Dietary Responses to Non-Communicable Chronic Disease Diagnoses—A Scoping Review

Background: Non-communicable chronic diseases (NCDs) have become a significant health burden, and diet plays a critical role in NCD prevention and management. Methods: This review systematically synthesizes evidence (up to June 30, 2025) on dietary changes among patients following the diagnoses of NCDs, including cancer, diabetes, chronic inflammatory diseases, hypertension, and other NCDs. A comprehensive literature search based on PubMed, Web of Science, Google Scholar, and ScienceDirect identified 38 studies that met the inclusion criteria. Results: Among the studies included in this review, those on cancer diagnoses account for the largest proportion (45%), followed by studies on the diagnoses of diabetes and hypertension. The United States has the largest number of studies, primarily on cancer and diabetes diagnoses, followed by China, predominantly on hypertension diagnoses. The remaining studies were conducted sparsely in European and Asia-Pacific countries. While approximately 60% of the studies reported desirable dietary responses following NCD diagnoses, significant heterogeneity across regions and specific types of NCDs were also discovered: (1) cancer-related studies yielded mixed results: most discovered desirable dietary changes, while some observed undesirable adjustments; (2) diabetes patients prioritized reductions in carbohydrates, but recently regression-discontinuity designs have shown little impact of diabetes diagnoses; (3) hypertension patients generally reduced their sodium and alcohol consumption, with responses differ across diagnostic thresholds; (4) chronic inflammatory disease patients tended to avoid symptom-triggering foods; (5) patients with other NCDs (mainly cardiovascular conditions) slightly reduced their alcohol intake. Conclusion: While existing research has provided considerable evidence on individuals’ dietary responses to NCD diagnoses, limitations remain, including uneven geographical and disease coverage, inconsistent dietary assessment methods, insufficient sample representativeness, and inadequate capabilities for causal identification. Future studies should expand geographical and disease coverage, improve diet assessment methods, and strengthen causal design to enhance clinical and public health strategies for NCD management. Keywords: non-communicable chronic diseases, dietary changes, disease diagnosis, scoping review