Ketogenic Diets Show Associations With Mental Health Changes

How a strict low carb pattern may influence depression and anxiety

Early research suggests ketogenic eating patterns may modestly improve depressive symptoms for some adults, while effects on anxiety remain uncertain and longer term evidence is still developing.

A major systematic review and meta analysis of 50 human studies involving more than 41,000 adults found that ketogenic diets may be associated with modest improvements in depressive symptoms in randomized trials, particularly when ketosis is verified and the carbohydrate restriction is very strict. Evidence for anxiety is mixed: randomized trials did not show clear benefits, although some nonrandomized studies reported improvement. These findings are promising but not definitive and should not be interpreted as a universal or causal effect.

Study details

This review brought together 50 human studies from 15 countries, focusing on adults aged 18 to 70 who followed a ketogenic or very low carbohydrate eating pattern. These diets required carbohydrate intake of less than about 50 grams per day or less than 26 percent of total calories, shifting the body into nutritional ketosis.

Participants came from a mixture of psychiatric and nonpsychiatric populations. Some had major depressive disorder, bipolar disorder, schizophrenia or post traumatic stress disorder. Others were adults with metabolic or neurological conditions where mood symptoms were monitored alongside changes in health.

Across the studies, mental health outcomes were measured using validated tools such as the PHQ 9 for depression or GAD 7 for anxiety. The goal was to understand whether ketogenic eating patterns were linked to changes in mood or anxiety over time, and how these effects compared with other diets.

Methodology

Researchers searched MEDLINE, Embase and APA PsycINFO and included only peer reviewed human studies that met strict criteria for carbohydrate restriction and used validated psychiatric scales. Both randomized clinical trials and quasi experimental studies were included.

The team analyzed changes in depressive and anxiety symptoms across studies. In randomized trials, they compared ketogenic diets with control diets. In nonrandomized studies, they measured changes within individuals before and after adopting a ketogenic pattern. Random effects models were used to account for differences across study designs, populations and diet protocols.

The analysis also explored whether ketosis verification, diet strictness, obesity status or comparison diet influenced results.

Key findings

Depression
• Ketogenic diets were associated with small to moderate improvements in depressive symptoms in randomized trials.
• Larger improvements were seen when ketosis was verified and when diets were very low in carbohydrates.
• Nonobese participants tended to show stronger improvements than participants with obesity.
• Comparisons with high carbohydrate control diets showed smaller differences.

Anxiety
• Randomized trials did not show a significant benefit for anxiety.
• Some nonrandomized studies reported improvements, but without control groups these results are harder to interpret.

Implications for practice

For individuals living with depression or anxiety

This review suggests ketogenic diets may offer modest support for lowering depressive symptoms in some adults, but they are not a universal treatment and are not proven to improve anxiety in randomized studies. Entering and maintaining ketosis is difficult, and the diet requires significant structure, planning and support. People with certain medical conditions or specific medications especially SGLT2 inhibitors may be at risk for complications.

Anyone considering a ketogenic diet for mood should work closely with a clinician or dietitian. These diets should be treated as a potential adjunct to standard therapy rather than a replacement for established treatments such as psychotherapy, antidepressant medications or balanced lifestyle interventions. Safety, sustainability and overall well being should guide decision making.

For clinicians and healthcare providers

The findings support cautious, evidence informed discussions with patients who express interest in ketogenic diets for mood. The strongest signal in the review was for depressive symptoms, particularly when biochemical ketosis was verified. Anxiety results were far less consistent.

Clinicians should screen for contraindications, provide structured guidance, emphasize monitoring and reinforce that ketogenic diets are not substitutes for standard psychiatric care. The metabolic phenotype of patients may matter, as individuals with obesity or insulin resistance may have more difficulty achieving ketosis. Longer term randomized trials with standardized protocols are needed before ketogenic diets can be broadly recommended in psychiatric practice.