The collapse of the food matrix: how ultra-processed foods impact satiety and metabolism by altering physical structure beyond nutrient composition.

The global consumption of ultra-processed foods (UPFs) is strongly associated with the prevalence of non-communicable diseases (NCDs). This link has traditionally been attributed to their poor nutritional profiles. However, evidence shows that even when nutrient-matched, UPFs promote excess energy intake and weight gain, suggesting a pathogenic mechanism beyond their chemical composition. This review proposes a central conceptual framework: the core threat of UPFs to health may originate profoundly from the industrial collapse of their physical "food matrix." While evidence-informed, this framework remains a conceptual proposition requiring further causal validation. We hypothesize that this structural disintegration triggers a proposed top-down cascade of dysregulation. In the oral phase, a soft matrix accelerates eating rates by reducing chewing requirements, thereby weakening early satiety signals. In the gastrointestinal tract, the excessively rapid absorption of nutrients suppresses the secretion of distal gut satiety hormones, such as glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). This supraphysiological nutrient flux imposes a significant challenge on core metabolic organs, driving insulin resistance and hepatic de novo lipogenesis. Ultimately, the impoverished matrix leads to gut microbiota imbalance, compromised intestinal barrier function, and low-grade systemic chronic inflammation. In conclusion, the integrity of the food matrix is an indispensable dimension for evaluating the health value of food. This paper calls for a fundamental shift in perspective within nutritional science and public health policy: from focusing solely on "what is in our food" to equally considering "what has been done to our food."