RFK Jr overstates early evidence ketogenic diet treats schizophrenia

Speaking at the Tennessee state capitol February 5, 2026, Kennedy told the audience a Harvard University doctor had "cured schizophrenia using keto diet."

Clips from the speech spread rapidly on X, Facebook, Instagram and Threads.

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Screenshot of an X post taken February 9, 2026

He went on to tout additional mental health impacts of dietary changes and described the new government guidance on nutrition as asking people to "eat real food, eat protein."

The guidelines push consumption of red meat and full-fat dairy, foods many nutritionists had previously discouraged. They also emphasize protein, even as experts say most Americans do not need to consume dramatically more.

The ketogenic diet is not high-protein, but a high-fat, low-carbohydrate plan designed to force the body to change the brain's fuel source (archived here and here). It is the subject of many ongoing studies aimed at understanding how it can impact severe mental illnesses such as schizophrenia.

AFP reached out to HHS for more information on Kennedy's claim, but no response was forthcoming.

He appears to have been referencing the research of Christopher Palmer, a McLean Hospital and Harvard Medical School psychiatrist (archived here).

But Palmer told AFP on February 6 that while he thanks the health secretary for showing interest in his work, he clarified that he had "never used the word cure in any of my presentations or any of my work."

He said individual successes have shown the potential of ketogenic therapies in psychiatry, and that he is encouraged by larger, randomized trials under way.

Diet interventions

Palmer and other researchers AFP spoke with pointed to longstanding results that show a ketogenic diet helps manage seizures in epilepsy patients who do not respond to medication (archived here).

He said because epilepsy medications are regularly used off-label -- or outside of their Food and Drug Administration approved indications -- to treat psychiatric conditions, it also makes sense to examine dietary interventions that have proven effective at regulating brain activity (archived here). 

He has published several case studies showing dramatic improvement in symptoms for patients who adhere to strict dietary changes (archived here).

But he said those patients generally continue receiving medication to treat their schizophrenia in addition to attempting a ketogenic therapy diet, particularly for the first three months of such an intervention, and that medical supervision is crucial.

Cristiano Chaves, academic psychiatrist and assistant professor at McMaster University, told AFP that preliminary evidence "shows promising potential as an add-on treatment for schizophrenia," but needs to be replicated in larger trials (archived here).

"In schizophrenia, increasing evidence indicates that certain brain areas, particularly the prefrontal cortex, may struggle to use glucose (sugar) efficiently," he said in a February 7 email, meaning a diet to force the liver to burn fat into ketones may provide a new energy source for the brain.

Studies are testing the hypothesis that "ketones may enhance the performance of mitochondria (the power plants of our cells), reducing oxidative stress and inflammation that often accompany severe mental illness," he said.

Stanford trial

One Stanford University pilot study, which followed 21 participants and was published in 2024, is also often cited as a key indicator of the success of the keto diet as a treatment (archived here).

Lead investigator Shebani Sethi told AFP on February 6 (archived here): "The evidence and results so far are suggesting that metabolic interventions may benefit a subset of patients with serious mental illness."

She emphasized, however, that the dietary interventions are "moderate in protein."

"It's not high in protein, which is commonly misunderstood." 

Sethi said that people who struggle with mental illness often suffer higher rates of heart disease, stroke, type 2 diabetes and insulin resistance, and that they may be taking medications that lead to metabolic side effects (archived here).

She said studies are rigorously examining the impacts of the diet on a patient's weight, visceral fat and cardiovascular risk, in addition to mental health outcomes -- often also seeing initial improvements in metabolic syndrome.

The main challenges come if patients are unable to adopt a lifestyle that will be conducive to the dietary interventions.

"But the more that people are educated around what's actually in their food, the more likely people are going to be successful in making a change," Sethi said.

Long-term risks?

Despite the potential upsides, studies in mice have also shown long-term risks of keto, including fatty liver disease.

One paper detailing these risks was led by Amandine Chaix, assistant professor of nutrition at The University of Utah (archived here), who told AFP that while the findings can inform other trials, they are not immediately translatable to humans.

McMaster's Chaves also said there are long-term concerns related to "cholesterol levels, kidney function, nutrient balance, and overall cardiovascular risk, particularly if the diet is poorly designed or unsupervised."

Patients should receive "medical screening, monitoring, and professional supervision," he said. 

Read more of AFP's reporting on health misinformation here.