The Influence of Ultra-Processed Foods on Inflammation and Metabolic Health in Pediatric Obesity: A Systematic Review with a Narrative Synthesis

The increasing prevalence of childhood obesity has been accompanied by an increase in consumption of ultra-processed foods (UPF), characterized by high energy density and low nutritional quality. Emerging evidence suggests that dietary patterns rich in UPF may contribute to low-grade systemic inflammation and early metabolic dysfunction in children and adolescents. Objective: This systematic review aimed to evaluate the association between UPF consumption and markers of inflammation and metabolic health in pediatric populations. Methods: A systematic literature search was conducted on PubMed in accordance with PRISMA guidelines. Observational and interventional studies evaluating UPF intake or diet-related inflammatory potential in children and adolescents (≤18 years) were included. Outcomes of interest included inflammatory biomarkers (e.g., C-reactive protein, interleukins, tumor necrosis factor-α) and metabolic parameters (e.g., insulin resistance, lipid profile, glucose metabolism). Results: A limited number of studies have directly assessed UPF consumption using the NOVA classification. Overall, these studies suggest a potential association between increased UPF intake and adverse metabolic outcomes, although findings on inflammatory markers remain inconsistent. A larger body of indirect evidence, including studies assessing dietary inflammatory indices and related dietary patterns, consistently supports a link between pro-inflammatory diets and increased inflammation and metabolic dysregulation in pediatric populations. Conclusions: Although direct evidence on UPF consumption remains limited, the available findings, supported by complementary indirect evidence, suggest a plausible relationship between UPF-rich diets, inflammation, and metabolic health in children and adolescents. Further well-designed studies are needed to clarify causality and improve the standardization of dietary assessment methods.