The Keto diet may seem like a new phenomenon, but it was actually developed in the 1920’s as a treatment for epilepsy.


Originally, research was focused on the use of fasting as a treatment for epilepsy which demonstrated promising results at the time.


Whilst examining the mechanisms behind its effectiveness, it was noted that subjects on the fasting diet produced the chemicals acetone and beta-hydroxybutyric acid (ketones).


These same chemicals were also found to be produced in those on a low carb/high fat diet, so it was suggested that the benefits of fasting for epilepsy could still be obtained without having to fast, by using this high fat/low carb approach (as the ketones would still be produced)


Thus, the ketogenic diet was born.


Throughout the 20th century, the Keto diet started off being widely used as a treatment before alternative medications were discovered.


It then gained popularity again in the 1990’s due to media attention for its effective treatment of epilepsy in a young child.


Since then, there’s been a massive increase in scientific literature around the diet and its transcended medicine into nutrition as an intervention for fat loss.

What is it?

The keto diet is a very high fat, low carb diet that aims to induce a state of ketosis in the body.


Ketosis is kind of your bodies back up system for energy when glucose (the basic form of carbohydrates) runs out.


The amount of fat in the diet may vary slightly, with original implementations of the diet using 90% fat and a split of 10% between protein and carbs. Kossof et al (2019)


For its modern day non-medical use, the keto diet tends to float around 75% fat, 5% carbs and 20% protein (give or take)

How It Works

During ketosis, chemicals called ketone bodies are produced by the liver through the breakdown of fats, which work as an alternative source of energy to glucose.


Ketones are an effective alternative to glucose as they can cross the blood brain barrier to be used for energy by the brain (which is quite important).


Interestingly, research into epilepsy suggests that it is the interaction between glucose and the brain which causes seizures. Mcdonald et al (2018)


Hence why the keto diet is effective for reducing epileptic seizures.


The keto diet claims that by limiting carbohydrates and mostly consuming fats, you will eventually become fat adapted, and your body will become a fat burning machine.


Sounds great right?

Does Keto Work?

While you will no doubt see an initial drop in weight on the Keto diet, this isn’t reflective of the diet’s effectiveness.


An initial weight drop is attributed to the depletion of your body’s glycogen stores (stored form of carbohydrate), in response to your restriction of dietary carbohydrates.


Since for every 1g of carbohydrate stored, 2-3g of water is retained, the initial weight loss is due to the loss of both glycogen and water from the body.


This initial drop can entice people into the diet as this pretty fast acting mechanism induces buy-in.


However, if you actually want to lose fat then we need to look a little deeper.

Will You Become a Fat Burning Machine?

Well, here’s the truth.


You do burn more fat on the keto diet.


I said it.


Want to know why?


Well, because if you’re consuming a diet high in fat and low in everything else, how can you be burning anything else but fat?


The fat that you burn on the keto diet, is dietary fat.


To burn through you stored fat, then you will need to be in a calorie deficit (just like any other diet).

What Does the Research Say?

A 2006 study by Johnstone et al compared a ketogenic low carbohydrate diet (KLC) with a non-ketogenic low carbohydrate diet (NLC), to see the differences between weight loss and biomarkers.


The composition of the KLC diet was 60% Fat, 5% Carbs and 35% protein.


The composition of the NLC diet was 30% fat, 40% energy as carbs and 30% protein


Participants were physically inactive throughout; energy intake was strictly controlled, and all food and drink were provided for them.


The study concluded that no significant difference was found between the amount of weight loss in each group.


Furthermore, a statement by the National Lipid Association reviewing the current evidence and clinical recommendations on the effects of low-carbohydrate and very-low carbohydrate (including ketogenic) diets for the management of bodyweight and risk factors concluded that low-CHO and very-low-CHO are not superior to other dietary approaches for weight loss.


When energy balance is equated for, the keto diet is no more effective at burning fat than any other diet.

So Why Does it Work For People?

Well, apart from the initial drop in weight already clarified, the Keto diet does often create a calorie deficit required for fat loss.


If you’re eating in calorie deficit, but only eating fats, then yes, your body will burn fat and you will lose fat.


However, if you’re following the keto diet but eating to a calorie surplus, then you’ll still put on fat regardless.


 The keto diet often works for people because it:


  1. Gives them a system to follow
  2. Makes it hard to overconsume calories as fat is a very satiating macronutrient (therefore creating a calorie deficit)


In fact, the Keto diet has been shown prevent an increase in appetite in obese people, as they lose weight (Gibson et al, 2015).


Typically, during dieting, appetite will increase (less food = more desire for eat), but with the Keto diet it seems to be suppressed somewhat.


They’re many less decisions to be made when you know exactly what foods you can and can’t eat.


Having a system to follow can make it easier to adhere to for some, but the overarching restrictive elements of the Keto diet can make it hard to adhere to for others (who really wants to cut out bread?)


One thing is for sure, it’s far from sustainable.


Most people won’t be eating mostly fats for the rest of their lives, so what happens when the diet inevitably ends?


How will you reintroduce carbs and how will you address all the behavioural tendencies that led to your weight gain in the first place?


Even in the short term, it’s fair to suggest that aftercare on the diet is crucial to ensure that any fat loss is maintained.

My Opinion

The Keto diet has its merit as a medical intervention, but as a nutrition intervention for fat loss, the sacrifices that need to be made seem unnecessary and counterproductive for a vast majority of the population.


The general population can achieve the same weight loss on an energy restricted diet, without having to remove whole food groups.


By doing this, the general population can achieve weight loss with a wide variety of food sources and develop sustainable eating behaviours to keep weight off in the longer term.


Unless you have a medical condition in which Keto can help to improve and extend your life, I wouldn’t personally recommend it.

Want to Finally Lose Fat and Keep it Off?

Fed up of not seeing the results that you want? 
Then why not try Online Coaching with me and learn to build a Strong and Sustainable body, through tailored nutrition coaching and bespoke pain free exercise programming.

You can also learn more about online coaching here and nutrition coaching services here

Alternatively contact me here or leave a comment in the section below!



Gibson, A., Seimon, R., Lee, C., Ayre, J., Franklin, J., Markovic, T., Caterson, I. and Sainsbury, A., 2014. Do ketogenic diets really suppress appetite? A systematic review and meta-analysis. Obesity Reviews, 16(1), pp.64-76.


Johnston, C., Tjonn, S., Swan, P., White, A., Hutchins, H. and Sears, B., 2006. Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets. The American Journal of Clinical Nutrition, 83(5), pp.1055-1061.


Kirkpatrick, C., Bolick, J., Kris-Etherton, P., Sikand, G., Aspry, K., Soffer, D., Willard, K. and Maki, K., 2019. Review of current evidence and clinical recommendations on the effects of low-carbohydrate and very-low-carbohydrate (including ketogenic) diets for the management of body weight and other cardiometabolic risk factors: A scientific statement from the National Lipid Association Nutrition and Lifestyle Task Force. Journal of Clinical Lipidology, 13(5), pp.689-711.e1.


Kossoff EH, Zupec-Kania BA, Amark PE, Ballaban-Gil KR, Christina Bergqvist AG, Blackford R et al. Optimal clinical management of children receiving the ketogenic diet: recommendations of the International Ketogenic Diet Study Group. Epilepsia. 2009;50(2):304-17. doi:10.1111/j.1528-1167.2008.01765.x

McDonald, T., Puchowicz, M. and Borges, K., 2018. Impairments in Oxidative Glucose Metabolism in Epilepsy and Metabolic Treatments Thereof. Frontiers in Cellular Neuroscience, 12.


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Sam is a Personal Trainer, Online Coach and Fitness Educator with background in achieving results for a variety of clients. Sam now specialises in Pain Free Performance, helping people across the world to achieve their goals safely and effectively. 

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