Chewing on Change: How Fast Food Shapes Human Tooth Morphology and Oral Health

Background: The worldwide adoption of diets dominated by fast food characterized by refined sugars, simple carbohydrates, and ultra‑processed ingredients has been linked to rising rates of tooth decay, enamel erosion, and periodontal disease. These dietary changes also coincide with long‑term shifts in dental wear patterns and jaw morphology driven by reduced masticatory demand. Objective: This review aims to synthesize current evidence on how habitual fast‑food consumption affects tooth structure and function, including enamel thickness, occlusal morphology, and mandibular robustness, and to explore the genetic and evolutionary mechanisms that mediate these effects. Methods: We conducted a targeted search of major scientific databases using keywords related to fast food, dental evolution, oral health, and genetic adaptation. Studies were selected if they examined enamel microstructure, dental wear, epidemiological associations with oral pathology, or the role of genetic variation in enamel resilience. Data from clinical surveys, anthropological analyses, and molecular genetics were extracted and compared to identify common patterns. Results: Populations with high fast‑food intake exhibit notable enamel thinning and elevated prevalence of caries and periodontal conditions. Comparative analyses of prehistoric and modern samples reveal a reduction in dental attrition and a trend toward smaller, less robust molars and narrower jaws following the advent of convenience foods and cooking technologies. Genetic investigations highlight that variation in enamelin and other loci contributes to differential enamel durability, while prolonged consumption of soft, processed diets has relaxed selective pressures on tooth and jaw strength, enabling genetic drift to narrow allelic diversity. Conclusion: Habitual fast‑food diets not only exacerbate immediate oral‑health issues but also appear to drive evolutionary trends toward reduced dental robustness. A multidisciplinary approach integrating clinical dentistry, anthropology, and genomics is essential to develop preventive strategies that safeguard both current oral health and the long‑term evolutionary potential of the human dentition.