Abstract
Background
High consumption of ultra-processed foods (UPFs) is increasingly common in children and may impact respiratory health. Evidence on whether healthy diets can counterbalance these effects is limited.
Methods
In this cross-sectional study, we enrolled children from 5 schools in Northern Italy. A parental food frequency questionnaire enabled assessment of UPF intake and adherence to the Mediterranean diet (AMD; KIDMED index). Lung function and respiratory symptoms were assessed through spirometry and a standardised questionnaire. Mixed linear and logistic models, adjusted for age, sex, BMI, and smoke exposure (random intercept: school), were used and repeated, excluding asthmatic children.
Results
Overall, 315 children (8–11 years, 47% females) were included in a complete-case analysis. Greater UPF consumption was associated with poorer lung function, particularly FVC. Children in the lowest UPF tertile had higher FVC compared to those in the highest tertile. (β = 0.10 L, 95%CI 0.01 to 0.19, p = 0.031), with attenuation after excluding asthmatics (p = 0.065). Similar but weaker patterns were observed for FEV1 (p = 0.084 and p = 0.161, respectively). AMD alone was not associated with lung function. However, moderate adherence was associated with higher FVC and FEV1 among children with low-to-medium UPF intake (FVC β = 0.33 95%CI 0.12 to 0.55, p = 0.002; β = 0.27 95%CI 0.07 to 0.46, p = 0.007; FEV1 β = 0.21, 95%CI 0.02 to 0.40, p = 0.034; β = 0.22 95%CI 0.05 to 0.40, p = 0.014), suggesting a mitigation of the adverse effects of UPF consumption. Additionally, a 10% increase in UPF intake was associated with higher odds of snoring (OR = 1.38, 95%CI 1.06–1.79, p = 0.015), while higher AMD was protective (OR = 0.81, 0.71–0.94, p = 0.004).
Conclusions
High UPF intake may compromise respiratory health in children, while moderate AMD may mitigate these effects. Promoting healthy diets and reducing UPF intake in childhood could be an effective and scalable strategy for health prevention.
Key messages
• Ultra-processed food intake is associated with lower lung function in children.
• Moderate adherence to the Mediterranean diet may mitigate harms of ultra-processed foods.