Ultra-Processed Foods as a Cross-Cutting Driver of Health Inequities: Low- and Middle-Income Countries Across the Life-Course.

Ultra-processed foods (UPFs) have become a growing part of everyday diets worldwide and have been linked to obesity, non-communicable diseases, and adverse mental health outcomes. Yet their role in deepening nutritional and health inequalities across socioeconomic groups and different stages of life is still not fully addressed in policy discussions. Drawing on recent population-based studies, longitudinal surveys, and mechanistic evidence, this perspective examines how UPF consumption intersects with food insecurity, psychosocial distress, and neurodevelopmental health from pregnancy through adulthood. Evidence from the United States shows that adults experiencing food insecurity obtain a larger share of their daily energy from UPFs. At the same time, surveys from low- and middle-income countries (LMICs) show that many infants and young children are already consuming sugar-sweetened beverages. Other observational studies have linked higher UPF intake with addictive-like eating behaviours and symptoms of depression, anxiety, and stress, although these studies cannot yet prove causality. In many LMICs, ongoing dietary transitions are also contributing to a rapid increase in overweight and obesity among socioeconomically disadvantaged groups, even while childhood stunting declines only slowly. Together, these findings suggest that UPF exposure is not only a dietary issue, but also a marker of wider social and nutritional vulnerability across the life-course. Breaking this cycle will require coordinated policy action, including stronger restrictions on unhealthy food marketing, front-of-package warning labels, better regulation of foods marketed to infants and young children, reforms to food-assistance programmes, and fiscal measures that make minimally processed foods more affordable and accessible.