Ketogenic diet boosts mental health: Study reveals reduced stress and improved mood

Study: Ketogenic diet has a positive association with mental and emotional well-being in the general population. Image Credit: Chinnapong

Background 

The ketogenic diet, high in fats and low in carbohydrates, shifts metabolism from glycolysis to fatty acid oxidation, providing alternative energy substrates for the body and brain. Historically used to treat epilepsy and explored in neurodegenerative and neurodevelopmental conditions, its effects on the general population are less studied. Further research is needed to clearly understand the long-term psychological impacts of the ketogenic diet across diverse populations and conditions.

About the study 

The present study involved two cohorts, each recruited through opportunity sampling on social media platforms, adhering to ethical standards set by Northumbria University and the Declaration of Helsinki. All participants provided informed consent before data collection began.

In cohort 1, individuals were recruited from February to October 2021. Participants in this group completed two assessment tools online: the Perceived Stress Scale (PSS-10) and the Bond-Lader visual analog scales (BL-VAS). The PSS-10 assessed general perceptions of stress, with scores from 0 to 40, reflecting varying stress levels. The BL-VAS measured mood through 16 opposing mood pairs, providing scores on alertness, contentedness, and calmness, using a sliding scale from 0 to 100.

Cohort 2 was assembled from January to July 2022 and used different tools for psychological assessment: the Depression Anxiety Stress Scale (DASS-21) and a 3-item loneliness scale. The DASS-21 includes three subscales for depression, anxiety, and stress, each scored on a severity scale from 0 to 3. The loneliness scale, rated from 1 to 3, helped identify levels of loneliness among participants.

Both cohorts used an online platform to share the same demographic, socioeconomic, and dietary data collection methods. Participants reported on a range of variables, including dietary habits assessed via a short-form food frequency questionnaire. This enabled the comparison of dietary patterns between those on ketogenic diets and other diets, factoring in the frequency of consumption of ketogenic-friendly and non-ketogenic food items. The data were analyzed for various psychological and dietary metrics, examining differences and correlations within and between the groups. 

Study results 

In the study, cohort 1 initially recruited 361 participants, though exclusions were made for various reasons, including lack of consent and incomplete data entries, resulting in 260 participants completing the PSS-10. A further reduction occurred during the transition between survey platforms, leaving 147 participants who completed the BL-VAS. This cohort examined the perceived stress and mood variations between those on a ketogenic diet and those on other diets. 

Cohort 2 began with 399 participants and was reduced to 276 after similar exclusions. This cohort utilized the DASS-21 and a 3-item loneliness scale to evaluate psychological well-being.

In terms of demographics and socioeconomic factors, Cohort 1 displayed significant age and Body Mass Index (BMI) differences between the ketogenic and other diet groups. The ketogenic participants were generally older and had a higher BMI. Notable findings included higher instances of high blood pressure among ketogenic diet participants. Dietary patterns revealed that those on the ketogenic diet consumed "ketogenic-friendly" foods more frequently and "non-ketogenic" foods less frequently than their counterparts.

Cohort 2 showed similar age and health distinctions, with ketogenic participants again being older but with no significant differences in BMI between the groups. Health ratings and dietary habits followed similar patterns to Cohort 1, with ketogenic participants reporting better subjective health and adhering more strictly to ketogenic food guidelines.

Psychologically, Cohort 1 findings indicated that participants on a ketogenic diet reported better mood and lower stress levels than those not on the diet, with significant differences in alertness, contentedness, and calmness. These differences persisted even when adjusting for demographic and health-related covariates.

Cohort 2 also found that participants on a ketogenic diet reported lower levels of depression, anxiety, stress, and loneliness. However, the improvements in loneliness were not statistically significant when adjusting for covariates.

Additionally, the length of adherence to the ketogenic diet showed positive correlations with psychological benefits in both cohorts. However, the actual level of ketosis measured did not significantly correlate with psychological outcomes, suggesting that the duration of dietary consistency might be more influential than the immediate metabolic state.

Conclusions 

To summarize, the study hypothesized that a ketogenic diet would enhance psychological well-being, which was supported by the findings. Participants on the diet reported significantly better calmness, contentedness, alertness and reduced stress, depression, and anxiety. Although loneliness improvements were insignificant after adjusting for demographics, the diet's length correlated with increased benefits. Furthermore, the study suggests that a ketogenic diet may improve mental health by mechanisms similar to anxiety medications.

Journal reference:

• Sarah Garner, Evan Davies, Emma Barkus, Ann-Katrin Kraeuter, Ketogenic diet has a positive association with mental and emotional well-being in the general population, Nutrition (2024), DOI - 10.1016/j.nut.2024.112420, https://www.sciencedirect.com/science/article/pii/S0899900724000704