Association between ultra-processed food consumption, sociodemographic characteristics, malnutrition and obesity among urban school-aged children in Lilongwe, Malawi: a cross-sectional study

Introduction The escalating consumption of ultra-processed foods (UPFs) among school-aged children in developing countries poses a significant threat to public health, contributing to the dual burden of malnutrition. In Malawi, where undernutrition coexists with a burgeoning obesity epidemic, understanding the determinants of UPF consumption and its impact on children's nutritional status is imperative. This study, conducted in Lilongwe, Malawi, aimed to investigate the association between UPF consumption, sociodemographic factors and the nutritional status of school-aged children.Materials and methods 511 children aged 7-14 were recruited from 2 densely populated townships using systematic random sampling. Data on sociodemographic factors, UPF consumption and nutritional status were collected through face-to-face interviews and anthropometric measurements. UPF consumption was assessed using a validated Food Frequency Questionnaire while multinomial logistic regression was employed to analyse associations.Results Results revealed alarmingly high UPF consumption among children, particularly those high in sugar. Multinomial logistic regression identified significant predictors of malnutrition outcomes. Notably, children consuming UPFs more than three times a week were more likely to be malnourished. Overweight status was positively associated with sausage intake (beta=0.226, adjusted OR 1.254, 95% CI 1.004 to 1.566, p=0.046) and age (beta=0.020, adjusted OR=0.257, 95% CI 0.156 to 0.28, p=0.003). Conversely, underweight status was linked with residential location (beta=4.507, adjusted OR 0.01, 95% CI 0.000 to 0.281, p=0.006) and fizzy drinks (beta=1.071, adjusted OR 2.919, 95% CI 1.413 to 6.028, p=0.004).Conclusion The high prevalence of UPF consumption among school-aged children is significantly associated with malnutrition. Moreover, sociodemographic factors influence UPF consumption, highlighting the need for targeted interventions to reduce malnutrition. These findings may inform public health policies to mitigate malnutrition among children in Malawi's urban communities.