Patterns of Ultra‐Processed Food Consumption and Their Associations With Body Composition in Primary School Children in Semarang City, Indonesia

AIMS: This study aimed to examine the association between ultra-processed food (UPF) consumption and body composition among primary school children in Semarang City, Indonesia. METHODS: A cross-sectional study was conducted among primary school children selected from schools in Semarang City using a random sampling method. Anthropometric measurements were used to assess the body mass index (BMI), BMI-for-age Z-score, body fat percentage and muscle mass. Dietary behaviours, including UPF consumption frequency, and lifestyle factors were assessed using structured questionnaires. Multivariable linear regression analyses were performed to assess the independent association between UPF consumption and body composition outcomes after adjusting for age, sex, physical activity, screen time and meal frequency. RESULTS: A total of 334 children (mean age, 10.02 ± 0.77 years) were included in the analysis. UPF consumption was consistently associated with all body-composition indicators. Higher UPF intake was significantly associated with increased BMI (B = 1.449; 95% CI: 1.174-1.723), BMI-for-age Z-score (B = 0.589; 95% CI: 0.505-0.672) and body fat percentage (B = 3.334; 95% CI: 2.766-3.902) and decreased muscle mass (B = -1.497; 95% CI: -1.880 to -1.115) after adjustment for confounders. Other dietary and lifestyle variables were not significantly associated with the body composition. CONCLUSIONS: Higher UPF consumption was consistently associated with less favourable body composition among primary school children in Semarang City, including higher BMI, BMI-for-age Z-score, and body fat percentage and lower muscle mass. These findings highlight the importance of improving the school food environment and promoting healthier food choices among school-aged children.