This study examined the socio-economic and demographic determinants of undernutrition among children aged 6–59 months in Malawi, revealing several significant associations between these factors and nutritional outcomes. The findings indicated that socio-economic factors such as occupation, marital status, household size, and educational level of caregivers were significantly associated with the three indicators of undernutrition: wasting, underweight, and stunting.

The lower odds of wasting among children from households engaged in farming or business activities align with prior studies suggesting that agricultural and entrepreneurial occupations may provide better food security and access to resources, particularly in rural settings. For example, Kumar et al. found that farming households in rural India had better access to food, which contributed to improved child nutrition [12]. Similarly, Buo et al. highlighted that income from agricultural activities in rural Ghana plays a protective role against child malnutrition [13]. In contrast, this study found that unemployment was a significant risk factor for stunting, which is consistent with research conducted in rural sub-Saharan Africa, where low household income was found to be a significant predictor of poor nutritional outcomes [14]. However, studies in other regions, such as rural Bangladesh, have reported no significant relationship between employment status and stunting, suggesting that other factors may also influence child nutritional status in different contexts [15].

Children from single-parent households had higher odds of being underweight, which may reflect the challenges faced by single caregivers in meeting the nutritional needs of their children. This finding is in line with previous studies in rural settings, such as Inbaraj et al., which noted that single-parent households in rural Indonesia often struggle with resource allocation, leading to poorer nutrition outcomes for children [16]. However, a study by Roba KT, et al. in rural Ethiopia found that single-parent status was not significantly associated with malnutrition, suggesting that variations in community support systems may influence these outcomes [17].

Household size also played a role in nutritional outcomes, with smaller households (< 5 members) being less likely to have underweight children. This could be due to more focused caregiving and resource allocation in smaller families, a factor observed in rural areas where family dynamics significantly influence child nutrition. Similar findings were reported by Kara et al. in rural Zambia, where smaller households had a lower incidence of underweight children due to more equitable distribution of food and resources [18].

The protective effect of vaccination against wasting and the significant association between educational level and underweight further emphasize the critical role of health interventions and maternal education in improving child nutrition. Studies in rural Africa have shown that maternal education is strongly linked to better child health and nutrition outcomes, as educated mothers are more likely to adopt improved feeding practices [19]. For example, research by Mutanda et al. in rural Zimbabwe found that higher levels of maternal education were associated with a reduced risk of child undernutrition.

Religious affiliation was another significant factor, with Muslim children showing higher odds of wasting compared to their Christian counterparts. This finding warrants further investigation to understand the cultural and dietary practices that may contribute to this disparity. Studies in rural contexts, such as Lokossou et al., have noted that religious beliefs often shape dietary patterns and may influence nutritional outcomes, particularly in rural communities where cultural practices are more pronounced [20]. However, a study by Adebayo et al., Daniel Major-Smith and Thamae Retselisitsoe and Ntoi Neo found no significant differences in child nutritional status based on religious affiliation, suggesting that other socio-economic and health-related factors may play a more influential role [21,22,23].

Moreover, the results suggest that full vaccination was protective against wasting, reinforcing the importance of immunization in preventing undernutrition and its related complications. This finding is supported by studies in rural health interventions, such as Prendergast AJ., which emphasized the protective role of vaccination programs in reducing child malnutrition in rural sub-Saharan Africa [23]. Similarly, a study in rural Tanzania and other developing countries highlighted the positive impact of vaccination on child nutrition, showing a lower prevalence of wasting among vaccinated children compared to those who were not immunized [23,24,25,26,27].

This study used a cross-sectional design, which means data was collected at one point in time. As a result, the study can only show links between socio-demographic factors and undernutrition but cannot confirm whether these factors directly cause undernutrition. For example, while certain factors like occupation or household size are associated with malnutrition, it is unclear if they occurred before or after the condition developed.

The study focused on three districts—Mzimba, Mchinji, and Mangochi—which have unique social and economic conditions. Because of this, the results may not apply to other regions in Malawi or areas with different cultural, economic, or environmental settings. Therefore, caution is needed when trying to apply these findings to other populations.

It is recommended that future research focus on exploring the causal relationships between socio-economic factors and child malnutrition through longitudinal study designs, which would offer deeper insights into how these factors influence children’s nutritional outcomes over time. Additionally, studies should assess the long-term impact of interventions targeting maternal education and household income on improving child nutrition. Investigating cultural practices and dietary restrictions across various religious groups in Malawi could enhance understanding of the role religion plays in child nutrition, while examining regional variations, particularly between urban and rural settings, would allow for the development of tailored, region-specific interventions to improve nutritional outcomes.