Individuals adhering to ketogenic diet are less likely to suffer from depression

An analysis of U.S. National Health and Nutrition Examination Survey data from 2005 to 2023 found that individuals with higher adherence to the ketogenic diet were less likely to experience depression. Greater adherence to the diet was also linked to lower severity of depression symptoms. The findings were published in the Journal of Affective Disorders.

The ketogenic (or keto) diet is a low-carbohydrate, high-fat eating plan intended to shift the body into a state called ketosis, in which fat is burned for energy instead of carbohydrates. This diet typically includes meats, eggs, cheese, healthy fats, and low-carb vegetables, while avoiding bread, pasta, sugar, and most fruits.

Originally developed to treat epilepsy, the keto diet has gained popularity for weight loss and blood sugar control. Many followers report reduced appetite and improved mental focus. However, some people experience side effects—especially in the early stages—including fatigue and digestive discomfort, often referred to as the “keto flu.”

Study author Hao Ren and his colleagues sought to examine the relationship between adherence to the ketogenic diet and the risk of depression. They noted that previous research has linked frequent consumption of fried foods to a higher risk of depression, possibly due to acrylamide—a compound that forms during high-temperature frying.

Since fried foods are often consumed on a ketogenic diet, one might expect a higher depression risk among keto dieters. However, other characteristics of the diet may support brain function, including improved glucose metabolism, reduced neuroinflammation, and decreased oxidative stress, which could potentially lower depression risk.

The researchers analyzed data from the National Health and Nutrition Examination Survey, a program run by the Centers for Disease Control and Prevention. The survey uses a nationally representative sample to assess the health and nutritional status of the U.S. population through interviews, physical examinations, and dietary assessments.

This study included data from 28,995 participants surveyed between 2005 and 2023. Of these, 4,484 were classified as having depression. The average age of participants was 47 years, and 15,654 were women.

The researchers used information on depression diagnoses and symptoms, as measured by the Patient Health Questionnaire-9, along with data from two 24-hour dietary recall interviews. These interviews asked participants to report everything they had eaten and drunk in the previous 24 hours. The researchers then estimated how closely each individual’s diet aligned with the ketogenic diet.

The results indicated that the more a participant’s diet resembled a ketogenic pattern, the lower their risk of depression. The study also found that individuals who slept more than 10 hours per day, those who slept less than 6 hours, and individuals over the age of 40 were more likely to experience depression. Depression risk was also elevated among participants with serious health conditions such as angina, stroke, diabetes, or high cholesterol.

“As our analysis suggests, the observed relationship between KD [the ketogenic diet] and depression warrants further investigation into the effects of this dietary approach on mood disorders. Elucidating the potential mechanisms of KD on mood disorders is crucial for providing dietary recommendations for patients with these conditions,” the study authors concluded.

The study contributes to the scientific understanding of depression risk factors. However, it should be noted that the design of this study does not allow any causal inferences to be derived from the results. While it is possible that the ketogenic diet protects against depression, it is also possible that depressed individuals are less capable of taking care of their diet resulting, among other things, in lower adherence to the ketogenic diet.

The paper “Association between ketogenic diets and depression: A cross-sectional analysis of the NHANES 2005–2023 August” was authored by Hao Ren, Zhihao Wang, Yunbo Yuan, Yuze He, Wenhao Li, Yuhang Ou, Shuxin Zhang, Siliang Chen, Junhong Li, Yunhui Zeng, and Yanhui Liu.