Guest Post: The Science Behind the Ketogenic Diet

The ketogenic diet, nicknamed “keto”, has gained recent momentum throughout social media. Over 15 million posts on Instagram alone include the use of #keto. The diet has been praised by countless celebrities throughout social media for its many successes. Kim Kardashian, Megan Fox, and Vanessa Hudgens have all vouched for the diet’s positive effect on weight loss. Although they cannot be given credit for kicking off the trend, they have definitely contributed to its popularity. So, how did the diet get its start, and is it really worth all the hype?


The ketogenic was originally used in the 1920s as a treatment for difficult to treat childhood epilepsy (1). This is due to the capabilities of the ketogenic diet to mimic the state of fasting, which was the standard treatment at the time (1). The diet later became common for weight loss and has since been further used to treat several pathological conditions (2). Extensive research on the diet has displayed beneficial results for epilepsy, cardiovascular disease, and type 2 diabetes (2). It has been found to improve blood sugar levels and glucose sensitivity in the short-term (2). Where the research does lack is in long-term effects. This could be in part due to the restrictive nature of the diet, making it difficult to maintain. 

What is the ketogenic diet?

This diet comprises of the consumption of foods high in fat, and very low in carbohydrates. Typically speaking, while on the ketogenic diet 75% of your daily calories are obtained from fat, 20% from protein, and 5% from carbohydrates (3). The ultimate goal of the ketogenic diet is for the body to burn fat instead of carbohydrates.

Ketosis - What’s going on inside the body?

When carbohydrates are consumed, glucose - a simple sugar - is the primary energy source for most cells (4). So, what happens when you are not consuming enough glucose? You must get energy in a different way! Luckily, the body has different ways of creating energy (4). During low glucose availability, your body enters into a metabolic state called ketosis, which allows you to burn fat for energy (4). Fat is transported to the liver, where it is converted into molecules called ketone bodies (5). These molecules can then be used as energy (5). The time it takes for the body to enter into ketosis varies depending on several factors. On average, it takes the body 2 to 4 days. 

Weight loss

There is strong evidence that the ketogenic diet is effective for losing weight (2).  Individuals often experience the most weight loss 3 to 6 months after entering ketosis (6). However, the mechanism by which this occurs is not completely understood. It has been proposed that the ketogenic diet reduces hunger because proteins and ketone bodies keep you full for longer (2).  In addition, some carbohydrates are responsible for promoting hunger and cravings. During low-carbohydrate diets, weight loss can be promoted because of significant reductions in these hunger-stimulators (7). Again, due to the lack of long-term research, the effects on the body from following the ketogenic diet over an extended period of time are unknown. 

Final Thoughts

The ketogenic diet has been used for decades to tackle health issues ranging from epilepsy to weight loss. Yet, the diet remains controversial because there are still questions regarding its scientific nature and long-term risks. A medical professional should be consulted when considering the ketogenic diet because it might not be suitable for everyone. Genetic and environmental factors, as well as your current health status, will determine the effectiveness of this dietary regimen. 


Alexis and Cassandra are third-year students in the Integrated Science program at Western University pursuing Honor Specializations in genetics and biology. They are passionate about health, nutrition, and being active.


1 - Wheless, J. (2008). History of the ketogenic diet. (Report). Epilepsia, 49(s8), 3–5.

2 - Paoli, A., Rubini, A., Volek, J., & Grimaldi, K. (2013). Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. (Report). European Journal of Clinical Nutrition, 67(8), 789–78996.

3 - Freeman, J., Kossoff, E., & Hartman, A. (2007). The ketogenic diet: one decade later. (Clinical report). Pediatrics, 119(3), 535–53543.

4 - Masood, W., & Uppaluri K.R. (2019). Ketogenic Diet. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.

5 - Pratt, C. W., & Cornely, K. (2018). Essential Biochemistry (4th ed.). Hoboken, NJ: John Wiley & Sons, Inc.

6 - Sumithran, P., & Proietto, J. (2008). Ketogenic diets for weight loss: A review of their principles, safety and efficacy. Obesity Research & Clinical Practice, 2(1), 1–13.

7 - Erlanson-Albertsson, C., & Mei, J. (2005). The effect of low carbohydrate on energy metabolism. (New Insights and Consequences2005 European Childhood Obesity Group (ECOG) International Workshop)(Paper). International Journal of Obesity, 29(S2), S26–30.

  • Instagram
  • Facebook
  • YouTube
  • Pinterest
  • Twitter

Stay up to date by signing up for my newsletter here

Copyright © 2020 Simply Nic Nutrition | | St. Thomas, Ontario, Canada