Ketogenic Diet: Decreasing Depression, Fighting Fat, Defeating Diabetes

Diets come and diets go with amazing predictability. The standard American diet has shortcomings, so people are frequently eager for an approach to nutrition that will be healthful. A ketogenic diet has been an option for at least a hundred years. A recent pilot study suggests yet another possible application, this time in psychiatry. Could a ketogenic diet decrease depression?

History of the Ketogenic Diet:

Epilepsy (Seizure Disorders):

In the early 20th century, when there were few effective drugs to treat epilepsy, doctors prescribed starvation or a very low-carbohydrate high-fat diet (Epilepsia, Nov. 4, 2008). Such a regimen forced the body to burn fat rather than carbohydrates for energy and resulted in the formation of ketones (explaining the term ketogenic diet).

This dietary approach frequently reduced the number of seizures epileptic children suffered. Parents learned how to manage the diet, which was considered the standard treatment for seizures for several decades.

When phenytoin (Dilantin) was introduced in 1938, doctors lost interest in the ketogenic diet to treat epilepsy. Patients found taking pills much easier than following such a restrictive eating pattern. Medications worked well enough for many individuals with epilepsy.

After decades of neglect, however, the ketogenic diet is returning to popularity. Some individuals don’t respond well to anti-seizure drugs. As a consequence, neurologists have once again begun to treat youngsters with refractory epilepsy by prescribing a low-carb high-fat ketogenic diet (Current Pharmaceutical Design, online Aug. 9, 2017).

An article in the journal Medicine, Sept. 26, 2025 sums up the benefits of the ketogenic diet (KD) this way:

“Since the 1920s, the KD has been considered a possible treatment for epilepsy. However, it has been put on hold for a significant period due to the extensive development and use of antiepileptic medications (ASMs) in clinical practice. In the past 2 decades, subsequent to continuous clinical research and basic experiments confirming the efficacy of KD in treating epilepsy (RE), KD has gained recognition as a treatment for RE [refractory epilepsy].”

The authors note that a ketogenic diet has an “efficacy rate ranging from 35% to 85% in patients with drug-resistant epilepsy.”

The article concludes:

“Based on the data obtained, it can be concluded that KD is a safe and effective treatment option for refractory epilepsy.”

Other Possible Uses for a Ketogenic Diet:

We recently received this question from a reader who made no reference to epilepsy: “Can you enlighten us about the ketogenic diet, which I suspect I need?” In recent years, physicians have adopted a carbohydrate-restricted diet to treat metabolic syndrome, type 2 diabetes and cardiovascular disease. The most recent research suggests that people with major mental health challenges such as depression and schizophrenia or bipolar disorder may also benefit.

Major Depressive Disorder:

A small pilot study published in the journal Translational Psychiatry (Sept. 20, 2025) offers some intriguing results. The investigators recruited Ohio State Students who had been diagnosed with major depressive disorder (MDD). They were getting either counseling or were on medications or both. All the volunteers were put on a ketogenic diet for 10 to 12 weeks. In other words, they limited their carbohydrate intake and got most of their calories in the forms of protein and fat (olive oil, fatty fish, nuts, etc).

The researchers verified that the students were following the ketogenic diet by having students regularly measure ketones and blood sugar levels. There was a dramatic reduction in depression scores by both clinicians and the students themselves.

Here are the results of this pilot study:

“Depressive symptoms decreased by 69% (PHQ-9 [Patient Health Questionnaire]) and 71% (HRSD [Hamilton Rating Scale for Depression]) post-intervention (p < 0.001), with improvement occurring within 2–6 weeks. Global well-being increased nearly 3-fold (p < 0.001). Participants lost body mass (−6.2%; p = 0.002) and fat mass (−13.0%; p < 0.001)…Performance improved on several cognitive tasks. In students with mild to moderate depression based on PHQ-9 and HRSD, implementation of a WFKD [well formulated ketogenic diet] for 10–12 weeks is a feasible adjunctive therapy and may be associated with improvements in depression symptoms, well-being, body composition, and cognition.”

These results are impressive. Medications do not often produce such good outcomes and they can cause some serious side effects.

Other Psychiatric Conditions (Schizophrenia):

Doctors usually rely on psychotropic drugs to treat people with bipolar disorder or schizophrenia. Such drugs can be helpful, but they come with a number of potential side effects. A study published in Psychiatry Research suggests that a ketogenic diet might be surprisingly helpful (Psychiatry Research, March 20, 2024).

The pilot study included just 23 individuals with schizophrenia or bipolar disorder along with metabolic abnormalities. There was no control group. After four months, people who stuck with the diet had lost weight and belly fat. Most importantly, their mental health had improved as measured by standardized rating scales. They also reported better sleep and increased life satisfaction.

Such a pilot study is inadequate on its own, but it suggests further trials should be done to explore diet as an additional means for treating mental illness. The scientists are recommending that the diet be tested as an ” adjunct” to rather than replacement for standard antipsychotic medications.

Diabetes:

Researchers have found that cutting carbohydrate intake dramatically reliably lowers blood sugar in people with type 2 diabetes (Nutrition, Jan. 2015). A year-long study of 115 overweight people with diabetes compared the effects of low-carb and high-carb diets (American Journal of Clinical Nutrition, Oct. 2015). The patients following a low-carb diet high in unsaturated fat were able to reduce their medications for blood glucose control. Their blood sugar was less variable, and their lipid profiles, especially HDL and triglycerides, were more favorable. Both groups lost weight and reduced their HbA1c (a measure of blood sugar control over time).

Weight Loss:

Studies in humans and experimental animals show that a very low-carb high-fat diet can help with weight loss (Nutrients, May 2017).  In one study, the weight loss drug orlistat (Xenical or Alli) combined with a low-fat diet was compared to a low-carbohydrate ketogenic diet ( Archives of Internal Medicine, Jan. 25, 2010).  Over the course of almost a year, both groups lost weight. Those following the ketogenic diet conscientiously improved their blood pressure, blood glucose and insulin levels more effectively.

Athletic Recovery:

Could a very low-carbohydrate diet improve athletic performance? That hypothesis was tested in a case study of five New Zealand endurance athletes (Journal of the International Society of Sports Nutrition, July 12, 2017). After ten weeks on the diet, their performance actually dropped somewhat. However, they reported feeling better, with improvements in recovery time, skin conditions and other inflammatory complaints.

In summary, a low-carbohydrate high-fat diet with adequate protein appears to be a reasonable approach for people who are attempting to lose weight, control their blood sugar and improve their fat metabolism. You’ll find information on how to follow such a diet in the book KetoClarity by Jimmy Moore and Dr. Eric Westman.

If you would like to listen to Dr. Eric Westman describe this eating approach and its potential benefits, here is a recent interview/podcast:

Show 1444: The Food Fight Over Fat: Keto and Carnivore Diets
The Mediterranean eating pattern has dominated dietary recommendations for years. Are there benefits to keto or carnivore diets?

Be sure to ask your doctor if this regimen is safe for you.

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