What are Ketones?

Ketones are the molecules that put the “keto” is ketosis and ketogenic dieting.

Ketones, or ketone bodies, are energy molecules that are produced by the liver from burning fat during carbohydrate restriction.  Many of the benefits seen from Keto dieting is a result of the actions produced by ketones.  So, how does this occur?


The production of Ketones is known as ketogenesis.  If you recall from my article on ketosis, carbohydrates tend to be the primary fuel source of our bodies when we are consuming a diet containing carbs.  However, when we restrict our carbohydrate intake, the body must adjust and produce an alternate energy source.  This is when ketogenesis occurs.

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When we stop eating carbs, our blood sugar (glucose) and insulin levels begin to decrease.  This is followed by a response from the body to burn its stored fat.  While this fat can provide energy to fuel many bodily processes, it is unable to be accessed by the brain to provide energy.  This is where ketones come in! Our livers possess the unique capability to break down fat and produce ketones, which we refer to as ketogenesis. 

Interestingly, the liver does not possess the appropriate enzymes to use ketones for energy, so these molecules are instead released into the bloodstream, where they can travel to organs like the brain and be used for energy. Interestingly, some research suggests that much of the body will spare the use of ketones to safe them for use by the brain.

Types of Ketones

The body actually produces 3 different types of ketone bodies.  They are referred to as Acetone, Acetoacetate (AcAc), and Beta-Hydroxybutyrate (BHB).

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Technically, BHB is not a ketone body due to a difference in its chemical structure but is considered one for the purpose of energy metabolism.  BHB is the primary ketone body that we use for energy.

AcAc is the ketone body that is used to produce BHB and is what BHB is broken back down into during ketone metabolism.

While some research suggests that acetone could also be used for energy, it is common for this ketone to be excreted as a waste product in our urine or breath.

In addition to the ketones our body creates, we can also take what is known as Exogenous ketones.  Exogenous ketones are supplemental ketones that when ingested can lead to an acute increase in blood ketones.  While exogenous ketones should not be used in place of a keto diet, they can be a great compliment!

Why Ketones?

You may be wondering why our bodies possess this ability to create an additional energy source.  The answer is simple, survival. 

Remember that the ketogenic diet was found for its ability to closely mimic fasting (food restriction) and ketogenesis is one of the similarities between the two along with the low glucose and insulin.

It has not always been as easy to get food as it is today.  There have been many times in our ancestral history where famine was a fundamental feature of certain seasons.  During times of limited food availability, the body had to adapt by producing energy to survive and keep the brain functioning at a high level.  Ketogenesis provided just that.  Despite the fact that nowadays we go 5 hours without eating, become “hangry” and eat a candy bar, this process still exists and is waiting to be activated.

Benefits of Ketones

Besides providing energy to the body during times of food or carb restriction, ketones can provide numerous other health benefits.

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Seizure Control:

Ketone metabolism by the brain can lead to favorable changes that can limit seizures.

Maintaining Muscle Mass:

Ketones can limit the breakdown of muscle proteins allowing for muscle to be maintained.  This is especially beneficial during calorie restriction when muscle loss is common.  If you are using Keto for cancer, this is a bonus since cachexia or muscle wasting is a hallmark of the condition.

Reducing Inflammation:

Ketones can reduce inflammation by activating anti-inflammatory molecules reducing the production of free radicals, which contribute to inflammation.

Improved Brain Health:

Ketones have been shown to improve the brain function of those suffering from neurodegenerative diseases like Alzheimer’s.

Lower Blood Sugar:

When ketosis is achieved nutritionally (via fasting or keto dieting) we also see a subsequent drop in blood glucose levels which can have many various health implications.

Reduced Hunger:

Ketones can signal to the brain that energy is present and limit the production of hunger hormones. There are several other mechanisms behind how ketone can promote fullness but for simplicity sake know that this is a commonly experienced benefit.

Mitochondria Health:

Mitochondria are the part of our cells that are responsible for metabolism and energy production.  It is actually this part of the cell that is often damaged in many diseases such as cancer.  Ketones can improve mitochondria health and function.

Enhanced Athletic Performance:

Ketones have been shown to improve exercise endurance, limit muscle soreness, and improve recovery.


Ketones are very interesting energy molecules, particularly because some of us haven’t produced many of them over the course of our lives.  While carbs are considered to be our primary energy source, overtime they can lead to insulin resistance and inflammation.  Fat and ketones can provide the energy we need to survive, thrive, and improve our health.

If you are looking to learn more about keto, check out my article What is Keto? If you are ready to start keto, signup below and I’ll send you everything you need to know to get started right!

Christopher Irvin