People with serious mental illness die, on average, 10 to 25 years earlier than everyone else—not from suicide but from heart disease, diabetes, and metabolic failure. A growing number of researchers now believe that the ketogenic diet could be one promising solution.
The ketogenic diet, which shifts the body’s fuel source from glucose to fat-derived ketones, has long been a clinical tool for drug-resistant epilepsy. Now, early-stage research is exploring whether the same metabolic mechanisms might benefit people living with schizophrenia and bipolar disorder.
A New Approach to Treating Mental Illness
Traditionally, mental illness has been seen as a disorder of the brain alone. However, it is becoming clearer that mental health is closely associated with the body’s metabolism.
A growing body of research suggests that metabolic dysfunction—including insulin resistance, chronic inflammation, lipid imbalances, and impaired energy production at the cellular level—may play a significant role in how psychiatric conditions develop and progress.
Mental illnesses affect about 1.1 billion people worldwide, often affecting how people think, feel, and behave.
“While modern medicine offers a range of medications and therapies, these do not work for everyone,” Dr. Shebani Sethi, founder of the Metabolic Psychiatry Clinic at Stanford University, told The Epoch Times. “Because of this, scientists are starting to rethink how mental illness develops.”
One area of particular interest is mitochondrial function.
“You can think of mitochondria as the batteries inside all cells that are important for virtually all processes from stress responses to energy production,” Dr. Edward Caddye, clinical research fellow in metabolic psychiatry at the London Psychiatry Clinic, told The Epoch Times.
In many psychiatric conditions, the brain struggles to use energy efficiently. Ketones offer an alternative fuel source that may bypass some of this dysfunction—a mechanism already well-documented in epilepsy, which shares several neurochemical pathways with bipolar disorder. Many of the same medications used to control seizures are also used to stabilize mood.
This link between brain energy use and metabolic health is particularly relevant given that antipsychotic medications, while often effective, can contribute to weight gain, diabetes, and heart disease, the very conditions already shortening patients’ lives.
Concerns about these effects lead to another goal of exploring novel treatments—”reducing the burden of side effects,” Dr. Julien Trokis, a diabetologist involved in metabolic psychiatry research, told The Epoch Times.
A ketogenic diet may help address both the underlying metabolic issues of the mental illnesses and the metabolic side effects of their medications, Trokis said.
What the Research Shows
In a four-month pilot study conducted at Stanford University, participants with schizophrenia or bipolar disorder and existing metabolic issues followed a structured ketogenic diet designed to reduce carbohydrate intake to about 20 grams per day, excluding fiber. They received recipes and coaching.
The participants’ psychiatric symptoms improved by an average of 32 percent on the Brief Psychiatric Rating Scale for schizophrenia. Among those with bipolar disorder, 69 percent showed meaningful improvements, and all who adhered closely to the diet were in a recovered or recovering state. Recovery rates in schizophrenia increased from 38 percent at baseline to 81 percent.
Participants also showed improvements in weight, blood pressure, triglycerides, and other metabolic markers.
In a retrospective analysis of 31 adults with severe, treatment-resistant mental illness, including major depressive, bipolar, and schizoaffective disorders, participants followed a ketogenic diet alongside standard inpatient care.
Hamilton Depression Rating Scale scores, a clinician measure of depression severity, improved from the severe range to remission, while Montgomery-Asberg scores, which track core mood symptoms, shifted from moderate to mild. In patients with schizoaffective illness—a combination of schizophrenia symptoms with mood disorder episodes—hallucinations, delusions, and social withdrawal dropped from markedly ill to mild levels.
Adherence appears to matter significantly, as the brain seems to function best with a steady supply of ketones over time rather than intermittent exposure.
In the four-month Stanford pilot trial, 91 percent of participants who were adherent—maintaining ketosis 80 percent to 100 percent of the time—experienced significant improvements in the severity of mental illness. In contrast, only 50 percent of those with semiadherence—maintaining ketosis 50 percent to 79 percent of the time—showed similar improvements.
Although the ketogenic diet shows promise in bipolar disorder and schizophrenia, its effects can vary depending on the individual, Sethi said. It remains most established in drug-resistant epilepsy, but growing interest is extending to areas such as Alzheimer’s disease and Parkinson’s disease, as well as metabolic conditions such as Type 2 diabetes.
Your Brain on a Keto Diet
How does the keto way of eating affect the brain?
Most of the time, your brain runs on glucose, which comes from carbohydrates. When you cut back on carbs, your body switches to burning fat instead, producing molecules called ketones. Ketone bodies provide an alternative fuel source for the brain, which helps stabilize brain activity and reduce overexcitability.
Ketones are also linked to neuroprotective effects, including reduced inflammation and oxidative stress.
By shifting the brain’s fuel source from glucose to ketones, the existing mitochondrial dysfunction can be bypassed, and further damage is reduced.
Ketones are an efficient fuel, under certain conditions, producing fewer oxidative byproducts than glucose. Although this difference is subtle in a healthy system, it may become more relevant when glucose metabolism is impaired or the brain is under metabolic stress.
When Keto Isn’t Suitable
Although a ketogenic diet may benefit a range of people and conditions, it is not suitable for everyone.
It should be avoided by people with rare metabolic conditions that prevent the body from efficiently processing fat for energy, as this may worsen their conditions. Extra caution is also needed in people with inherited high cholesterol, given their already elevated low-density lipoprotein cholesterol levels and the variability in lipid responses to a ketogenic diet, and in people with conditions such as acute pancreatitis, severe liver failure, and advanced kidney disease, for whom high-fat intake can pose risks, Trokis said.
Keto therapy can interact with certain medications—including some antipsychotics and diabetes drugs—and may require dosage and other personalized adjustments.
Pregnant and breastfeeding women, children, and those with Type 1 diabetes are not suitable candidates. People with existing heart disease, particularly those with a high intake of fats, should approach the diet with caution, Trokis said.
How to Start
The next question is how to begin a ketogenic diet in a practical and sustainable way.
The classical ketogenic diet typically follows a four-to-one ketogenic ratio, meaning that the weight of fat is four times that of combined protein and carbohydrate.
In practice, maintaining this ratio involves prioritizing natural fat sources such as avocados, olive oil, coconut oil, butter, ghee, lard, almonds, walnuts, chia seeds, and flaxseeds.
Protein should be eaten in moderate amounts to preserve muscle, while avoiding excess that may be converted into glucose. Common protein sources for the keto diet include fatty cuts of meat, poultry, fish—especially salmon, mackerel, and sardines—eggs, and full-fat dairy such as cheese and Greek yogurt, Caroline Susie, a registered dietitian nutritionist, told The Epoch Times.
Carbohydrate intake is typically kept low, about 20 grams to 50 grams of net carbs per day, and should come mainly from low-carbohydrate vegetables such as leafy greens, broccoli, cauliflower, zucchini, asparagus, and peppers. Small amounts of low-sugar fruits such as berries can also be eaten. Unsweetened beverages such as tea, coffee, and water are generally included, Susie said.
Safety remains a key consideration, especially when using the diet therapeutically. Early side effects, often referred to as the keto flu, may include fatigue, headaches, and irritability during the initial adaptation phase. These symptoms are usually mild and temporary, and can be reduced by gradually lowering carbohydrate intake, maintaining adequate hydration, balancing electrolytes, and including fiber-rich, low-carbohydrate vegetables, Sethi said.
There are also nutritional considerations. Limiting fruits, whole grains, and legumes may reduce intake of certain nutrients, which, over time, may increase the risk of deficiencies, particularly without careful planning. Limited fiber intake can also contribute to constipation and digestive discomfort, Susie said.
Ongoing medical supervision, personalized adjustments, and structured support can help improve both safety and long-term sustainability. Trokis advised anyone considering a ketogenic diet to first check with his or her doctor for any contraindications and to begin under the guidance of a dietitian.
“Ideal duration of a keto diet can vary as some patients may benefit from longer-term use, while others may transition to a more flexible approach,” Trokis said.
Sethi, who led the Stanford pilot trial, said more research is needed to demonstrate the efficacy of the dietary therapy. However, the results have raised hope.
In the researchers’ interview with the participants after the trial, one patient said, “It can honestly save a lot of lives; it saved mine.”