Study Links Ketogenic Diet to Reduced Depression Symptoms in College Students

A recent study indicates that adhering to a well-structured ketogenic diet for a minimum of 10 weeks can significantly alleviate symptoms of depression in a small group of college students. Published in Translational Psychiatry, the research also highlighted improvements in general well-being and cognitive performance among participants.

This investigation was inspired by the rising rates of major depression, particularly in college environments. Current conventional treatments, like medication and therapy, tend to work for many but not for all, and sometimes they come with unwanted side effects. A team led by Drew D. Decker from The Ohio State University aimed to look into a different method, which considers the relationship between metabolic health and depression.

Evidence is accumulating that links problems such as insulin resistance and excess body fat to a heightened risk of depression, possibly because of inflammatory processes. The researchers hypothesized that a dietary approach known for enhancing metabolic health—the very low-carbohydrate ketogenic diet—could be a useful supplementary therapy for students already receiving standard treatments for depression.

The study took shape as a single-arm prospective trial, meaning all participants were given the same dietary regimen without a control group for comparison. Students diagnosed with Major Depressive Disorder who were seeking counseling or taking medication were recruited from The Ohio State University. After a thorough screening process to exclude conditions like eating disorders, 24 students began, though only 16 completed the full 10 to 12-week program.

“We wanted to ensure that our treatment was tailored for participants who met the criteria for major depressive disorder,” explained Jennifer Cheavens, a co-author and clinical psychology professor at Ohio State. “Each person underwent a lengthy interview at the outset and continued symptom assessments weekly.”

Before starting the diet, participants attended a comprehensive informational session. The well-structured ketogenic diet required limiting carbohydrate intake to under 50 grams per day, eating a moderate amount of protein, and obtaining the rest of their caloric intake from fats—favoring whole food sources like olive oil, nuts, and fatty fish. To aid compliance and manage costs, the research team provided essential ketogenic foods and consistent support via dietitians through a messaging platform.

“It was crucial for participants to grasp what they were signing up for,” said Drew Decker, the paper’s first author. “A big part of ensuring adherence was discussing food preferences with individuals so we could tailor suggestions for their diets.”

Throughout the study, various outcomes were monitored. Participants reported their depressive symptoms bi-weekly using the Patient Health Questionnaire-9, while a qualified clinician assessed their depression using the Hamilton Rating Scale at the beginning, mid-point, and conclusion of the study. To confirm dietary adherence, students tracked their morning blood ketone and glucose levels daily. Additionally, body composition was assessed through scans, blood samples were collected for metabolic and inflammatory markers, and cognitive tests were administered on iPads.

The results revealed a significant and sustained decrease in depression symptoms. Among the 16 students who completed the program, self-reported depression scores dropped by an average of 69% from start to finish. Clinician ratings mirrored this trend with a 71% reduction. Notably, every participant who completed the study showed improvement, and by the end, none met the criteria for moderate or severe depression.

Ryan Patel, a psychiatrist at Ohio State involved in the study, emphasized the importance of these findings. “The typical effect size for medications and counseling after 12 weeks is around 50%, so seeing such a larger result is impressive,” he stated. “It’s remarkable that in this realistic setting, everyone improved, and participants didn’t require more treatment or emergency help.”

In addition to mental health benefits, participants also experienced physical changes. Fifteen out of the 16 students lost a clinically significant amount of weight, averaging around 5 kilograms, or about 11 pounds, primarily from body fat. Blood tests showed a 32% increase in brain-derived neurotrophic factor—a protein essential for neuron health—and a 52% decrease in leptin, which is related to body fat and appetite.

Cognitive function also improved; participants made significant gains in tests of episodic memory, processing speed, and executive function. They could recall more words from lists and complete symbol-matching tasks faster by the end of the study compared to the beginning. Their self-reported sense of global well-being increased almost threefold throughout the intervention.

The researchers investigated whether the improvements in depression stemmed solely from weight loss or the presence of ketones in the bloodstream. They found no significant correlation, suggesting that the diet’s positive impact on mood likely results from more complex biological changes beyond just weight loss.

“The ketogenic diet appears to influence mood through various potentially different mechanisms, amidst a range of physiological metabolic adaptations that could correlate with aspects of depression,” explained Jeff Volek, the study’s senior author and a human sciences professor at The Ohio State University.

The authors acknowledged several limitations of the study. The single-arm design makes it challenging to isolate the specific effects of the diet from the participants’ ongoing counseling and medication or the mere passage of time. Additionally, the small sample size and the fact that participants opted to join the diet study may skew results. Repeated cognitive testing may also improve scores due to familiarity, an effect that could not easily be removed without a control group.

Future studies are needed to verify these findings in larger, randomized controlled trials that can more definitively isolate the diet’s effects. Such investigations could also shed light on the biological mechanisms responsible for these observed benefits.

Despite these limitations, the findings present a hopeful avenue for new treatment possibilities. “We’re facing a treatment gap where many students suffer from mental health issues and cannot access professional support,” Patel noted. “Nutrition is one potential way to help students on a larger scale.”

Volek added that the research lays a strong groundwork for additional inquiry. “With so many people struggling right now, it feels rewarding to possibly present a solution,” he said. “This study is one of the first well-controlled ones; it has limitations, but the results push us to continue exploring this area.”