The rapid global rise in the consumption of ultra-processed foods (UPFs) has become a major public health concern. UPFs are industrially manufactured products rich in added sugars, unhealthy fats, and sodium, while being low in essential nutrients and dietary fiber. This review explores the relationship between UPF consumption and long-term health outcomes, including obesity, type 2 diabetes, cardiovascular diseases, and certain cancers. Using evidence from recent epidemiological and clinical studies, the paper highlights the biological mechanisms linking UPFs to metabolic dysregulation, gut microbiota imbalance, inflammation, and endocrine disruption. The review also discusses the socio-economic and behavioral determinants influencing UPF intake, such as urbanization, affordability, and aggressive food marketing. Furthermore, it emphasizes the role of policy measures—such as front-of-pack labeling, reformulation strategies, and public awareness programs—in reducing UPF consumption. Promoting minimally processed, nutrient-dense traditional diets is essential for improving population health and achieving sustainable food systems.