A randomized controlled trial found that a ketogenic diet significantly improved metabolic health, cognitive performance, and psychiatric symptoms in people with schizophrenia-spectrum and bipolar I disorders, with improvements in depressive symptoms linked to ketosis rather than weight loss. In this study, 58 outpatients were randomized to either a ketogenic diet or their usual diet for one month, and a subgroup continued the ketogenic diet for four months. Participants on the ketogenic diet consistently achieved nutritional ketosis and experienced greater reductions in body weight, hemoglobin A1c, and insulin resistance than those receiving their usual diet after one month. After four months on the ketogenic diet, significant improvements were observed in positive and negative psychotic symptoms, depressive symptoms, and cognitive performance. Higher blood ketone levels were associated with greater improvements in prediabetes-related metabolic markers and depression, while the amount of weight lost was not associated with these metabolic or psychiatric benefits. These findings demonstrate that a ketogenic diet is feasible for outpatients with schizophrenia-spectrum and bipolar I disorders and suggest that ketosis itself, rather than weight loss, may be the key mechanism underlying its metabolic and mental health benefits. Source: https://academic.oup.com/
