What are Ketones?
Ketones put the keto in ketogenic dieting. Ketones, or ketone bodies, are energy molecules that are produced by the liver as a byproduct of fat burning. Ketones can be used as a source of energy by nearly every cell in the body, but are primarily used by our brain.
While ketones have previously been considered dangerous and even life-threatening due to their link to diabetic ketoacidosis, ketones produced during carbohydrate restriction, like on a keto diet, can provide a wide array of benefits. Let’s take a deeper look at ketone production.
How are Ketones Created?
When we are following a carb-heavy diet, like the standard American diet, our body's primary fuel source is carbohydrates. However, when we restrict carbohydrate intake, our bodies have to adjust to using a different fuel source. It does so by burning fat and producing ketones through a process known as ketogenesis.
When we stop eating carbs, our blood sugar (blood glucose) and insulin levels lower, and our pancreas starts pumping out the hormone glucagon. Glucagon tells our body that it does not have enough glucose and it is time to release stored fatty acids so that they can be used as energy. While the body burns a lot of the fat released from storage, some of the fat ends up in the liver, which is where ketogenesis occurs.
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. This is an important process since our brain cannot use fat for fuel, thus relying on ketones for energy when carbohydrates are not available (or avoided).
When we have elevated levels of ketones, our bodies are said to be in a state of ketosis.
Types of Ketones
The body produces 3 different types of ketone bodies. They are referred to as Acetone, Acetoacetate (AcAc), and Beta-Hydroxybutyrate (BHB).
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 to help achieve a deeper state of ketosis for particular goals.
Why Do We Make Ketones?
You may be wondering why our bodies possess this ability to create an additional energy source. The answer is simple, survival.
The ketogenic diet was founded for its ability to mimic fasting and ketogenesis is one of the primary 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. This is where ketones and ketogenesis come in.
Despite the fact that nowadays we can hardly make it a few hours without eating and becoming hangry, this process still exists inside each of us and is waiting to be activated.
Benefits of Ketones
Besides providing energy to the brain and body during times of food or carb restriction, ketones can provide numerous other health benefits. Let’s touch on a few of the big ones.
The first use of the keto diet was for its ability to mimic fasting, which back in the early 1900s was a common treatment for epilepsy. Research has found that when the brain is metabolizing ketones, favorable changes occur in the brain that can prevent or at least limit seizures.
Maintaining Muscle Mass:
One of the survival benefits of ketones is their ability to limit the breakdown of muscle proteins allowing for muscle to be maintained when calories are scarce. This is one of the major reasons why keto is superior for weight loss since most weight-loss diets result in the loss of precious muscle mass.
Inflammation is one of the primary drivers of our most common chronic health conditions. When our bodies are metabolizing a lot of carbs for energy, reactive oxygen species are produced, which in excess can lead to inflammation.
Ketones can combat inflammation by producing less inflammation when metabolized and by activating natural anti-inflammatory pathways.
Improved Brain Health:
Remember, that ketones are primarily used by the brain. Ketones are a superior energy source for the brain since they produce more energy and less inflammation. This is one of the many reasons why research is starting to show that ketones can improve brain function and improve symptoms of neurodegenerative diseases like Alzheimer’s.
Lower Blood Sugar:
High blood sugar is a fundamental feature of most metabolic health conditions, especially diabetes. When ketosis is achieved nutritionally (via fasting or keto dieting) we also see a subsequent drop in blood sugar levels. This is why keto is now being used more commonly for diabetes management and controlling blood glucose levels.
Remember that ancestrally speaking, ketones were produced during times of limited food availability. Besides providing energy, ketones can also signal to the brain that energy is present and limit the production of hunger hormones. This is why many keto dieters will report much less hunger and cravings while on the diet.
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 metabolic diseases such as cancer, diabetes, and metabolic syndrome. Ketones can reduce damage to mitochondria and actually promote mitochondrial repair to improve the health and function of this important part of our cellular machinery.
Enhanced Athletic Performance:
One of the first performance-based uses of the ketogenic diet was for endurance performance. Ketones have been shown to improve exercise endurance, limit muscle soreness, and improve recovery.
What is the Best Way to Measure Ketones?
To determine if we are in a state of ketosis, ketones can be measured in the blood, breath, and urine. Up until recently, blood tests, which are done similarly to how blood sugar is measured, have been considered the gold standard of measuring ketones. However, research has found that some of the new breath ketone test devices hitting the market are also great predictors of ketosis without the invasive component of pricking your finger and drawing a blood sample. Keto urine test strips are also a less invasive way to measure ketones but are less accurate compared to blood and breath.
Ketosis can also be "measured" by looking for benefits of ketones such as increased energy, mental clarity, lower body fat percentage, and improved mood. You can also tell when you are in a state of ketosis by the dry mouth and a fruity smell in your urine and breath, which is a result of the ketone molecule acetone being excreted from the body.
How often should you test ketones?
When first starting a ketogenic diet, ketone testing more frequently can be a great way to determine if you are following the diet properly. For this reason, many new keto dieters will test several times per day at the start of the diet.
As your body gets accustomed to producing and utilizing ketones for energy, testing does not need to be done as frequently. The best times to test ketones are fasted in the morning and following a meal to determine the impact of certain foods on your state of ketosis.
What is the optimal ketone level?
While research often suggests that the optimal level of ketosis is somewhere between 0.5-3.0 mmol (measured on a blood meter), the truth is that the optimal ketone levels differs from person to person and goal to goal. Through measuring your ketones and relating them to how you feel, you can determine your own optimal ketone level which will be much more accurate than whatever research is telling you to shoot for.
Are Ketones Dangerous?
Ketones have gotten a pretty bad reputation due to their link to diabetic ketoacidosis (DKA). It’s important to note that DKA is much different from nutritional ketosis. DKA, experienced during type 1 diabetes and less commonly type 2 diabetes, is the uncontrolled rise of ketones due to not enough insulin which allows them to reach a level of toxicity in the blood. While these high levels of ketones are a medical emergency, during nutritional ketosis ketone levels never reach this level and instead only reach a point where they are able to provide energy and the benefits listed a few sections ago. Long story short, ketones produced on a ketogenic diet are safe and beneficial.
Ketones are energy molecules produced as a result of a low-carb diet or fasting that allow these diet strategies to provide much of their benefits. Due to the nature of what has become the conventional human diet, many of us have not produced ketones since we were babies. Restricting carbs and fasting is a great way to alter your metabolism to start producing these beneficial ketone bodies again which can lead to both short-term and long-term benefits