5 illustrate the risk of bias graph and the risk of bias summary of the included studies, respectively.The RoB assessment aims to assess the risk of bias for each of the seven domains in the RoB1 tool.These domains include bias arising from inadequate generation of a randomized sequence; bias due to inadequate concealment of allocations prior to assignment; bias due to knowledge of the allocated interventions by participants and personnel during the study; bias due to knowledge of allocated interventions by outcome assessors; bias due to the amount, nature, and handling of incomplete outcome data; bias due to selective outcome reporting; and any other bias not mentioned above.The signaling questions 'bias arising from inadequate generation of a randomized sequence' and 'bias due to inadequate concealment of allocations prior to assignment' were most often identified.This was in part because studies did not clearly report how the allocation sequence was generated and concealed.Other biases amongst the studies are due to the measurement of outcomes, such as self-reported dietary habits, physical activity outcomes, recall bias, social desirability bias, and others [14,15,17,21,25,32,34,36,42,61].Furthermore, a few studies failed to explain their sample size estimation [14,17,25,34,36,42].The lack of information reported in studies regarding certain domains might have masked underlying biases that could not be identified.Green: Low risk of bias; Red: High risk of bias; Yellow: Unclear risk of bias.

Advantages and Limitations
The key advantage of our review is the systematic search strategy performed, which makes it less likely to overlook important regional studies.It also offers many other advantages.For example, this review provides a thorough and current assessment of this subject; it analyzes and assesses each of the factors that can contribute to the success of these techniques; it notes the presence of follow-up sessions, along with the size of the sample and the length of the intervention in the studies that were chosen; it demonstrates the reliability of the data, has used three databases (PubMed, SCOPUS, WOS), and includes 62 related articles.
Additionally, this systematic review has a few limitations.Firstly, most findings are based on self-reported data and, hence, have biases such as recall bias, selection bias, and social desirability bias.Secondly, as some studies implemented a multi-interventional program, it is difficult to determine the extent to which reductions in anthropometric markers, e.g., BMI and waist circumference, were due to the physical activity intervention as distinct from other components (such as dietary habit change).Thirdly, further research will be required to determine the relative effects of physical activity interventions alone, both quantitative and qualitative, or a combination, when compared to those of nutrition interventions alone or in combination with each other.

Conclusions
This systematic review has found that improving both short-and long-term eating behaviors in schoolchildren and adolescents may be accomplished through interventions that alter their environments.However, it is also apparent that the majority of research have not concentrated on various contextual factors, which may have a significant impact on the efficacy of various nutritional interventions.To improve young adolescents' and school-age children's overall health and nutritional status, it is crucial to concentrate on and plan cost-effective, thorough, multi-strategic intervention studies.Exploring strategies that incorporate each of the components stated below might be intriguing to have a greater impact on the nutrition and health of schoolchildren and the teenage population: (a) approaches that emphasize acquiring a healthy lifestyle overall rather than only changing eating practices, including physical exercise as part of the intervention; (b) due to the significant influence parents have on their children's eating habits, interventions that focused on the school and the settings of children engaged parents in the intervention; (c) techniques that incorporate health knowledge, such as classes on nutrition; and (d) techniques that assess long-term impacts after an intervention is complete to see if the positive outcomes are sustained over time.However, it would be intriguing to examine the potential implications of these approaches on other parameters, like changes of body mass and constituents or biomarkers.
Ideally, this review should assist community stakeholders, such as school administrators, teachers, students, parents, policy makers, health professionals, health educators, and research materials in framing the National Nutrition Education Programs.Such programs address the unfinished agenda of interventions needed to address the dual burden of malnutrition among schoolchildren and adolescents for improving the health status of the community as a whole.Even though school-based nutrition programs have evidence suggesting they can in theory be effective, evidence of the long-term sustainability of these programs has yet to be studied or reviewed in any formidable detail.

Literature Selection Strategy
Electronic databases have been used to enable a thorough, systematic investigation into research like PubMed/ Medline, SCOPUS, WOS and was searched until 2023 July to identify relevant studies.Exploration was restricted to journals with tutelages available in English and English titles, abstracts and keywords with phrases such-as "body mass index/BMI", "Underweight/ under-nutrition", "Obesity", "Malnutrition", "School", "Lifestyle", "Dietary habits", "Food choices", "Physical activity", "Personal hygiene", "Children", "Adolescent", "Risk factors", "Intervention", "Strategies", etc. Web of Science (WOS) search is standardized appropriately: nutrition intervention (Topic) and school (All Fields) and children (All Fields) and adolescents (All Fields) and habits (All Fields) and dietary (All Fields).

FIGURE 1 :
FIGURE 1: Conceptual framework and search strategy (PRISMA flow chart).PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

FIGURE 2 :
FIGURE 2: Conceptual framework of the methodology.

FIGURE 3 :
FIGURE 3: Relationship between intervention components and outcomes.

FIGURE 4 :
FIGURE 4: Risk of bias graph about each risk of bias item presented as percentages across the included studies.

FIGURE 5 :
FIGURE 5: Risk of bias summary of each risk of bias item for included studies.