Dietary interventions significantly influence human health and disease progression, particularly in cancer, neurodegenerative, autoimmune, cardiovascular, and metabolic disorders. These interventions modulate metabolism, disease trajectory, and therapeutic responses. Metabolic reprogramming in tumors affects immune regulation, and dietary factors can influence tumor metabolism. Dietary interventions, such as calorie restriction, fasting-mimicking diet, ketogenic diet, protein restriction, high-salt, high-fat, and high-fiber diets, have shown potential in cancer and other diseases by altering immune responses, metabolic pathways, and gut microbiome composition. These interventions can enhance the efficacy of cancer treatments and modulate immune responses. The review explores the molecular mechanisms and therapeutic potential of various dietary interventions in disease management. It highlights the complex interplay between diet, metabolic reprogramming, and disease progression, emphasizing the need for further research to fully understand and utilize these interventions in clinical settings. The review also discusses the unique metabolic characteristics of tumors and the impact of dietary interventions on immune cell metabolism, including glucose, lipid, and amino acid metabolism. The findings suggest that dietary interventions can be valuable adjunctive therapies in disease management, although challenges remain in their clinical application due to potential side effects and the need for personalized approaches.Dietary interventions significantly influence human health and disease progression, particularly in cancer, neurodegenerative, autoimmune, cardiovascular, and metabolic disorders. These interventions modulate metabolism, disease trajectory, and therapeutic responses. Metabolic reprogramming in tumors affects immune regulation, and dietary factors can influence tumor metabolism. Dietary interventions, such as calorie restriction, fasting-mimicking diet, ketogenic diet, protein restriction, high-salt, high-fat, and high-fiber diets, have shown potential in cancer and other diseases by altering immune responses, metabolic pathways, and gut microbiome composition. These interventions can enhance the efficacy of cancer treatments and modulate immune responses. The review explores the molecular mechanisms and therapeutic potential of various dietary interventions in disease management. It highlights the complex interplay between diet, metabolic reprogramming, and disease progression, emphasizing the need for further research to fully understand and utilize these interventions in clinical settings. The review also discusses the unique metabolic characteristics of tumors and the impact of dietary interventions on immune cell metabolism, including glucose, lipid, and amino acid metabolism. The findings suggest that dietary interventions can be valuable adjunctive therapies in disease management, although challenges remain in their clinical application due to potential side effects and the need for personalized approaches.