The ketogenic diet, commonly known as the keto diet, has gained significant attention in recent years for its potential benefits in weight management and various health conditions. This high-fat, low-carbohydrate diet aims to induce a metabolic state called ketosis, where the body relies on ketone bodies derived from fat as its primary energy source instead of glucose from carbohydrates. While the keto diet has shown promise in several areas, it is essential to understand its mechanisms, benefits, and potential risks.
Benefits attributed to it include:
- Promotes weight loss Attaye et al., 2021
- Increases insulin sensitivity Attaye et al., 2021
- Reduces dyslipidaemia Attaye et al., 2021
- Improves mood and reduces symptoms of neurodegenerative and neurodevelopmental disorders [Garner et al., 2024]
- Associated with higher self-reported mental and emotional well-being behaviours, including calmness, contentedness, alertness, cognitive and emotional stress, depression, anxiety, and loneliness Garner et al., 2024
- Reduces seizure frequency Crosby et al., 2021
Mechanisms of the Ketogenic Diet
The primary goal of the ketogenic diet is to shift the body’s metabolism from glucose to ketones. This metabolic state, known as ketosis, is achieved by drastically reducing carbohydrate intake to less than 50 grams per day and increasing fat consumption to about 75% of daily caloric intake, with the remaining 20% from protein. In ketosis, the liver converts fatty acids into ketone bodies, which serve as an alternative energy source for the brain and other tissues. Several mechanisms underlie the therapeutic effects of the ketogenic diet. One key mechanism is the inhibition of histone deacetylases (HDACs) by β-hydroxybutyrate (BHB), a primary ketone body. HDAC inhibition can alter gene expression and reduce inflammation, potentially benefiting conditions like epilepsy and neurodegenerative diseases[1],[2]. Additionally, the ketogenic diet improves mitochondrial function, enhances bioenergetic reserves, and modulates neurotransmitter systems, contributing to its neuroprotective effects[3].
Weight Loss and Metabolic Health
One of the most well-known benefits of the ketogenic diet is its potential for weight loss[4]. By reducing carbohydrate intake, the body depletes glycogen stores and begins to burn fat for energy, leading to weight loss. Studies have shown that the keto diet can be more effective for short-term weight loss compared to low-fat diets. Additionally, ketosis can suppress appetite, further aiding in weight management. The ketogenic diet has also shown promise in improving metabolic health. It can enhance insulin sensitivity and lower blood glucose levels, making it a potential therapeutic option for individuals with type 2 diabetes. Some studies suggest that the diet can improve lipid profiles by increasing high-density lipoprotein (HDL) and reducing triglycerides, although its impact on low-density lipoprotein (LDL) cholesterol remains controversial[5].
Neurological and Epileptic Conditions
The ketogenic diet has a long history of use in managing epilepsy, particularly in children with drug-resistant epilepsy. It can significantly reduce seizure frequency and, in some cases, eliminate the need for medication. The diet’s neuroprotective effects are attributed to its ability to stabilise neuronal membranes, enhance GABAergic neurotransmission, and reduce neuroinflammation[6]. A recent paper published in Psychiatry Research in May 2024 found that over a 4 month period pilot trial it offered specific benefits for metabolic health and psychiatric health in Bipolar and Schizophrenic patients[7]. Mental health and physical health are interconnected, and addressing metabolic issues via specific nutritional strategies can complement psychiatric treatment to enhance overall well-being. Understanding the mechanisms and potential synergies between psychiatric treatment and metabolic improvements can also inform the development of more effective interventions.
Other Potential Benefits
Emerging research suggests that the ketogenic diet may have therapeutic potential in other conditions, such as cancer, Alzheimer’s disease, and polycystic ovary syndrome (PCOS). The diet’s ability to alter the metabolic environment of cancer cells and reduce insulin levels may inhibit cancer growth[8]. In Alzheimer’s disease, the ketogenic diet may improve cognitive function by providing an alternative energy source for the brain and reducing amyloid-beta accumulation[9].
Risks and Considerations
Despite its potential benefits, the ketogenic diet is not without risks. One of the primary concerns is its high saturated fat content, which can increase LDL cholesterol levels and potentially raise the risk of heart disease. It is crucial to focus on healthy fat sources, such as avocados, nuts, and olive oil, to mitigate this risk[10].
Nutrient Deficiencies
The restrictive nature of the ketogenic diet can lead to nutrient deficiencies. By limiting fruits, vegetables, and whole grains, individuals may not get enough essential vitamins and minerals, such as magnesium, potassium, and vitamins B (folate and B12) A and C[11]. This can result in symptoms like fatigue, muscle cramps, and weakened immune function.
Kidney and Liver Issues
The high protein and fat intake in the ketogenic diet can strain the kidneys and liver. Individuals with pre-existing kidney conditions may be at risk of developing kidney stones due to increased calcium excretion in the urine[12]. Additionally, the liver’s increased workload in metabolizing fat can exacerbate existing liver conditions. However, while there are some concerns about liver damage and injury related to the ketogenic diet, most of the evidence suggests that the diet may either improve liver function or have neutral effects. More research is needed to fully understand the relationship between the ketogenic diet and liver function.
Gastrointestinal Issues
The low fibre content of the ketogenic diet can lead to constipation and other gastrointestinal issues. Fibre is essential for maintaining healthy gut bacteria and promoting regular bowel movements. To counteract this, individuals should include low-carb, high-fibre vegetables in their diet.
Keto Flu and Long-term Sustainability
Many individuals experience “keto flu” during the initial stages of the diet, characterized by symptoms like headache, fatigue, nausea, and irritability[13]. These symptoms are typically temporary and result from the body’s adaptation to ketosis. However, the stringent food restrictions make the ketogenic diet challenging to sustain long-term, leading to potential yo-yo dieting and weight regain.
Several key supplements are often recommended for individuals following a ketogenic diet. These supplements can help address potential nutrient deficiencies, support the body’s adaptation to ketosis, and enhance overall health while on the diet.
7 key supplements to consider:
- Electrolytes: Electrolyte supplements are crucial for those on a ketogenic diet, particularly during the initial transition phase. When carbohydrate intake is drastically reduced, the body excretes more water and electrolytes. Supplementing with sodium, potassium, and magnesium can help prevent electrolyte imbalances and alleviate symptoms like muscle cramps, dizziness, and fatigue.
- Magnesium: Magnesium is specifically highlighted as an important supplement for keto dieters. Many magnesium-rich foods are high in carbs and thus limited on a keto diet. Supplementing with magnesium can help reduce muscle cramps, insomnia, and irritability, which are common symptoms during the transition to ketosis.
- MCT Oil: Medium-chain triglyceride (MCT) oil is a popular supplement among keto dieters. MCTs are rapidly absorbed and converted into ketones by the liver, providing quick energy and potentially helping to maintain ketosis. MCT oil can be added to shakes or taken directly to increase fat intake and boost ketone levels.
- Omega-3 Fatty Acids: Fish oil or krill oil supplements rich in omega-3 fatty acids (EPA and DHA) are beneficial for those on a ketogenic diet. These supplements can help balance the omega-6 to omega-3 ratio, reduce inflammation, and support heart and brain health.
- Vitamin D: Vitamin D is mentioned as one of the best keto supplements as it is important for overall health, and supplementation may be necessary, especially if sun exposure is limited.
- Digestive Enzymes: Digestive enzyme supplements can help the body better process the increased fat intake typical of a ketogenic diet.
- Multivitamins: A high-quality multivitamin can help ensure adequate intake of essential nutrients that may be lacking in a restricted ketogenic diet.
Conclusion
The ketogenic diet offers a unique approach to health management, with potential benefits in weight loss, metabolic health, and neurological conditions. However, it is essential to approach the diet with caution and under careful supervision due to its associated risks. Individuals considering the ketogenic diet should consult with healthcare professionals to ensure it is appropriate for their specific health needs and to develop a balanced, nutrient-dense meal plan. As research continues to evolve, a more comprehensive understanding of the ketogenic diet’s long-term effects and optimal applications will emerge, guiding its use in health management.
References
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[2] Jiang Z, Yin X, Wang M, Chen T, Wang Y, Gao Z, Wang Z. Effects of Ketogenic Diet on Neuroinflammation in Neurodegenerative Diseases. Aging Dis. 2022 Jul 11;13(4):1146-1165
[3] Paoli A, Cerullo G. Investigating the Link between Ketogenic Diet, NAFLD, Mitochondria, and Oxidative Stress: A Narrative Review. Antioxidants (Basel). 2023 May 8;12(5):1065
[4] Murphy EA, Jenkins TJ. A ketogenic diet for reducing obesity and maintaining capacity for physical activity: hype or hope? Curr Opin Clin Nutr Metab Care. 2019 Jul;22(4):314-319
[5] Shahpasand S, Khatami SH, Ehtiati S, Alehossein P, Salmani F, Toutounchi AH, Zarei T, Shahmohammadi MR, Khodarahmi R, Aghamollaii V, Tafakhori A, Karima S. Therapeutic Potential of the Ketogenic Diet: A Metabolic Switch with Implications for Neurological Disorders, the Gut-Brain Axis, and Cardiovascular Diseases. J Nutr Biochem. 2024 Jun 14:109693
[6] Rudy L, Carmen R, Daniel R, Artemio R, Moisés RO. Anticonvulsant mechanisms of the ketogenic diet and caloric restriction. Epilepsy Res. 2020 Dec;168:106499
[7] Sethi S, Wakeham D, Ketter T, Hooshmand F, Bjornstad J, Richards B, Westman E, Krauss RM, Saslow L. Ketogenic Diet Intervention on Metabolic and Psychiatric Health in Bipolar and Schizophrenia: A Pilot Trial. Psychiatry Res. 2024 May;335:115866.
[8] Mercier BD, Tizpa E, Philip EJ, Feng Q, Huang Z, Thomas RM, Pal SK, Dorff TB, Li YR. Dietary Interventions in Cancer Treatment and Response: A Comprehensive Review. Cancers (Basel). 2022 Oct 20;14(20):5149
[9] Hansen B, Roomp K, Ebid H, Schneider JG. Perspective: The Impact of Fasting and Caloric Restriction on Neurodegenerative Diseases in Humans. Adv Nutr. 2024 Apr;15(4):100197
[10] Meng Y, Sun J, Zhang G. Take the bull by the horns and tackle the potential downsides of the ketogenic diet. Nutrition. 2024 May 2;125:112480
[11] Ruiz Herrero J, Cañedo Villarroya E, García Peñas JJ, García Alcolea B, Gómez Fernández B, Puerta Macfarland LA, Pedrón-Giner C. Terapias dietéticas cetogénicas en epilepsia: experiencia en 160 pacientes durante 18 años [Ketogenic dietary therapies for epilepsy: Experience in 160 patients over 18 years]. An Pediatr (Engl Ed). 2021 Jun 14:S1695-4033(21)00193-4
[12] Ayele GM, Atalay RT, Mamo RT, Hussien S, Nigussie B, Fissha A, Michael MB. Is Losing Weight Worth Losing Your Kidney: Keto Diet Resulting in Renal Failure. Cureus. 2023 Mar 22;15(3):e36546.
[13] Bostock ECS, Kirkby KC, Taylor BV, Hawrelak JA. Consumer Reports of “Keto Flu” Associated With the Ketogenic Diet. Front Nutr. 2020 Mar 13;7:20
