Association between nutritional status and cognitive function scores of adolescent girls in underprivileged communities

Introduction

It is well established that high quality of human resources (HR), as a crucial indicator of a country’s progress and development, is strongly associated with the cognitive performance status of individuals [1], [2], [3]. In the recent report from the World Population Review, in 2022, it was reported that the average cognitive level of children in Indonesia was 78.5, which ranks Indonesia 130th out of 199 countries [4]. This figure is lower than neighboring countries such as Laos (81.0), the Philippines (81.6), Brunei Darussalam and Malaysia (87.6), Thailand (88.9), Vietnam (89.5), and Myanmar (91.2) [5], 6].

In addition, the main underlying causes associated with low human resources are often linked to low cognition status, which is significantly attributed to low educational quality, lack of literacy, early marriage, as well as poor nutritional and health status such as CED, stunting, nutritional deficiency anaemia, and poor and unhealthy diet practices. All of these underlying contributing factors are significantly associated with low cognitive performance among growing populations such as children and adolescents [7], 8].

Based on the Basic Health Research report in 2018, it was reported that the prevalence of CED among adolescent girls had reached 23.6 %, and not much improvement was found in the recent Indonesian Health Survey (IHS) of 21.4 %, with only a slight reduction of 2.2 % over 5 years [9]. Stunting, as manifested as short stature, remains an important undernutrition problem affecting about 30.8 % of Indonesian children and adolescents [10]. Moreover, nutritional anaemia is another serious nutritional disorder in adolescent girls in Indonesia, with a higher prevalence of 24.1 % based on the recent nationwide IHS survey conducted in 2023 [11], which is a similar observation reported in the previous Basic Health Research report (26.4 %) in 2018 [12], 13]. These three nutritional conditions are interrelated and exacerbate each other, creating a chain cycle that is difficult to break [14], [15], [16].

Adolescent girls are a very important population group to study because they are in a developmental phase that determines the quality of health and nutritional well-being in adulthood, including readiness to become mothers in the future. CED, anaemia, and stunting are interrelated nutritional problems that could significantly impact both physical and cognitive performance and development [17], 18]. CED reflects long-term inadequate energy intake, which can lead to metabolic and body function disorders [19]. Anaemia, which is commonly caused by iron deficiency, can reduce the ability to transport oxygen in the blood, affect concentration, and decrease learning capacity [18], 20], 21]. In addition, stunting is not only associated with poor height attainment, but it also significantly affects brain development, resulting in limited intellectual and cognitive performance and functions [22], 23].

The Indonesian government has implemented various efforts to address nutrition problems in adolescents, one of which is the school-based Nutrition Action Program, which includes the iron-folate supplementation (IFA) Program, with the main focus on preventing and treating anaemia in adolescent girls [24], 25]. However, challenges in implementation remain, including low compliance, limited awareness, and logistical barriers [26], 27].

The nutritional problems in adolescent girls found at the national level were also reported in several regions such as Takalar District, in South Sulawesi. For example, the prevalence of CED among non-pregnant women of reproductive age was 20.28 % in 2018. In addition, the prevalence of anaemia among adolescent girls in Takalar increased from 13.4 % in 2019 to 18.5 % in 2023, suggesting an upward trend. A similar observation was found for undernutrition and stunting, where the prevalence among adolescent girls aged 13–15 years in South Galesong District was 23.5 % [28]. In Takalar Regency, South Sulawesi – an underprivileged area with high levels of poverty and limited access to nutritious food – these problems are especially prominent. The prevalence of CED in women of reproductive age was 20.3 % in 2018, while anaemia among adolescent girls increased from 13.4 % in 2019 to 18.5 % in 2023. In South Galesong District, stunting affected 23.5 % of girls aged 13 to 15 [28], 29].

Therefore, this study was formulated to assess the prevalence of nutritional problems, particularly the risk of CED, anaemia, and stunting problems, as well as to determine the relationship between these assessed nutritional statuses and cognitive function status among adolescent girls in Takalar Regency, South Sulawesi Province. It is hoped that the present findings of the study could be used to formulate more effective and tailored, evidence-based nutritional and health interventions, specifically targeted at adolescent girls from underprivileged communities.

Methods

This study is part of a larger true experimental research project on nutritional interventions among adolescent girls. However, this article focuses solely on the baseline data collected through a cross-sectional survey. The study was conducted between July and November 2024 in two public schools located in Galesong Selatan, Takalar Regency: SMAN 13 Takalar and SMPN 3 Galesong Selatan. These schools were selected as they represent key educational centers for adolescent girls in the area, which comprises approximately 500 students with limited access to higher education.

The study included 372 adolescent girls aged 11–17 years enrolled in the first or second year of junior or senior high school. Inclusion criteria included age (11–17 years), enrollment in selected schools, and willingness to participate with parental consent. Exclusion criteria included girls with severe malnutrition, anaemia, or other medical conditions as identified through school health records or self-report validated by medical staff.

Sampling was conducted using a simple random method after obtaining approval from school authorities and informed consent from both students and their parents or guardians. Data collection involved, structured questionnaires to obtain demographic, socioeconomic, and health information. Anthropometric measurements, including height, weight, and MUAC, taken using standardized equipment and protocols by trained enumerators. Dietary intake assessment using 24-h dietary recall interviews, analyzed for energy and nutrient adequacy. Cognitive function assessment using the Culture Fair Intelligence Test (CFIT), administered by licensed psychologists from Universitas Hasanuddin. CFIT was chosen for its low cultural bias and established reliability in assessing non-verbal intelligence.

Data analysis was performed using SPSS version 25. Descriptive statistics were used to present demographic and nutritional status. Bivariate comparisons were conducted using t-tests and chi-square tests. Multivariate linear regression was employed to identify independent predictors of cognitive function, controlling for age, socioeconomic status, school, and dietary energy intake. Statistical significance was set at p<0.05.

This study was approved by the Health Research Ethics Committee, Faculty of Public Health, Universitas Hasanuddin (Ethical Approval No. 2739/UN4.14.1/TP.01.02/2024, dated September 30, 2024). The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). Written informed consent was obtained from both participants and their legal guardians prior to data collection. This study has also been registered on ClinicalTrials.gov with the identifier NCT07037498, as listed on the official website of the National Institutes of Health (NIH), one of the world’s foremost medical research centers and an agency of the U.S. Department of Health and Human Services.

Results

A total of 372 adolescents participated in the study based on first- and second-year students, were these participants represented a diverse demographic, with the majority attending senior high schools (SMA) and most falling in the 11–17-year age range (Table 1). Almost half of their parents had attained highest education levels of at least senior high school levels, almost similar pattern was found between father and mother education levels. In terms of occupational status, majority of their mothers were housewives, while fathers were largely employed in farming or self-employment. The monthly family household income was around the IDR 500.000–1.000.000 range.

Table 2 shows the nutritional and health status of the respondents, as well as the intake of iron-folic acid (IFA) supplementation among these participants. Based on the anthropometric, almost half of these girls were classified as underweight (49.7 %), while only one-third were at normal BMI based on their age (37.6 %). When assessment for each nutritional status indicators such as stunting and wasting was carried-out, it found that the prevalence of stunting as assessed by low height-for-age (H/A) was 18 %, while wasting problem as derived by low BMI-for-age (BMI/A) was 11.3 %.

The present analysis found the differences in the chronic energy deficiency (CED) prevalence, which affected 19.9 % of respondents, and premenstrual syndrome (PMS) status, with 62.1 % reporting PMS symptoms. For the IFA supplementation status, about 46.5 % of these participants had reported to receive IFA tablets. Out of these participants (n=173), only 28.5 % had consumed at least one tablet weekly, as recommended. In contrast, majority of these girls (69.9 %) had not taken IFA at all. These findings highlight critical areas of nutritional deficiencies and limited compliance with IFA supplementation that warrant targeted intervention programs.

Table 3 shows the mean intakes of energy, protein, fat, carbohydrates, vitamin C, and iron, and nutrient adequacy based on daily recommended nutrient intake. Majority of these participants failed to meet the recommended daily intake for macronutrients such as energy (94.1 %), carbohydrates (96.0 %), Fat (82.5 %) and protein (86.0 %), and other micronutrients such as Vitamin C (95.7 %) and iron (94.5 %). These suggest that they were unable to achieve the recommended daily intakes for most essential nutrients in their daily dietary intake. These findings indicate a widespread issue of poor dietary quality, suggesting potential risks for malnutrition and associated health problems. The data underscores the urgent need for targeted interventions to improve nutrient intake in this population.

A significant relationship between nutritional status and cognitive scores of these present adolescents was also reported. Based on the mid-upper arm circumference (MUAC) assessment, girls with normal nutritional status had a higher average cognitive score (78.8) compared to the group with Chronic Energy Deficiency (CED), which had an average score of 74.3. Similarly, in the measurement of height-for-age (z-scores), the group with normal height had a higher average cognitive score levels, compared to the stunted participants (78.9 vs. 73.2). These findings suggest that poor nutritional status was signicantly associated with poor cognitive function and development in adolescents. Hence, it highlights the importance of improving nutritional status through appropriate interventions is particularly crucial to be implemented in order to reduce the risk of poor and low cognitive function and development among these adolescent girls during these critical years of growth (Figure 1).

Figure 1:

Mean cognitive scores according to MUAC category (A) and height-for-age category (B). Significant differences were observed between categories for both variables (p < 0.05).

A multivariate linear regression model analysis was used to explore the relationships between nutritional status assessed, and cognitive function scores, by taking into account other potential known confounding factors such as age, socioeconomic status, and dietary intake.

Table 4 shows the results of a multivariate regression analysis controlling for confounders (age, dietary intake, socioeconomic status, and school). The BMI-for-age z-score (β=3.419, p<0.01), height-for-age z-score (β=0.652, p<0.01), and IFA use (β=4.054, p<0.05) were significant predictors of cognitive scores.

Discussion

This study showed that the prevalence of chronic energy deficiency (CED) (19.9 %) and stunting (18.0 %) among adolescent girls in Takalar Regency was accompanied by inadequate intake of both macro- and micronutrients. These nutritional deficiencies not only impair physical growth during adolescence but may also compromise cognitive function during critical academic years. Cognitive performance was assessed using the Culture Fair Intelligence Test (CFIT), which minimizes cultural and educational bias, making it suitable for the study population. Girls with normal nutritional status – determined by MUAC and height-for-age z-scores – had significantly higher cognitive scores, as did those who consistently consumed iron and folic acid (IFA) supplements. These findings support existing evidence linking adequate nutrition to better cognitive outcomes [30], [31], [32].

Significantly, junior high school students showed a greater proportion of “Average and above” and “Intelligent” cognitive categories compared to senior high school students. This pattern, combined with the significant association between IFA intake and anthropometric indicators (MUAC and height-for-age) with cognitive performance, reaffirms the critical role of nutrition in adolescent cognitive development. Nevertheless, the use of CFIT, while beneficial in reducing bias, may limit direct comparison with other tools like Raven’s Progressive Matrices (RPM) or the Wechsler Intelligence Scale for Children (WISC), which are commonly used internationally [31].

The novelty of this study lies in its localized perspective. While previous research has consistently demonstrated the relationship between nutrition and cognitive performance, the current findings highlight how this relationship is compounded in Takalar by broader socioeconomic factors. High rates of CED, stunting, and anaemia intersect with poverty and limited access to nutritious food, healthcare, and quality education. These social determinants significantly shape the nutritional environment and cognitive development opportunities of adolescents. Therefore, addressing adolescent cognitive outcomes requires integrated interventions that target both nutritional deficits and structural inequalities.

International comparisons further underscore this disparity. Studies utilizing RPM or WISC in developed countries report average IQ scores between 100 and 115 – significantly higher than the scores observed in Takalar [31]. These differences are influenced by external factors such as education quality and socioeconomic status. In countries with better school infrastructure and consistent access to healthy diets, children exhibit higher cognitive performance. In contrast, the low intake of essential nutrients in Takalar, often due to habits like skipping breakfast, long school hours, and reliance on nutrient-poor snacks, contributes to suboptimal brain development and poor test performance [33], [34], [35], [36], [37], [38], [39].

This study found that the majority of adolescent girls had nutrient intakes below 80 % of the recommended dietary allowance (RDA), which affects their ability to attain optimal cognitive function [33], [34], [35]. Poor dietary habits and time constraints lead many to miss proper meals, resulting in insufficient energy and micronutrient intake. As a result, adolescents with CED, anaemia, and stunting demonstrated lower cognitive scores than their well-nourished peers [40].

International evidence aligns with these observations. Prado et al. (2017) in South Africa reported that iron deficiency and anaemia can reduce problem-solving and memory abilities by up to 15 % [41]. In Kenya, children at risk of stunting were shown to have significantly lower cognitive scores than children with normal growth trajectories [42], 43]. In the United States, where nutritional problems are less prevalent, even minor deficiencies – such as in vitamin D – have been linked to cognitive delays [44], 45]. This illustrates how even mild nutritional insufficiencies can impact cognitive development, particularly in environments already limited in educational and developmental support.

Similar findings have been documented in Indonesia. Widyastuti et al. (2020) in Yogyakarta found that adolescents with anaemia had double the risk of low cognitive scores compared to their non-anaemic peers [46]. In Lombok, Wibowo et al. (2018) observed a strong link between adequate nutritional status and academic achievement [47]. However, the nutritional landscape in Takalar differs from these regions. The frequency of meal skipping and lower intake of nutritious food remains more pronounced, highlighting the need for targeted nutrition interventions tailored to the specific challenges of coastal and rural communities like Takalar.

The differences between research findings in Takalar and those in other studies, both domestic and international, can be attributed to several factors. Socioeconomic conditions are a major cause. In Takalar, most families fall into the lower-middle economic category, limiting access to nutritious food and healthcare services. Parents’ education levels also play a role, with the majority having only secondary education, resulting in a low understanding of the importance of a healthy diet. Another significant factor is culture and eating habits, where snacks like fried foods or sugary drinks are preferred over nutritious meals.

This study has some limitations that are more technical in nature and could be an opportunity for future development. One limitation is the focus on the relationship between nutritional status and cognitive function, while other variables such as learning environment, stress levels, sleep patterns, or psychosocial factors have not been explored in depth. In addition, the limited scope of the study to two schools in Takalar District provides a specific picture that is highly relevant to the local context, but opens up opportunities to expand the study to other regions with different socioeconomic and cultural characteristics. Nonetheless, the findings of this study have high validity and make an important contribution as a basis for broader and more targeted nutrition interventions, particularly to support the cognitive development of adolescent girls in Indonesia.

The findings of the present study underscore the urgency and need for holistic and effective interventions to improve the nutritional status of adolescent girls in Takalar. More proactive community- and/or school-based efforts in nutrition education, increased distribution of IFA, and improvements in the learning environment are strategic steps that must be implemented. Furthermore, more integrated programs involving families, schools, and local governments can help create sustainable change. It is hoped that this research will not only serve as a scientific foundation for better nutrition policies but also as an important nutritional intervention strategy that could help to improve the quality of human resources in the future, enabling children and adolescents from the underprivileged communities to compete at national and global levels.

Conclusions

The main findings of the present study indicate poor nutritional status had significantly impact on low cognitive function scores in adolescent girls in Takalar Regency, in which participants with normal nutritional status, had significantly higher cognitive scores than that of adolescent girls with stunting or CED risk. Moreover, regular consumption of iron-folate supplements of at One tablet in a week also significantly higher cognitive score. These findings highlight the importance of effective nutritional interventions to enhance and improve cognitive function development in adolescent girls of underprivileged communities, that are particularly susceptible to the challenges of malnutrition.