The Keto Diet: Good or Bad?
What is the ketogenic (keto) diet?
The keto diet essentially consists of eating a high fat, moderate protein, and low carbohydrate diet. It had first gained popularity in the 1920s as a treatment option for drug-resistant epilepsy in individuals. Today, many individuals use it as a weight loss diet approach, or even as an approach to control type 2 diabetes (T2DM) (Sampaio, 2016).
How does the keto diet work?
By reducing your carbohydrates, your body essentially starts burning fat for energy which, in turn, starts producing ketones. This is the metabolic process called ketosis, which usually starts a few days after starting the keto diet. This is achieved by consuming foods high in fats and strictly limiting your carbohydrate intake to usually less than 50 or even 20 grams per day. Sources of carbohydrates can range from bread and grains to fruits and vegetables (Mayo Clinic, 2020).
Research showing the effect of the keto diet on weight loss, diabetes, cholesterol, and brain diseases:
Studies have shown that the keto diet is effective in quickly losing weight, even more effective than a low-fat diet. However, most studies have found that in the long term, the keto diet is not more effective than any other conventional weight loss diet (Bueno et al, 2013).
The keto diet has shown to improve blood sugar levels for type 2 diabetes temporarily. However, the long-term effects of a ketogenic diet in patients with diabetes is not yet clear. In terms of cholesterol levels, results are contradicting at the moment and no conclusion could be formed for the effect of the keto diet on cholesterol levels over a long period of time (Yuan, 2020).
As for brain diseases, the only robust research showing the benefits of the keto diet is relating to epilepsy. Other neurodegenerative diseases, such as Alzheimer’s disease, have yet to be extensively studied on human subjects(Grammatikopoulou et al, 2020).
Keto diet risks (short-term and long-term):
Symptoms at the beginning of adopting the keto diet can include fatigue, nausea, bad breath, vomiting and gastrointestinal disturbances (Sampaio, 2016). Over the long term, individuals might find it difficult to adhere to the diet since the recommendations can be very restricting. Another aspect to consider is that adopting this rigid lifestyle without proper adaptations can even risk vitamin or mineral deficiencies due to the limited variety of food consumed.
While this diet seems promising in terms of managing obesity and diabetes, it is important to keep in mind that the research is limited to the short term. The effect of restricting carbs long-term is unknown at the moment. On the other hand, it is always helpful to stick to things we do know, such as the overall health benefits of following a diet rich in fruits, vegetables and fiber (Sofi et al, 2008). Another aspect to not forget is the mental health impact diets can have on an individual. Overall, if you are planning on going on the keto diet, it is always a good idea to speak with a health specialist.
Bueno, N., De Melo, I., De Oliveira, S., & Da Rocha Ataide, T. (2013). Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: A meta-analysis of randomized controlled trials. British Journal of Nutrition, 110(7), 1178-1187. doi:10.1017/S0007114513000548
Maria G Grammatikopoulou, Dimitrios G Goulis, Konstantinos Gkiouras, Xenophon Theodoridis, Kalliopi K Gkouskou, Athanasios Evangeliou, Efthimis Dardiotis, Dimitrios P Bogdanos, To Keto or Not to Keto? A Systematic Review of Randomized Controlled Trials Assessing the Effects of Ketogenic Therapy on Alzheimer's Disease, Advances in Nutrition, Volume 11, Issue 6, November 2020, Pages 1583–1602, https://doi-org.proxy3.library.mcgill.ca/10.1093/advances/nmaa073
Marcelo Campos, M. D. (2020, April 14). Ketogenic diet: Is the ultimate low-carb diet good for you? Harvard Health. Retrieved January 17, 2022, from https://www.health.harvard.edu/blog/ketogenic-diet-is-the-ultimate-low-carb-diet-good-for-you-2017072712089
Mayo Foundation for Medical Education and Research. (2020, November 18). Can a low-carb diet help you lose weight?Mayo Clinic. Retrieved January 16, 2022, from https://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/low-carb-diet/art-20045831
Sampaio, L. P. (2016). Ketogenic diet for epilepsy treatment. Arquivos De Neuro-Psiquiatria, 74(10), 842–848. https://doi.org/10.1590/0004-282x20160116
Sofi F, Cesari F, Abbate R, Gensini GF, Casini A. Adherence to Mediterranean diet and health status: meta-analysis. BMJ. 2008 Sep 11;337:a1344. doi: 10.1136/bmj.a1344. PMID: 18786971; PMCID: PMC2533524.
Yuan, X., Wang, J., Yang, S. et al. Effect of the ketogenic diet on glycemic control, insulin resistance, and lipid metabolism in patients with T2DM: a systematic review and meta-analysis. Nutr. Diabetes 10, 38 (2020). https://doi-org.proxy3.library.mcgill.ca/10.1038/s41387-020-00142-z