Nutrition knowledge, attitude, and practice in relation to health-related quality of life among urban-poor children in Malaysia: the mediating role of lifestyle factors

Abstract

Background

Children living in urban-poor communities are particularly vulnerable to poor health-related quality of life (HRQoL) because socioeconomic disadvantage, food insecurity, constrained food environments, and limited access to health-promoting resources may affect both nutritional status and psychosocial well-being. Although nutrition knowledge, attitude, and practice (KAP) are known to influence children’s health behaviours, the behavioural pathways through which these factors affect HRQoL remain insufficiently understood. This study examined the interrelationships between nutrition KAP, lifestyle-related behaviours, body composition, and HRQoL among children from urban-poor flats using serial mediation analysis.

Methods

A cross-sectional study was conducted using cluster sampling to recruit eligible participants from ten urban-poor flats in Kuala Lumpur, Malaysia. Participants completed a sociodemographic questionnaire, nutrition knowledge, attitude, and practice (KAP) questionnaire, Eating Behaviours Questionnaire (EBQ), Physical Activity Questionnaire for Older Children (PAQ-C), and Pediatric Quality of Life Inventory™ (PedsQL™) 4.0. The body composition of the children was also measured using InBody 270s bioelectrical impedance analysis. Serial mediation analysis was conducted through path analysis to evaluate the inter-relationships between variables.

Results

A total of 408 children (mean age = 9.7 years) were recruited. Nutrition attitude significantly mediated the relationship between nutrition knowledge and nutrition practice (b = 0.034, 95% CI: 0.019, 0.054). Nutrition knowledge showed no significant direct effect on HRQoL but demonstrated significant indirect effects through multiple behavioural pathways (p < 0.05), particularly through nutrition attitude, nutrition practice, fast-food intake, supper intake, and physical activity. The final model explained 32.1% of the variance in HRQoL.

Conclusion

These findings suggest that nutrition KAP influences HRQoL primarily through modifiable lifestyle-related behaviours rather than through a direct pathway. Interventions for children in urban-poor communities should therefore combine nutrition knowledge enhancement with strategies that strengthen attitudes, support healthier practices, reduce unhealthy eating behaviours, and promote physical activity.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12955-026-02564-2.

Introduction

Health-related quality of life (HRQoL) is a multidimensional concept that reflects an individual’s perceived physical, emotional, social, and school functioning in relation to health [1]. In Malaysia, rapid urbanisation has contributed to the emergence of urban-poor communities, where children may be exposed to overlapping nutritional and psychosocial vulnerabilities [2]. Previous studies have shown that the prevalence of overweight and obesity among urban-poor children can reach 23.0%, alongside high prevalences of stunting (22.0%) and wasting (20.0%), reflecting the double burden of malnutrition [3]. Children living in poverty are also more vulnerable to psychological distress, including stress and anxiety [4]. Social disadvantages such as stigma, discrimination, and difficulty establishing positive peer relationships may further compromise psychological functioning and HRQoL [5]. In addition, limited access to healthcare, unhealthy food environments, and reduced opportunities for physical activity may further affect children’s overall well-being and HRQoL [6]. Despite these vulnerabilities, most Malaysian studies have focused on the general paediatric population [7–9], with limited research specifically examining HRQoL among children from urban-poor communities.

Nutrition knowledge, attitude, and practice (KAP) play a fundamental role in shaping lifestyle-related behaviours, which may subsequently influence children’s nutritional status and overall health [10–12]. According to the Knowledge-Attitude-Behaviour (KAB) theory, knowledge provides the basis for developing positive attitudes, which in turn influence healthier practices [13]. However, this pathway is not always straightforward in paediatric populations because children often have limited authority over food choices. Children’s dietary practices and physical activity are frequently influenced by parental nutrition literacy, household practices, and the home environment [14, 15]. Previous studies among low-income families have reported lower nutrition knowledge and suboptimal dietary practices among parents [16], which may indirectly influence children’s lifestyle behaviours and health outcomes. Nevertheless, examining children’s own nutrition KAP and lifestyle-related behaviours remains important for understanding the behavioural pathways linking nutrition knowledge and HRQoL. These challenges may be more prominent among children from urban-poor settings, where food insecurity and financial constraints may further hinder healthy lifestyle practices [17].

Lifestyle-related factors may help explain how nutrition knowledge influences HRQoL. A previous study suggested that dietary behaviours and physical activity may mediate the relationship between health literacy and HRQoL [18]. Existing evidence also suggests that children with better nutrition-related knowledge and attitudes are more likely to engage in healthier dietary behaviours and higher physical activity levels [19–23]. In turn, healthier lifestyle behaviours may contribute to more favourable body composition and better HRQoL [24–28]. Moreover, previous findings showed that although nutrition knowledge was associated with HRQoL, the relationship became non-significant after adjustment for lifestyle-related factors [29], suggesting potential mediation effects. However, the specific pathways linking nutrition KAP to HRQoL, particularly among children in socioeconomically disadvantaged settings, remain underexplored.

Therefore, the present study aimed to examine the interrelationships between nutrition KAP and HRQoL by investigating the mediating roles of nutrition attitude, nutrition practice, dietary behaviours, physical activity, and body composition among children living in urban-poor flats in Kuala Lumpur, Malaysia. Understanding these interrelationships may guide the development of context-appropriate interventions to enhance HRQoL in this population.

Methods

Study design

The present study was a cross-sectional study conducted among children recruited through cluster sampling from ten Program Perumahan Rakyat (PPR) flats in Kuala Lumpur, Malaysia. PPR flats are low-cost public housing projects developed to provide affordable housing for low-income citizens in the B40 income group [30]. In Malaysia, households with a monthly income below RM4,850 are classified under the B40 income group [31]. Ten PPR flats were selected using simple random sampling from a list of 27 PPR flats in Kuala Lumpur. Eligible participants were Malaysian children aged 7 to 12 years, without any diagnosed physical or mental disabilities, who were recruited from the selected communities between 2019 and 2020.

The required sample size was calculated using the formula N ≥ 5q, where q represents the number of free parameters in the path model [32]. A total of 52 free parameters were identified in the present study; therefore, a minimum sample size of 260 children was required. After accounting for an estimated 80% response rate and 90% eligibility rate [33], the final adjusted sample size was 362. Ethical approval was obtained from the Ethics Committee for Research Involving Human Subjects, Universiti Putra Malaysia (Reference number: JKEUPM-2019-129), and written informed consent was obtained from both children and their parents before data collection.

Instruments

Sociodemographic information (sex, ethnicity, and age) was collected using self-administered questionnaires. Nutrition KAP were assessed using an adapted questionnaire developed from a previous Malaysian study among adolescents [34]. Prior to data collection, the questionnaire was reviewed by the researchers, pre-tested among 100 urban-poor children, and revised based on feedback from researchers and children to ensure clarity and suitability for the target age group. In the present study, the instrument demonstrated marginal internal consistency, with Cronbach’s alpha values of 0.690, 0.671, and 0.629 for nutrition knowledge (18 items), nutrition attitude (22 items), and nutrition practice (32 items), respectively. The total scores for nutrition KAP were converted into percentage scores, with a maximum score of 100% for each section, and were classified into low (0-33.33%), moderate (33.34–66.66%), and high (66.7–100%) categories [35].

Dietary behaviours were assessed using the Eating Behaviours Questionnaire (EBQ), which examined main meals, snacks, and fast-food intake over the previous seven days [36]. The EBQ was originally developed for Malaysian adolescents and was adapted for use in the present study. As the EBQ assessed distinct dietary behaviours rather than a single latent construct, internal consistency reliability was not evaluated. The questionnaire was pre-tested among children to ensure clarity and comprehension, and trained enumerators provided assistance when necessary.

Physical activity was assessed using the Physical Activity Questionnaire for Older Children (PAQ-C) [37], a 10-item self-administered questionnaire assessing physical activity over the previous seven days. The PAQ-C has been validated and demonstrated acceptable reliability among local Malaysian children [38], and demonstrated marginal internal consistency (Cronbach’s α = 0.620) in the present study. Based on the PAQ-C summary scores, children were classified into three physical activity levels which are low (≤ 2.33), moderate (2.34–3.66), and high (≥ 3.67) [39].

The HRQoL of the children was assessed using the Pediatric Quality of Life Inventory ^TM (PedsQL^™) 4.0 Generic Score Scale [40]. The PedsQL^™ 4.0 has been validated and translated into Malay language and demonstrated acceptable reliability across different ages of children (Cronbach’s α ≥ 0.80) [41], and demonstrated excellent internal consistency (Cronbach’s α = 0.893) in the present study. Children with a HRQoL total score lower than 69.7 were classified as at risk of impaired HRQoL [42].

The body composition of the children was measured through the InBody 270s body composition analyser. The body fat mass and skeletal muscle mass obtained from the instrument were then used to calculate the muscle-to-fat ratio (MFR) by dividing skeletal muscle mass by body fat mass. As there is currently no universally established cut-off value for MFR, higher value MFR values were interpreted as having more favourable body composition.

Data collection was conducted primarily using self-administered questionnaires. However, children aged 7 to 9 years and those who had difficulty understanding the questionnaire were assisted by trained researchers and enumerators, who provided standardised explanations without influencing participants’ responses. Parents or guardians were consulted only when clarification on factual information, such as meal frequency or fast-food intake in the EBQ, was required. No proxy reports were used for the study instruments. Subjective measures, including HRQoL, were answered solely by the children.

Data analysis

Data analyses were conducted using IBM SPSS version 26.0 and IBM SPSS AMOS version 25.0. All questionnaires were checked for completeness and consistency before data entry. Data were entered and cross-checked by the researchers to minimise entry errors. Data cleaning procedures included identifying missing values, verifying outliers, and inspecting data distributions using skewness and kurtosis before analysis. No severe departures from normality were observed, and all variables were retained for path analysis. Descriptive data were presented as numbers and percentages for categorical variables and as means and standard deviations for continuous variables.

Prior to conducting the pathway analysis, simple linear mediation and multiple linear regression (MLR) tests were conducted to identify predictors of HRQoL in the previous study [29]. Factors identified from the MLR model were then included in the present pathway analysis using AMOS version 25.0 to examine the mediating effects of lifestyle-related factors on the relationship between nutrition knowledge and HRQoL. All hypothesised mediators were included in the tested model simultaneously, as shown in Fig. 1, to improve model parsimony and reduce parameter bias due to omitted variables [43]. Mediation effects were assessed using bootstrapped indirect estimates. Significant indirect effects may occur even when one or more constituent direct paths are non-significant. Statistical significance was set at p < 0.05.

Fig. 1.

Conceptual mediation model of lifestyle-related factors between nutrition knowledge and HRQoL

Results

Descriptive findings for sociodemographic factors, lifestyle-related factors, and HRQoL are presented in Table 1. A total of 408 children aged 7–12 years participated in the study (mean age: 9.7 ± 1.5 years), and the majority were Malay (98.8%). Overall, most children demonstrated moderate levels of nutrition knowledge, nutrition practice, and physical activity, while most had high nutrition attitude scores and were at risk of impaired HRQoL.

Table 1.

Socio-demographic factors, lifestyle-related factors, and HRQoL of children from urban-poor flats (N = 408)

Factors	n (%) / Mean ± SD
Age (years)	9.7 ± 1.5
Ethnicity	-
Malay	403 (98.8)
Non-Malay	5 (1.2)
Nutrition knowledge (%)	44.7 ± 18.8
Low	120 (29.4)
Moderate	202 (49.5)
High	86 (21.1)
Nutrition attitude (%)	72.6 ± 8.3
Moderate	86 (21.1)
High	322 (78.9)
Nutrition practice (%)	65.0 ± 7.4
Moderate	214 (52.5)
High	194 (47.5)
Breakfast intake (days/week)	3.8 ± 2.5
Lunch intake (days/week)	4.0 ± 2.3
Dinner intake (days/week)	4.2 ± 2.3
Morning tea intake(days/week)	3.6 ± 2.2
Afternoon tea intake (days/week)	3.7 ± 2.2
Supper intake (days/week)	2.5 ± 2.3
Fast-food intake (days/week)	4.4 ± 3.6
Physical activity	2.98 ± 0.60
Low	56 (13.7)
Moderate	300 (73.5)
High	52 (12.8)
Body fat mass (kg)	7.6 ± 6.6
Skeletal muscle mass (kg)	11.0 ± 3.4
Muscle-to-fat ratio (MFR)	2.28 ± 1.15
HRQoL total score (%)	65.0 ± 18.5
At risk for impaired HRQOL	238 (58.3)
Normal	170 (41.7)

Fitness of the path model

Before proceeding to pathway analysis, multicollinearity between variables was tested, as shown in Table 2. The variance inflation factor (VIF) ranged from 1.05 to 1.23, which did not exceed the standard threshold of 10, while tolerance values ranged from 0.81 to 0.96, which were above 0.10. These findings indicated no evidence of multicollinearity between variables. For the hypothesised pathway model shown in Fig. 1, the model fit indices indicated acceptable fit (χ²/df = 0.931, p = 0.54, GFI = 0.99, NFI = 0.96, CFI = 1.00, TLI = 1.01, RMSEA < 0.001, SRMR = 0.026).

Table 2.

Multicollinearity test among variables associated with HRQoL

Factors	Tolerance	VIF
Nutrition knowledge	0.870	1.149
Nutrition attitude	0.826	1.211
Nutrition practice	0.817	1.225
Lunch intake	0.974	1.027
Supper intake	0.874	1.144
Fast-food intake	0.878	1.139
Physical activity	0.945	1.058
MFR	0.984	1.017

VIF: Variance inflation factor

Direct, indirect, and total effects

The results of the full pathway analysis, including direct, indirect, and total effects, are presented in Supplementary Table S1, which includes all tested paths regardless of endogenous variables. Table 3 summarises the effects of the independent variables on HRQoL. Nutrition attitude, nutrition practice, lunch intake, physical activity, and MFR had significant positive direct effects on HRQoL, whereas supper intake and fast-food intake had significant negative direct effects. Nutrition knowledge was not directly associated with HRQoL but demonstrated significant indirect and total effects, suggesting that its influence on HRQoL operated primarily through mediating pathways.

Table 3.

Total, direct, and indirect effects of nutrition KAP and lifestyle-related factors on HRQoL

Endogenous variables	Predicting variables	Direct effect			Indirect effect (summative)			Total effect			SMC
		b	95% CI	β	b	95% CI	β	b	95% CI	β
HRQoL	Nutrition knowledge	0.046	-0.028, 0.119	0.051	0.158**	0.109, 0.210	0.176	0.204**	0.122, 0.290	0.226	0.321
	Nutrition attitude	0.215*	0.069, 0.362	0.116	0.109	0.000, 0.226	0.059	0.323**	0.156, 0.497	0.175
	Nutrition practice	0.340**	0.138, 0.539	0.155	0.104	-0.006, 0.217	0.047	0.444**	0.213, 0.661	0.202
	Lunch intake	1.341**	0.642, 2.065	0.165	0.040	-0.102, 0.220	0.005	1.382**	0.680, 2.086	0.170
	Supper intake	-1.350**	-2.012, -0.668	-0.171	0.069	-0.056, 0.233	0.009	-1.281**	-1.938, -0.572	-0.163
	Fast-food intake	-1.605**	-2.078, -1.153	-0.316	-0.024	-0.120, 0.059	-0.005	-1.629**	-2.110, -1.187	-0.320
	Physical activity level	3.796**	1.119, 6.400	0.123	0.307*	0.047, 0.842	0.010	4.103**	1.437, 6.576	0.133
	Muscle-to-fat ratio	1.546*	0.278, 2.771	0.097	-	-	-	1.546*	0.278, 2.771	0.097

b: unstandardized coefficients, CI: confidence interval, β: standardized coefficients, SMC: squared multiple correlations

*p < 0.05, **p < 0.01

Among the independent variables, nutrition knowledge and physical activity demonstrated significant indirect effects on HRQoL. Lunch intake showed a significant positive direct association with HRQoL but was not involved in any significant indirect pathway linking nutrition knowledge and HRQoL, indicating its role as an independent predictor rather than a mediator. Overall, the pathway model explained 32.1% of the variance in HRQoL.

Mediating effects

The mediating effects of nutrition attitude, nutrition practice, supper intake, fast-food intake, physical activity, and muscle-to-fat ratio on the relationship between nutrition knowledge and HRQoL were tested through serial multiple mediation analysis. The indirect effects on HRQoL from Table 3 were summative, while the statistically significant individual indirect pathways are shown in Table 4. Results of the full pathway analysis of indirect pathways- are shown in Supplementary Table S2, which includes all tested paths regardless of statistical significance. The overall mediating pathways are illustrated in Fig. 2.

Table 4.

Significant individual indirect pathways linking nutrition knowledge to HRQoL

Paths	b	95% CI	p
via nutrition attitude → HRQoL	0.025	0.011, 0.045	0.003
via nutrition practice → HRQoL	0.013	0.003, 0.029	0.023
via fast-food intake → HRQoL	0.060	0.036, 0.089	0.001
via physical activity → HRQoL	0.018	0.006, 0.037	0.003
via nutrition attitude → nutrition practice → HRQoL	0.012	0.005, 0.022	0.001
via nutrition attitude → nutrition practice → supper intake → HRQoL	0.003	0.001, 0.005	< 0.001
via nutrition practice → supper intake → HRQoL	0.003	0.001, 0.007	0.018
via nutrition practice → fast-food intake → physical activity → MFR → HRQoL	< 0.001	< 0.001, < 0.001	0.046
via physical activity → MFR → HRQoL	0.001	< 0.001, 0.004	0.017

b: unstandardized coefficients, CI: Confidence Interval

Values < 0.001 are displayed as < 0.001. Only statistically significant individual indirect effects are shown

Fig. 2.

Final path model showing significant pathways between nutrition knowledge, lifestyle-related factors, and HRQoL

Findings revealed that nutrition knowledge influenced HRQoL indirectly through nutrition attitude, nutrition practice, fast-food intake, and physical activity. Several serial mediation pathways were also identified, particularly those involving nutrition attitude and nutrition practice, as well as pathways incorporating supper intake and muscle-to-fat ratio. The key indirect pathways were nutrition knowledge → nutrition attitude → nutrition practice → HRQoL and nutrition knowledge → nutrition attitude → nutrition practice → supper intake → HRQoL, indicating that improvements in nutrition-related attitudes and practices may be important mechanisms linking nutrition knowledge to better HRQoL.

Discussion

The present study examined the pathways linking nutrition KAP, lifestyle-related factors, and HRQoL among children from urban-poor flats. Using a mediation model based on KAB theory, the findings suggest that nutrition knowledge influences HRQoL primarily through indirect pathways involving nutrition attitude, nutrition practice, dietary behaviours, physical activity, and body composition. While nutrition knowledge did not have a direct effect on HRQoL, it significantly influenced HRQoL through multiple behavioural pathways. Among the mediators identified, nutrition attitude and nutrition practice played important roles in translating nutrition knowledge into behavioural changes, whereas lifestyle-related factors such as fast-food intake, supper intake, physical activity, and muscle-to-fat ratio further contributed to HRQoL outcomes.

Previous studies have suggested that nutrition knowledge, attitudes, and practices influence dietary behaviours and overall health outcomes among children. KAB theory proposes that knowledge forms the basis for developing attitudes, which subsequently guide practices [13]. This conceptual pathway aligns with the broader concept of nutrition literacy, which encompasses the cognitive and functional skills required to apply nutrition knowledge in daily life [44]. Improved nutrition-related knowledge has been shown to influence dietary behaviours and reduce the burden of nutrition-related diseases [45]. In addition, lifestyle-related factors, including dietary behaviours and physical activity, have been reported to influence HRQoL [24–28]. A previous study also suggested that lifestyle behaviours may mediate the relationship between health literacy and HRQoL [18]. However, the specific mechanisms linking nutrition knowledge and HRQoL among children, particularly those living in socioeconomically disadvantaged communities, remain underexplored.

The present study extends existing literature by demonstrating that nutrition knowledge may influence HRQoL primarily through behavioural pathways rather than through direct perception of health. Previous studies have reported that improvements in health-related knowledge, attitude, and practice may reduce the human and economic burden of disease [45]. As HRQoL reflects subjective perceptions of physical, emotional, and social functioning, children with healthier behaviours and better health status may perceive better HRQoL [46, 47]. While nutrition knowledge did not directly influence HRQoL in the present study, its indirect effect through nutrition attitude and practice supports the hypothesis that knowledge affects HRQoL primarily through behavioural pathways rather than perception alone [18].

Beyond the basic KAB framework, the inclusion of lifestyle-related factors further explained the mechanisms linking knowledge and HRQoL. Consistent with previous studies, nutrition knowledge was associated with fast-food intake and snack intake [23], which in turn influenced HRQoL [24, 28]. However, nutrition attitude was not directly associated with supper or fast-food intake. This may reflect contextual challenges faced by children living in urban-poor communities, where food choices are often constrained by household resources, food availability, and affordability [48]. In Malaysia, fast food and energy-dense street foods are highly accessible and relatively affordable, while late-night eating has become increasingly common due to the widespread availability of 24-hour eateries [49, 50]. Consequently, although children may have positive nutrition attitudes, environmental and financial constraints may reduce their ability to consistently practise healthy eating behaviours. In addition, children’s self-regulation skills are still developing, which may hinder the translation of positive attitudes into consistent healthy eating behaviours [51, 52]. This challenge may be further influenced by exposure to food marketing and advertisements, which can affect children’s food preferences regardless of their existing attitudes towards healthy eating [53].

Nevertheless, the present findings suggest that nutrition knowledge may indirectly influence dietary behaviours despite these contextual challenges. Although the association between nutrition knowledge and dietary behaviours can be constrained by competing influences such as taste preferences, affordability, and food availability [54, 55], the present findings indicate that nutrition knowledge may support children in considering healthier options when opportunities for independent food decisions arise [56]. In a resource-constrained setting, nutrition knowledge may therefore support children in making relatively healthier choices, although it may not fully overcome environmental and financial barriers [57]. This suggests that nutrition knowledge should be viewed as a supporting factor operating within broader food and household environments rather than as an independent determinant of dietary behaviour. Overall, these findings highlight its potential indirect contribution to dietary behaviours, which may in turn be associated with HRQoL among children from urban-poor communities.

The negative associations of fast-food and supper intake with HRQoL may be explained through multiple health-related mechanisms. In the Malaysian context, fast-food intake and late-night eating practices have become increasingly common among children and adolescents, with 24.7% and 41.8%, respectively, engaging in these behaviours at least once per week [58]. Frequent fast-food intake, which is typically high in fat, sodium, and refined carbohydrates, has been associated with obesity, poorer physical health, and reduced psychosocial well-being among children [24, 28]. Similarly, frequent supper intake may contribute to digestive discomfort, excess weight gain, and poorer sleep quality [59, 60], all of which may negatively influence children’s physical and emotional functioning [61]. Therefore, lower fast-food and supper intake may contribute to better HRQoL through improved physical health, body composition, sleep quality, daily functioning, and psychosocial well-being [26, 62, 63]. These mechanisms may partially explain the mediating roles of fast-food and supper intake observed in the present study.

Physical activity significantly mediated the relationship between nutrition knowledge and HRQoL, both directly and indirectly through MFR. Children with higher nutrition knowledge may have better health awareness, which could support higher physical activity and better HRQoL. In turn, physical activity may improve body composition by reducing fat mass [64, 65], which is associated with better HRQoL [66, 67]. This finding aligns with previous research showing that body composition mediated the relationship between physical activity and HRQoL, although earlier studies primarily relied on BMI [68]. The lack of a direct effect between nutrition knowledge and MFR may reflect developmental factors, as body composition in prepubescent children is strongly influenced by growth and pubertal timing [69]. Overall, the present study highlights several modifiable behavioural pathways linking nutrition knowledge and HRQoL. These findings provide useful insights for designing intervention strategies aimed at improving children’s HRQoL, particularly within socioeconomically disadvantaged communities.

Strengths and limitations

This study is among the first to examine the indirect pathways from nutrition KAP to HRQoL while incorporating multiple behavioural and physiological mediators. The use of a robust pathway analysis framework enabled us to identify specific mediators such as nutrition attitude and physical activity, which can be targeted for future intervention development. In addition, the focus on children from urban-poor flats addresses a critical gap in public health research, as this underrepresented population often faces vulnerabilities, including socioeconomic disadvantage, limited access to healthy food, and environmental barriers to physical activity, which are often overlooked.

The present study has several limitations that should be acknowledged. First, this was a cross-sectional study and therefore could not establish causal relationships. While the mediation model suggests possible pathways through which nutrition KAP may influence HRQoL via lifestyle-related factors, causality cannot be inferred from observational data. A cohort study is needed to assess the long-term outcomes of these relationships. In addition, the present study focused on children living in urban-poor flats in the central region of Malaysia, with almost all participants being Malay (98.8%). Although ethnicity was not a primary focus of the present study, the ethnic homogeneity of the sample may limit the generalisability of the findings to Malaysia’s multi-ethnic child population, as cultural practices across ethnic groups could influence lifestyle behaviours [70]. Thus, future researchers should be cautious when applying or comparing these findings to more ethnically diverse populations. Although the instruments used in the present study had been validated or adapted for the Malaysian context and showed marginal to good reliability, the use of self-reported questionnaires may still be prone to measurement error and recall bias.

Conclusion

The present study offers new insights into the multifactorial determinants of HRQoL among children living in urban-poor communities, emphasising the complex interrelationships between nutrition KAP, lifestyle-related behaviours, and HRQoL. Using a serial mediation model based on KAB theory, the study found that nutrition knowledge does not directly affect HRQoL but influences it through multiple key mediators, including nutrition attitude, nutrition practice, fast-food intake, supper intake, and physical activity. Notably, the indirect pathways indicate that positive nutrition attitudes need to be reinforced by practical behavioural support to improve children’s dietary patterns and ultimately enhance HRQoL. The present model provides a useful foundation for developing more comprehensive, theory-driven, and community-oriented health promotion strategies. Future research should test interventions based on the present model and explore additional factors, such as parental influence and food environment, to further improve HRQoL among children from urban-poor communities.

Supplementary Information

Below is the link to the electronic supplementary material.

Abbreviations

HRQoL

Health-related quality of life

KAP

Knowledge, attitude, and practice

KAB

Knowledge-attitude-behaviour

PPR

Program Perumahan Rakyat

MLR

Multiple linear regression

MFR

Muscle-to-fat ratio

VIF

Variance inflation factor

GFI

Goodness-of-fit index

NFI

Normed fit index

CFI

Comparative fit index

TLI

Tucker–Lewis index

RMSEA

Root mean square error of approximation

SRMR

Standardized root mean square residual

b

Unstandardized coefficient

CI

Confidence interval

β

Standardized coefficients

SE

Standard Error

SMC

Squared multiple correlations

Author contributions

JMHC and YSC conceptualized the study. Literature searches and data collection were primarily conducted by JMHC and YSC. All authors (JMHC, YSC, HAS, PYL, YMC, and ZMS) contributed to the interpretation of data. JMHC and YSC wrote the original draft of the manuscript and all authors revised and approved the final manuscript for submission.

Funding

The present research was supported by World Vision Malaysia (grant number 6380028) and Universiti Putra Malaysia under GP-IPS (grant number 9691800).

Data availability

The dataset analysed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

The study was approved by Ethical Committee for Research Involving Human Subjects Universiti Putra Malaysia (JKEUPM-2019-129), and was conducted in accordance with the principles of the Declaration of Helsinki. Written consent was obtained from all participating children and their parents.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.