This case series reports the successful use of a personalized ketogenic diet (KD) in three adults with complex psychiatric comorbidities, achieving complete remission of major depression and generalized anxiety disorder within 7–12 weeks. The patients, aged 32–36, were treated with a 1.5:1 ratio of fat to protein plus carbohydrates, along with personalized nutritional ketosis, dietary counseling, and lifestyle interventions. All three patients experienced significant improvements in depression, anxiety, self-compassion, and metabolic health. Two patients achieved remission within 7 weeks, while one required 12 weeks. Metabolic improvements included weight loss, reduced body fat, and normalization of blood pressure and lipid profiles. The study highlights the potential of KD as a therapeutic option for psychiatric conditions, particularly in individuals with complex comorbidities. The results suggest that KD can be an effective and sustainable treatment for depression and anxiety, with potential benefits for metabolic health. The study also emphasizes the importance of individualized treatment plans and the role of metabolic health in mental health outcomes. The findings contribute to the growing body of evidence supporting the use of KD in psychiatric care.This case series reports the successful use of a personalized ketogenic diet (KD) in three adults with complex psychiatric comorbidities, achieving complete remission of major depression and generalized anxiety disorder within 7–12 weeks. The patients, aged 32–36, were treated with a 1.5:1 ratio of fat to protein plus carbohydrates, along with personalized nutritional ketosis, dietary counseling, and lifestyle interventions. All three patients experienced significant improvements in depression, anxiety, self-compassion, and metabolic health. Two patients achieved remission within 7 weeks, while one required 12 weeks. Metabolic improvements included weight loss, reduced body fat, and normalization of blood pressure and lipid profiles. The study highlights the potential of KD as a therapeutic option for psychiatric conditions, particularly in individuals with complex comorbidities. The results suggest that KD can be an effective and sustainable treatment for depression and anxiety, with potential benefits for metabolic health. The study also emphasizes the importance of individualized treatment plans and the role of metabolic health in mental health outcomes. The findings contribute to the growing body of evidence supporting the use of KD in psychiatric care.