Background and rationale {6a}
Malnutrition is one of the public health problems and causes of death among children in the world [1]. The World Health Organization (WHO) defines the term “malnutrition” both as nutritional deficiency, including thinness, underweight, stunting, and lack of micronutrients, and as overnutrition, including overweight and obesity. The WHO estimated that in 2019, 144 million children under the age of 5 were stunted, while 47 million children were classified as low weight for height [2]. The prevalence of malnutrition in Iran is based on weight for age, height for age, and weight for height, which are 19%, 20%, and 12.5%, respectively [3].
Height-, weight-, and BMI-for-age are key indicators of child nutrition; deficits lead to stunting, underweight, and thinness [4]. Malnutrition increases risks of infection, growth and cognitive delays, and mortality [5]. Contributing factors include poor socioeconomic status, low maternal education, hygiene issues, disease, limited health access, and inadequate feeding practices [6, 7]. Due to rapid growth in childhood, risks are heightened [3]. School children often skip breakfast, eat few fruits/vegetables, and consume unhealthy snacks [8]. Maternal nutrition education tailored to cultural and economic contexts improves child growth outcomes [9], while school-based programs and maternal education enhance dietary habits and development [10, 11].
The study was initiated following preliminary observations of nutritional challenges among primary school students, with particular attention to suboptimal nutrition-related quality of life and the prevalence of unhealthy dietary behaviors. This empirical observation was subsequently confirmed through community insights and epidemiological evidence from a large-scale study in south‑east Iran (n = 780), which reported the prevalence of severe wasting (0.8%), wasting (4.6%), overweight (6.4%), obesity (5.0%), severe underweight (0.9%), underweight (4.7%), severe stunting (0.3%), and stunting (2.8%) among primary school children [3]. Clinical observations further linked these malnutrition patterns to unhealthy dietary behaviors shaped by environmental and cultural factors [12]. A detailed diagnostic assessment identified multiple modifiable determinants across three levels: (i) individual factors—insufficient knowledge [13], unfavorable attitudes [14], low self‑efficacy [15], and unhealthy eating behaviors [16]; (ii) interpersonal factors—limited family support [17] and insufficient peer support [18]; and (iii) environmental factors—inadequate resources, limited skills, and restricted access to healthy foods [19]. Given these multifactorial influences, we recognized the need for a structured framework to integrate predisposing, enabling, and reinforcing factors in both planning and evaluation.
To validate our methodological approach, we conducted a systematic literature search across PubMed, Scopus, and Google Scholar using targeted keywords related to health education, behavior change, and nutrition (Supplemental page 1). Our review of individual-level models, as detailed in Supplemental Table 1, revealed a consistent pattern of limitations. Studies utilizing the Health Belief Model (HBM) and Theory of Planned Behavior (TPB), while effective in boosting knowledge and intention, frequently suffered from short follow-up periods, limited family involvement, and a failure to address structural barriers like access to affordable healthy food [20, 21]. Similarly, interventions based on the Transtheoretical Model (TTM) and Self-Determination Theory (SDT) were often constrained by high attrition rates, reliance on self-reported data, and an inability to sustain behavior change long-term because the broader supportive environment was not targeted [22, 23]. The Integrated Behavioral Model (IBM) also showed limitations related to short-term follow-up and uncertain generalizability beyond single-center studies [24]. This collective evidence underscores a critical gap: individual-focused models are insufficient on their own because they neglect the powerful enabling and reinforcing factors in a child’s environment. Even interpersonal-level models like Social Cognitive Theory (SCT), which incorporate social support, often lack a formal mechanism to address systemic issues [25]. While they bridge the gap between the individual and their immediate social circle, they do not provide a structured roadmap for diagnosing and integrating the necessary organizational support, resource allocation, and policy changes within institutions like schools that are essential for creating a truly enabling environment.
The fundamental and recurring limitations identified in our analysis—namely, the lack of integration between individual, social, and environmental/policy factors—led us to select the PRECEDE-PROCEED model. As an ecological framework, it not only accommodates but mandates a multi-level diagnosis. Its distinct advantage lies in its structured sequence of diagnostic phases, which systematically bridge the gaps identified in other models: It integrates predisposing factors (knowledge, attitudes, self-efficacy) addressed effectively by individual models [13]. It incorporates reinforcing factors (family, peer, and teacher support), central to interpersonal models [13]. Crucially, it introduces enabling factors and a formal Administrative and Policy Diagnosis (Phase 5), forcing an upfront analysis of the real-world resources, organizational capacity, and supportive policies needed for sustainable change—precisely the elements missing from the other frameworks reviewed.
Our comprehensive search for a suitable framework led us to the PRECEDE–PROCEED model, which applies a reverse‑planning logic—diagnosing social, epidemiological, behavioral, and environmental issues before implementation—and allows integration of individual, interpersonal, and environmental strategies [12,13,14,15]. Its ecological perspective, comprehensiveness, and demonstrated effectiveness in child nutrition interventions in diverse contexts [14, 16,17,18] make it especially well‑suited to the complex challenge of addressing malnutrition in primary school children. This comprehensive diagnostic process ensures that our intervention is not merely educational but is structurally supported, addressing the complex interplay of individual, social, and environmental determinants of child malnutrition in the Iranian context.
Previous studies have examined the impact of nutrition education on child health outcomes using behavioral models such as PRECEDE-PROCEED. For example, a trial (2014) reported significant improvements in behavioral determinants and weight gain among Iranian infants following a model-based intervention [16]. Li et al. (2022) similarly found enhanced maternal care competencies in the context of infant care [17]. However, other studies, including those by Antwi et al. (2020) [18] and Mushaphi et al. (2015) [19], reported improvements in knowledge and attitudes without corresponding changes in dietary diversity or anthropometric indices. Despite growing evidence, notable gaps persist. Few studies have integrated culturally adapted nutrition education with structured behavioral models in middle-income contexts [26]. Moreover, limited research has simultaneously addressed both dietary intake and growth indicators in school-aged children, particularly using national dietary guidelines such as Iran’s optimal food basket. This study seeks to address these gaps by evaluating a PRECEDE-PROCEED-based nutrition education intervention tailored to the Iranian context. By targeting malnourished children aged 7–12 in Kermanshah and aligning the intervention with national dietary recommendations, the study aims to contribute a model for improving both nutritional intake and growth outcomes.
Objectives {7}
The primary objectives of the study will be to determine the average scores of the PRECEDE model, including predisposing factors (knowledge, attitude, and self-efficacy), reinforcing factors, enabling factors, and behavioral assessment. Furthermore, the secondary outcome will be to assess the average growth indices (height for age, weight for age, and BMI for age) in both groups before and after the intervention.
Study hypotheses
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Primary hypothesis: Increased maternal knowledge and self-efficacy will lead to improved feeding practices and nutritional outcomes.
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Secondary hypothesis: Maternal nutrition education using the PRECEDE-PROCEED model will significantly improve child growth indicators.
Trial design {8}
The current study is a parallel-arm, open-label, randomized clinical trial that will be conducted on 254 children aged 7 to 12 with malnutrition who are randomly divided into two groups of 127 intervention and control. Our target group is children, and educational concepts will be simplified before being taught to them. Additionally, questionnaires will be filled out by the children after the researcher and teachers have conceptualized the questions appropriately. The intervention group will receive nutrition education for 8 weeks, and the control group will not receive any education. This study will be conducted based on the Precede-Proceed model, which consists of 9 steps:
Step 1: It is a social assessment that examines the quality of life of the community population, and demographic information will be assessed to begin planning.
Step 2: Epidemiological assessment is a complete description of the health problem and its occurrence in the study population, including mortality rates, prevalence, impact on individual functioning, and severity of disability. In this stage, we will examine prevalence and measure growth indicators (height for age, weight for age, weight for height, body mass index for age).
Step 3: Behavioral and environmental assessment, which includes examining behavioral factors on health problems (malnutrition), such as unhealthy eating. In this section, the 3-day food diary record will be used to examine the nutritional status of children. Since our goal is not to influence environmental factors, only behavioral factors will be examined in this section.
Step 4: Educational and ecological assessment, in which factors that can influence health behavior, including predisposing factors (knowledge, attitude, and self-efficacy), reinforcing factors (influence of others, family members, and peers), and enabling factors (availability of resources and skills), are examined and assessed using the PRECEDE questionnaire.
Step 5: Administrative assessment and policy review, which includes assessing and measuring administrative, organizational, and resource facilities for developing and implementing a program, and the limitations related to resources, policies, facilities, etc., that are being examined. In the present study, coordination with educators, school administrators, teachers, and parents, scheduling, budgeting, and coordinating the location and time of training sessions are carried out.
Step 6: The implementation phase is when the intervention group will undergo a training program that, based on the information from the initial questionnaire, will first assess educational needs, prioritize these trainings, and determine educational goals. Then, these trainings will be conducted through face-to-face lectures, group discussions, worksheets, questions and answers, and educational videos with the presence of students, their parents, and teachers.
Step 7: Process evaluation includes evaluating policies, resources, staff, service quality, and program implementation. In this study, for the process evaluation phase, research team members will review the implementation process, service quality, and behavior of the intervention group every week, and the pilot steering group will hold meetings to monitor data during the implementation phase.
Step 8: Outcome evaluation, which includes evaluating the program’s effects on intermediate objectives such as changing predisposing, enabling, reinforcing, and behavioral factors, will be conducted using questionnaires and statistical analyses.
Step 9: Outcome evaluation, which includes evaluating the final and long-term effects of the program and comparing it with the final goals, such as changes in quality of life, health, and social indicators, will be conducted using questionnaires, measuring anthropometric indicators, and statistical analyses.
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