Ketogenic Diet for Mental Illness: Is Kennedy Right?

On Friday, February 6, 2026, during an event at the Tennessee State Capitol, Robert F. Kennedy Jr., United States Secretary of Health, claimed that the ketogenic diet could cure schizophrenia and bipolar disorder. “We now know that what you eat is the cause of mental illness in this country. » He notably declared that a Harvard doctor had “cured schizophrenia thanks to a ketogenic diet”, according to the newspaper The Independent.

These comments are a continuation of the presentation, last January, of the new American nutritional recommendations which promote raw foods, proteins and good fats. “So it doesn’t just affect our physical health, it also affects our mental health. And people are being asked now, eat real food, eat protein,” he concluded.

To find out more, read our article published in Le Monde de la nutrition in February 2026, dedicated to the new American nutritional recommendations

A cautious reaction from experts

After this position, several experts reacted to moderate or even refute these assertions. Thus, Columbia psychiatrist Mark Olfson said “There is currently no credible evidence that ketogenic diets cure schizophrenia. »

According to the ScientificAmericanJeff Volek, a professor at Ohio State University who has conducted research on the ketogenic diet, says he is not aware of any published clinical studies showing that the diet can cure schizophrenia. He adds, however, that he would not be surprised if some individual cases showed improvement in schizophrenia symptoms that could be attributed to the diet. Especially, “As a scientist, I personally would not use such a strong term (as “cure”) without more definitive evidence from rigorous scientific studies,” he said.

What is the ketogenic diet?

The ketogenic (or keto) diet is a diet that is very low in carbohydrates and high in fat. Concretely, it limits carbohydrate intake to around 20-50 grams per day (or around 5% to 10% of total calories), while fats represent 70 to 80% of daily caloric intake, and proteins 20 to 25%.

By drastically reducing carbohydrates, the body enters ketosis: it produces molecules called “ketone bodies” which become the main source of energy for the brain and cells, replacing glucose.

Initially developed to treat epilepsy, this diet is now attracting the interest of researchers for other pathologies, notably metabolic diseases and, more recently, psychiatric disorders.

Promising preliminary studies

Certainly there is no large randomized controlled clinical trial to support Kennedy’s remarks, but several preliminary studies (pilot studies, case studies, etc.) demonstrate the therapeutic potential of the ketogenic diet on mental illnesses. Here we present three of the most recent ones.

• In 2019, Harvard researchers described the case of two schizophrenia patients in remission thanks to a ketogenic diet (1). In a comment published in Psychology Todayone of the authors of this work, Christopher Palmer, explained that “ What is particularly interesting about our research is that both patients were able to stop their antipsychotic treatment and have been in remission for several years now. »
• In 2022, a French study tested the ketogenic diet on 31 patients suffering from serious mental illnesses (depression, bipolarity, schizophrenia) resistant to traditional treatments. Results: 28 of 31 patients completed the study with significant improvement in psychiatric symptoms within 3 weeks, improved metabolic health, 64% reduced medications, and 43% achieved clinical remission (2).
• In 2024, a pilot study of 21 schizophrenic or bipolar adults taking antipsychotics tested a ketogenic diet for four months (3). Three-quarters of participants improved their mental health (better sleep, energy, mood and quality of life), while benefiting from metabolic improvements: loss of 10% of body weight and improvement in certain health markers (blood pressure, blood sugar, triglycerides, insulin resistance).

How the ketogenic diet can affect mental health

By correcting metabolic disorders, the ketogenic diet could improve the mental health of patients. According to Dr. Albert Danan, a psychiatrist in Toulouse who led the French study, “the ketogenic diet acts on 3 main axes: insulin resistance – it restores insulin sensitivity – it reduces inflammation, and it provides a new source of energy, ketone bodies, which constitute a much more efficient fuel for brain cells. » All this would help reduce psychiatric symptoms.

The ketogenic diet also acts on several neurotransmitter systems involved in depression or schizophrenia. It would also reduce oxidative stress, implicated in the poor functioning of mitochondria, the energy plants of cells.

Dr. Georgia Ede, author of the book Nourish your brain, heal your mindis of the same opinion: “The ketogenic diet may address the root causes of schizophrenia symptoms”she said. And this diet is also promising against bipolar disorder: “Three case reports have been published of women with bipolar disorder who found the ketogenic diet so helpful that they were able to stop all mood-stabilizing medications. » For example, a study of two women with bipolar disorder showed that they were able to maintain ketosis for extended periods of time (2 and 3 years, respectively) and experienced a stabilization of their mood (4).

To find out more: Nourish your brain, heal your mind