It's a small—but promising—look into how certain diet shifts could positively impact mental health.
What you eat doesn’t just shape your waistline—it may also influence how your brain works, feels, and adapts. Emerging research is shining a light on the powerful role diet plays in fueling the brain, particularly when the body shifts from running on sugar to running on fat. In a recent pilot study, researchers found that this metabolic switch was linked to dramatic improvements in mental and emotional functioning among young adults, raising fresh questions about whether changing the brain’s energy source could open new doors for supporting overall brain health.
The researchers behind the study—a group of psychology, psychiatry, and nutrition experts at The Ohio State University (OSU)—stress that the findings are preliminary, but say a ketogenic, or “keto,” diet may offer promise as an add-on approach for treating depression. This is especially significant given that a 2025 Gallup survey learned that an estimated 47.8 million Americans have depression, a number Gallup refers to as “historically high.”
A ketogenic diet drastically limits carbohydrates while emphasizing healthy fats and moderate protein. Harvard Health experts, emphasizing caution when considering this diet, explain: “Unlike other low-carb diets, which focus on protein, a keto plan centers on fat, which supplies as much as 90% of daily calories.” This shift pushes the body into “nutritional ketosis,” a state in which fats are broken down into ketones that serve as an alternative fuel source for the brain and body.
In the study, published in the journal Translational Psychiatry in September 2025, researchers followed 24 college students diagnosed with major depressive disorder who were asked to adopt a ketogenic diet for at least 10 weeks. Among the sixteen participants who completed the full study, they found that depression symptoms dropped by about 70% on average by the end of the intervention.
“So many people are suffering right now, so it’s rewarding to potentially bring forward a solution,” said lead researcher Jeff Volek, PhD, a professor of human sciences at OSU, in a news release. “There is more science yet to do, but because there is evidence of a benefit, expanding accessibility to a well-formulated ketogenic diet as an augmentation to treatment for depression is something to think about,” he added.
The participants—selected after a 2.5 hour mental health screening to confirm that they met the diagnostic criteria for having major depressive disorder—worked closely with the research team to tailor the diet to their food preferences in order to support long-term adherence. However, all study subjects were asked to limit their carb intake to less than 50 grams per day.
Ultimately, blood tests showed that students were in ketosis about 73% of the time. Over roughly three months, self-reported depression scores improved by 69%, while therapist-rated assessments improved by 71%.
Researchers noted that these improvements exceed the average 50% symptom reduction typically seen after 12 weeks of antidepressant medication or counseling. Participants also lost an average of 11 pounds, with no significant changes in cholesterol levels.
“That is an impressive finding, that across the board, in this real-world setting, everybody got better, and across the board, our participants did not need more treatment or emergency intervention,” said researcher Ryan Patel, DO, a psychiatrist at OSU’s Office of Student Life Counseling and Consultation Service.
Despite the encouraging results, the study lacked a comparison group and involved a small number of participants. Researchers say larger, controlled trials are essential to determine whether a ketogenic diet can reliably and safely support depression treatment.
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