Ultra-Processed Foods and Health Outcomes in Children and Adults: An Updated Narrative Umbrella Review With a Focus...

Ultra-processed foods (UPFs) now contribute a substantial share of total energy intake. A growing body of evidence has linked UPF consumption to adverse health outcomes, but existing umbrella reviews are mainly restricted to studies published before mid-2023 and have seldom rigorously examined the shape of dose-response relationships, evaluating both linearity and nonlinearity. The aim of this study was to synthesize updated meta-analytic evidence on associations between UPF consumption and major health outcomes in children and adults. A narrative umbrella review synthesized meta-analyses of studies published through December 9, 2025. Outcomes included obesity, type 2 diabetes (T2D), cardio-cerebrovascular diseases (CCVDs), nonalcoholic fatty liver disease (NAFLD), cognition, mental health (anxiety and depression), dental health, cancer, and all-cause mortality. For each outcome, a lead meta-analysis was selected by comprehensiveness, recency, and methodological quality (separately for children and adults when feasible). Methodological quality was assessed using a ROBIS (Risk of Bias Assessment Tool for Systematic Reviews)-adapted tool. Certainty of evidence was rated with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Twelve lead meta-analyses (mainly from observational studies) covering 13 outcomes were identified (4/13 in children). Across all but 1 outcome, higher (vs lower) UPF consumption was associated with increased risk (see graphical abstract). Dose-response evidence indicated a 10% higher risk per 10% increase in UPF intake for T2D, a curvilinear risk increase for CCVDs, and no significant association for NAFLD; for other outcomes, rigorous dose-response analyses were lacking. Certainty of evidence was high for 1 outcome, moderate for 6, and low for 6 other outcomes. This updated umbrella review confirmed harmful associations of UPFs with multiple health outcomes, and added insights on children's health, cognition, dental health, CCVDs, and dose-response. Despite remaining methodological gaps (including observational-based and nonrigorous dose-response analyses), current evidence supports population-wide strategies to reduce UPF intake. Systematic Review Registration: PROSPERO registration no. CRD420251230427.