Nutrition, diabetes, and mental disorders are interconnected and significantly impact an individual's overall health and well-being. This comprehensive review aims to explore the complex interplay between nutrition, diabetes, and mental disorders, highlighting the latest research findings in this field. While the influence of nutrition on the development and management of both diabetes and mental disorders is widely recognized, there remains a gap in understanding the intricate interplay between nutrition, mental health, and diabetes. Diabetes is associated with an increased risk of mental disorders, including depression, anxiety, and cognitive decline. Mental disorders can also contribute to the development of diabetes through various mechanisms including increased stress, poor self-care behaviors, and adverse effects on glucose metabolism. Thus, the mechanisms linking nutrition, diabetes, and mental disorders are complex and multi-factorial. Inflammation, oxidative stress, gut microbiota alterations, and neuroendocrine dysregulation have emerged as potential pathways that may mediate the relationship between nutrition, diabetes, and mental disorders. Additionally, deficiencies in essential nutrients such as omega-3 fatty acids, vitamin D, B vitamins, zinc, chromium, magnesium, and selenium have been implicated in the pathogenesis of both diabetes and mental disorders. Our findings indicate that the use of personalized dietary interventions and targeted nutrient supplementation can improve metabolic and mental health outcomes in patients with type 2 diabetes.