Child malnutrition is a global public health problem with consequences for children’s physical, psychological, and social development (1). In the context of migration, this challenge becomes even more complex, as migrant children often face social, economic, cultural, and access barriers to health and nutrition throughout the entire migration journey, making them particularly vulnerable (2). These conditions of social vulnerability make them more prone to food insecurity, malnutrition, and disruptions in eating practices (3). In addition, migrant children face greater disadvantages in health, psychosocial risk, exclusion from the school system, and multidimensional poverty compared to native children, especially when they live in unsafe or precarious conditions (4). In particular, the intersection between structural food insecurity, and sociocultural adaptation emerges as a complex issue that affects migrant childhood and has been little explored in the Chilean context (5–7). However, this reality is increasingly present in the countries of the Southern Cone and in their migratory flows, where structural conditions of inequality and social exclusion are intertwined with mobility processes and deepen the gaps in child health and nutrition (2). Thus, understanding these interrelated dynamics is essential for addressing the structural and cultural determinants in Chile that influence migrant children’s nutritional well-being and for guiding actions that uphold their right to food and health.

Child nutritional health mirrors broader social inequalities, which often restrict children’s access to adequate food—both in terms of quality, quantity, and regularity, thereby contributing to what is known as food and nutritional insecurity (FNI) (8). As highlighted by the Food and Agriculture Organization (9), this condition disproportionately affects children, women, and other vulnerable groups, with migrant children being particularly impacted (3, 10).

FNI manifests in various ways, ranging from overt hunger to nutrient-poor diets and, paradoxically, even overweight and obesity, conditions that can coexist within the same community or household (3). To understand FNI, it is essential first to consider its counterpart—food and nutritional security (FNS)—which is defined as the sustainable guarantee of access to sufficient, safe, nutritious, and culturally appropriate food (9). FNS is a multidimensional concept that extends beyond the mere absence of hunger or the availability of food; it encompasses stability, quality, and cultural adequacy of diet—dimensions that are particularly relevant in migratory contexts. Migration itself constitutes a social determinant of health (11), influencing each of these dimensions. Ensuring FNS, therefore, requires guaranteeing regular access to adequate and nutritious food while respecting the cultural identities and food practices of diverse groups (7, 12). However, constrained access to adequate food and nutrition often characterizes the entire migration journey, since the structural conditions that weaken FNS are frequently present even before migration.

In many countries of origin, children already face FNI, one of the main factors driving families to migrate to other Latin American countries, where limited food variety and insufficient availability continue to pose challenges (13–16). For example, a study of Venezuelan migrant families in Colombia revealed that widespread food and nutritional insecurity in their home country was a key driver of migration, as many families faced severe difficulties in obtaining sufficient and nutritious food (10). Participants described how the combined effects of economic collapse, political instability, and frequent shortages left them unable to feed their children adequately. Migration thus emerged as a survival strategy to restore access to food. In Guatemala, one of the countries with the poorest progress in reducing child malnutrition in the region, research indicates that international migration, particularly by fathers, can function as a strategy to alleviate children’s FNI through the income provided by remittances. However, the same study found that in households where fathers had migrated within the previous year, children under three years of age faced a higher risk of growth delays. Although remittances constitute a vital source of household income, they do not fully offset the negative consequences of prolonged parental absence during early childhood, a critical period for growth and development (17).

Beyond these dynamics at the origin, the transit stage of migration further exposes children to heightened nutritional risks. In the Peruvian context, Vargas-Machuca et al. (18) conducted a study at the Binational Border Healthcare Center in Tumbes to assess the nutritional status of Venezuelan children under five years of age arriving in the country. The findings revealed that approximately 3% of these children experienced acute malnutrition, while chronic malnutrition affected up to 18%, and anemia was present in one-quarter to one-third of the sample. During the migratory journey, less than one-fifth of children met the minimum recommended meal frequency, and many did not receive adequate solid or semi-solid foods due to the logistical and financial constraints inherent to migration (18).

In host countries, Pico et al. (10) note that while families may experience greater access to food at more affordable prices, serious challenges remain, such as labor precarity, informality, and low household income, which continue to limit access to truly nutritious food. This vulnerability is further exacerbated by language barriers, precarious housing, and the lack of institutional support networks, which hinder integration and the realization of the right to food in host context (19).

In the host country context, a study of migrant and Chilean schoolchildren in Antofagasta during the COVID-19 pandemic found that 73.3% experienced some degree of food and nutritional insecurity (FNI), with similar overall prevalence among nationals and migrants; however, severe FNI was more frequent among migrant students (20). Interestingly, while food security among Chilean families declined as household size increased, the opposite was observed among migrant families, suggesting that family cooperation and support networks play a protective role. This finding is consistent with Vilar-Compte et al. (21), who identified an inverse relationship between FNI and social support, as resource sharing and informal exchange mechanisms within migrant communities may help sustain food availability (21).

Malnutrition includes both undernutrition, which appears as deficiencies in essential nutrients reflected in low weight, stunting, or wasting, and overnutrition, expressed through overweight and obesity (1). The coexistence of these contrasting forms is known as the double burden of malnutrition, which is particularly prevalent in contexts characterized by social inequality and migration (8, 22, 23). This situation reflects the tension between persistent food and nutritional insecurity and the growing exposure to calorie-dense, ultra-processed diets, shaped by precarious living conditions and unequal access to healthy foods (6, 21, 23).

Research from high-income countries shows that migrant children often experience both forms of malnutrition. A systematic review conducted on malnutrition among migrants and refugees found that rates of overweight and obesity range from 11 to 42%, while stunting and underweight vary between 0.3 and 17% (24). Similar findings have been reported among Hispanic children in the United States, who display higher obesity rates together with deficiencies in micronutrients such as vitamin D, iron, folate, and iodine (23). In Mexico, children in households connected to migration or remittances also show an increased risk of overweight and obesity (21). These outcomes are influenced by acculturation processes, which refer to the cultural changes that occur through continuous contact with a new society (25), as well as the expansion of the global food industry (23). Migration alters eating behaviors, as food is a cultural practice deeply embedded in family life and identity (26–28). Adaptation to dominant food cultures can lead to increased consumption of industrialized products and less healthy diets, particularly when migrants transition from low-income to high-income countries (19).

Studies with Hispanic populations in the United States show that lower levels of acculturation are associated with more traditional diets rich in fruits, rice, and beans, whereas higher acculturation corresponds to greater consumption of fast food, sugar, and soft drinks (29, 30). Acculturation also influences family dynamics. Mothers who adopt assimilative parenting strategies tend to develop less healthy eating patterns, while higher parental education is associated with better diet quality (31, 32). In low- and middle-income countries, these dynamics are particularly significant because child undernutrition continues to coexist with rising rates of overweight and obesity (22). Additionally, a comparative study on health and lifestyle among migrant and native children in Chile found that, overall, migrant children showed better physical and nutritional indicators than Chilean children (32). Like other developing countries, Chile has undergone a notable epidemiological transition marked by a decline in infant mortality and malnutrition, among other indicators (33). An important part of this transition is marked by an improvement in the country’s socioeconomic levels, greater excess nutrients and a decrease in physical activity among children. Among the public policies that have guaranteed access to food for children, the establishment of the National School Assistance and Scholarship Board (Junta Nacional de Auxilio Escolar y Becas JUNAEB) stands out. Since 1964, it has provided free meals to all children attending public educational institutions (34, 35). These food programmes have had a significant impact not only on the eradication of child malnutrition, but also on the fight against poverty and the increase in school enrolment in various countries (36). Given this context, and considering the intersection between structural food insecurity, and sociocultural adaptation as a complex issue that affects migrant childhood and remains underexplored in the Chilean context, the aim of this study is to analyze the nutritional status of migrant children and adolescents, identifying both the barriers and enabling factors that influence the effective exercise of their right to adequate access to food and nutritional health through a mixed-methods study.

A mixed-methods design was selected because the nutritional status of migrant children and adolescents is shaped by both quantifiable factors and complex social determinants that cannot be fully understood through a single methodological lens. Quantitative data allow us to assess and compare nutritional outcomes between migrant and non-migrant children and adolescents, providing measurable evidence of inequities in access to food and nutritional health. However, to meaningfully interpret these disparities, it is essential to explore the contextual realities that underlie them. The qualitative component complements and deepens the quantitative findings by capturing caregivers’ lived experiences, including the structural barriers, enabling conditions, and sociocultural influences that affect their ability to exercise their right to adequate nutrition. This convergent integrated approach therefore strengthens the validity and policy relevance of the findings, offering a comprehensive understanding of the coexistence of multiple forms of malnutrition among children and adolescents in Chile, and illustrating disparities in nutrition realities.

The findings combine both components (i.e., quantitative and qualitative) to increase the understanding of the nutritional status of migrant children and adolescents, and to comprehensively identify both the limiting and facilitating factors that influence the effective exercise of their right to access food and health nutrition. The results are organized by three dimensions: (1) nutritional status, food insecurity and its association with conditions of origin and displacement; (2) Food and Nutritional Insecurity (FNI) and barriers accessing healthy food in the context of arrival; and (3) lack of cultural acceptability and relevance in child nutrition programs that emerged mainly from the in-depth interviews, for this reason, the dimension is mainly supported by qualitative data.

This study reveals the coexistence of multiple forms of malnutrition among children and adolescents in Chile illustrating a disparity in nutrition realities faced by migrant children and adolescents. Firstly, the findings show that qualitative and quantitative data are consistent about the existence of food insecurity and undernutrition that affect these groups in context of origin and displacement. From quantitative data migrant children from LAC present a higher prevalence of undernutrition and risk of undernutrition compared with Chilean children, despite having lower rates of overweight and obesity. Qualitative data shows that lack of food can be considered a pull factor to migrate from countries that are living a nutritional crisis as Venezuela (47). These results are consistent with regional evidence from Peru and Colombia, where newly arrived Venezuelan children show elevated levels of wasting and anemia (10, 18). Worryingly undernutrition not only affects children and adolescent, but also pregnant women, condition that can lead maternal complications and long-term health issues for the child (16, 48). Despite evidence of the importance of solidarity networks for coping with food insecurity during transit (49), access to food for children is also not guaranteed during displacement, especially for people migrating through non-authorised crosspoints.

As the study evidence national programs are focused on addressing overweight and obesity (50) among children and adolescents, overlooking a vulnerable subgroup whose right to adequate nutrition remains poorly understood and unmet (51). In fact, Chile has achieved significant progress in controlling undernutrition over past decades through programs such as the National Complementary Feeding Program (PNI) and the school feeding program managed by the Junta Nacional de Auxilio Escolar y Becas (JUNAEB) (34, 35). These interventions have contributed to a steady reduction in childhood stunting and underweight since the 1990s (51, 52). However, the country now faces one of the highest childhood obesity rates globally, with over half of preschool children classified as overweight or obese (53). Consequently, public policies have shifted almost exclusively toward combating overnutrition, leaving little institutional attention to the resurgence of nutritional deficits in specific subpopulations, including migrant children (54).

Secondly, the study shows that food and nutritional insecurity does not disappears in the host country. In Chile, the phenomenon appears to be reinforced by economic vulnerability, spatial segregation and administrative barriers, including migration status, that limit access to child health and school feeding programs (7). The CASEN 2022 data reveal that nearly one in three migrant households with children experiences severe food insecurity, a rate nearly double that of Chilean households. This suggests that migrant families, even those not classified as poor by income, remain disproportionately exposed to food deprivation and instability in comparison to Chilean families (7). Previous evidence (4) had shown the inequalities faced by migrant children in terms of multidimensional poverty and access to health services. The data reported here are consistent with these findings and add the factor of food insecurity, revealing new forms of inequality. Even though poverty, spatial segregation and the lack of basic conditions such as access to drinking water and sanitation affect the food security of children, regardless of whether or not they are migrants, the data show that these factors override administrative barriers such as migration status and the lack of support networks, which are key to ensuring safe and quality food. Otherwise, data reported shows that these disparities are not only economic but also institutional. Our study identified that many migrant families, particularly those in irregular migration status, cannot access public food programs such as JUNAEB due to the lack of a national identification number (RUT) or enrollment in the social registry. Similar barriers have been reported in other Latin American contexts where migrants are excluded from social protection systems (2, 19). The achievements made in controlling malnutrition through school feeding programmes (35) must be extended to emerging vulnerable groups such as migrant children, especially those from countries without food security (55) or those who are in an irregular migratory situation (56). Lack of regular status has been reported as a risk factor not only for pregnancy among migrants, but for different pathologies, especially contexts in which access to healthcare requires significant out-of-pocket expenses. A study comparing the economic outcomes of Latin American migrants in Spain and the United States showed that legal status has a more pronounced effect on undocumented migrants than on documented migrants, especially in the United States (57). In this case, the data show that when immigration status is a barrier to accessing school feeding programmes, it can exacerbate the effects of food insecurity in migrant children.

Thirdly, beyond institutional exclusion, qualitative data highlight that health and nutrition programs in Chile often lack cultural relevance and does not consider the food practices and knowledge of migrant communities. Migrant families reported difficulties in understanding or accepting the dietary guidelines provided by primary health centers, which are designed from a Chilean perspective and do not incorporate the cultural diversity of migrant populations. This echoes findings from Hun et al. (5), who emphasize that dietary acculturation processes can generate tension between health recommendations and traditional food practices (58, 59). Health professionals in this study acknowledged that national programs rarely question the cultural adaptability of their recommendations or offer alternatives that respect diverse food habits, particularly important for the migrant communities. Despite these difficulties, school feeding programmes are viewed positively, especially by families who do not have sufficient support networks to ensure safe spaces for feeding or who are forced to prioritise work over childcare. Efforts to make health service dietary guidelines more flexible and learn about the food traditions of migrant communities are viewed positively by migrant families and health teams.

The intersection of migration, social inequality, and cultural dissonance produces a “double nutritional vulnerability” for migrant children. On one hand, they face a risk of undernutrition due to material deprivation, food insecurity, and barriers to public programs. On the other hand, prolonged exposure to Chile’s food environment may eventually shift them toward overweight and obesity, replicating patterns observed in other migrant populations over time (24). This transition reflects a form of “nutritional acculturation,” in which traditional dietary patterns are progressively replaced by energy-dense, processed foods that are more affordable but nutritionally poor (29, 30).

Chile’s public health response thus faces a paradox. While the country continues to strengthen obesity prevention (60), it lacks a complementary approach that ensures early detection and treatment of undernutrition among migrant children. This omission risks deepening social and health inequalities. As noted by the FAO, PAHO, and WFP (61), the persistence of undernutrition among migrant and displaced children across Latin America signals the need for host countries to adopt a dual-focus strategy that addresses both ends of the malnutrition spectrum.

To close these gaps, Chile must advance toward an intercultural and equity-based model of nutritional health. Guaranteeing access to school feeding programmes for children, regardless of their immigration status, and prioritising their enrolment in social protection and primary care services are key actions to reverse the effects of food insecurity that they may have faced in their countries of origin and continue to face in the host country. This includes expanding access to JUNAEB; adapting nutritional guidelines to recognize diverse food cultures; and training health professionals in community-based interventions. Evidence from this type of interventions in Latin America suggests that integrating cultural identity into nutrition education can enhance adherence and improve child feeding practices (62, 63). Similarly, intercultural adaptations to school feeding programs, such as the inclusion of migrant families in menu design and preparation, have shown promise in promoting inclusion and dietary diversity (9).

This study has several significant limitations. First, because we relied on secondary data collected by the Chilean government, our analyses were constrained by the structure and quality of those existing sources. While the CASEN survey is publicly accessible, the REM dataset required a special access request. As a result, the availability of specific variables and data elements may be limited for researchers seeking to replicate or extend this work. Such access restrictions may also impact the comparability of future analyses. Despite these limitations, this work provides the first mixed-methods evidence on differences in the nutritional status of migrant and Chilean children and adolescents, addressing a critical gap in the literature. The qualitative component has a few limitations. We recognize potential bias in including only three regions in Chile (i.e., Tarapacá, the Metropolitan Region, and O’Higgins), as this may not reflect what happens across the entire country. Furthermore, we did not conduct in-depth interviews with children or adolescents; we only interviewed caregivers and professionals. Thus, we may have lost some essential details about migrants’ nutritional health. Lastly, due to the nature of qualitative methods, we cannot generalize these findings, as we used convenience sampling to identify nuances and subjectivity rather than generalization or patterns.

In summary, Chile’s current focus on childhood overweight and obesity, while justified by epidemiological trends, must be complemented by policies that address the silent and growing problem of undernutrition among migrant children. This requires moving beyond a one-size-fits-all model to a rights-based approach that ensures equitable access to adequate food and health care for all children living in Chile, regardless of their nationality or migration status. Addressing undernutrition today is essential to prevent the reproduction of health inequalities and to uphold Chile’s long-standing commitment to social protection and child well-being.