Posted on 17 December, 2018

What Happens to Your Body on Ketosis?

By Jacob Andreae in Health, Lifestyle, Nutrition What Happens to Your Body on Ketosis?

Over the past four articles, I’ve spoken a lot about the Ketogenic Diet. What it is, the benefits of it, the different types and even how it works. Today, I’m going to wrap this series up by explaining what exactly happens to your body when you follow the Ketogenic Diet - ketosis.  

I think learning more about nutrition, and in particular, ketosis, is the most important and valuable topic I could have learned about, for me, my family and everyone who puts their trust in me and listens to what I have to say.

Ketosis is the state the body goes into when it breaks down fat for energy. If glucose is not present, the body will break down fat to metabolise ketones, and use these ketones as fuel.

We cannot store fat from fat the same way as we can store fat from carbohydrates. If we eat too much fat, we don’t store it, it simply passes through the body and is excreted as waste.

Ketosis is the state the body goes into when it breaks down fat for energy. If glucose is not present, the body will break down fat to metabolise ketones, and use those ketones as fuel.

It’s the food that you eat which stimulates the release of hormones, specifically insulin, which tells your body to either use or store fat. The three macronutrients we’ve discussed over the recent articles (protein, fat and carbohydrate) are used for different purposes in the body.

Proteins are used to make new enzymes, cells, tissues and organs. Fats are used to make specific tissues such as cell membranes and the brain. In fact, the brain is the fattiest organ in the body, comprising of 60 per cent fat. Carbohydrates are used to provide immediate energy and here’s the kicker; they are converted to fat by the body to store excess energy.

This is important. Much of the food industry wants you to believe that fat makes you fat. Read this article I wrote previously on the sugar versus fat debate. It’s not the fat that you eat that makes you fat, it’s the excess carbohydrate, which gets stored as fat, that makes you fat.

We cannot store fat from fat the same way as we can store fat from carbohydrates. Eating carbohydrates triggers insulin production. Insulin tells the body to convert excess glucose into fat to store it. However, if we eat too much fat, we don’t store it, it simply passes through the body and is excreted as waste.

What Happens to Your Body on Ketosis?

Ketosis is the state the body goes into when it breaks down fat for energy. If glucose is not present, the body will break down fat to metabolise ketones, and use these ketones as fuel.

When you eat carbohydrates, or even extra protein, your body breaks them down into glucose. Glucose is used in the creation of ATP (Adenosine Triphosphate). When ATP is broken down, energy is released.

Your body always needs glucose. But your liver will always ensure you have enough glucose, and glucose comes from more than one source. Therefore, you don’t need carbs in order to get glucose.

One source of glucose comes from protein. About half of excess protein will be turned into glucose. This is not necessarily a good thing though. If you are trying to achieve ketosis, too much protein can knock you out of ketosis.

If you have excess glucose (more glucose than your body can use right then and there), the glucose is converted into glycogen. Glycogen is the storage form of glucose and is stored in your liver and muscles ready for action. However, if you already have enough glycogen in your liver and muscles, the excess glucose will be stored as fat.

When there’s no more glycogen, ketosis occurs. If your body has no access to glycogen, your body breaks down fat that has either just been consumed, or is stored in your body, into glycerol and fatty acids.

Fatty acids are broken down further to produce ketone bodies. Ketone bodies are water-soluble molecules known as acetoacetate, beta-hydroxybutyrate (BHB) and acetone.

When fatty acids are broken down, they produce the ketone body, acetoacetate. Acetoacetate is then converted into two other ketone bodies, beta-hydroxybutyrate (BHB) and acetone. Once your body has adapted to ketosis, your muscles will also convert acetoacetate into BHB.

Most of the acetone which is created is excreted as waste; however, it can be metabolised into glucose if necessary.

In addition, the glycerol which has been created from the initial breakdown of fat is converted into glucose. This process is called gluconeogenesis.

Therefore, as you can see, carbs are not necessary to produce glucose. The body can convert protein into glucose when protein is in excess; plus, the body can metabolise glucose from glycerol and acetone if it needs it.

While glucose is important, it is not the preferred energy source of the brain. BHB is the preferred energy source of the brain. Think of it like clean versus dirty energy. Glucose is like using coal for energy, while BHB is like using solar power. BHB is a much cleaner and effective energy.

In summary, the body still needs glucose. While the brain prefers BHB as an energy source, the body still needs to produce glucose, namely as an important factor in the creation of ATP. As long as your fat and protein intake is sufficient, your liver can perform gluconeogenesis. Then, your body can burn fat as an energy source, releasing fatty acids and glycerol. Remember, glycerol is converted into glucose, while the fatty acids are broken into acetoacetate. Acetoacetate is then converted into BHB and acetone. The acetone can be metabolised into glucose but shouldn’t need to be, so it will most likely be excreted as waste, while the BHB will be used as a super clean and efficient energy source. 

I hope this makes sense. If you have any further questions about what happens to your body on ketosis, please leave your questions in the comments section below.

[Image source: Dashu83 on Freepik]

About Jacob Andreae

About Jacob Andreae

I write and speak about Fitness, Nutrition and Mindset. 

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What Happens to Your Body on Ketosis?A quick start guide to losing weight and staying on track. Learn the strategies I use to eat and move for optimal health. Includes worksheets to enhance your motivation, commitment and discipline, along with a sample eating plan and exercise program.