What Are Ketones?

minute read | Last update: Nov 30th2022

This article is backed by studies and reviewed by a certified dietician.

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You’ve recently started the keto diet, so you’re trying to produce ketone bodies, more commonly referred to as ketones. Yet you’ve heard mixed things on the safety of ketones, which has given you pause. What exactly are ketones?

Ketones are molecules that come from the liver. The ketones exit the liver and become acetyl-Coenzyme A. Your brain can make acetyl-CoA into long-chain fatty acids such as acetone, beta-hydroxybutyrate, and acetoacetic acid that you use for energy.

If ketones still don’t quite make sense to you yet, don’t panic. In this article, we’ll explain ketones extensively as well as whether ketones are dangerous for your health. Before you start the keto diet, you’ll want to read this!

Understanding Ketones

Let’s start by delving further into ketones, including what they are, what they do, and when your body produces them.

Ketone bodies or ketones are made through the liver. These molecules are water-soluble, which means they’re dissolvable in water. Your body can produce three kinds of ketone bodies, as we touched on in the intro. These are acetone, beta-hydroxybutyrate, and acetoacetic acid.

Let’s talk more about each type of ketone now.

The Three Types of Ketones

1. Acetone

Also known as propanone, acetone is a type of compound that’s flammable, pungent, and colorless. Your body normally makes acetone through processes related to metabolism. The acetone remains in your urine or blood until you expel it.

If you’ve been diagnosed with diabetic ketoacidosis, then your acetone levels will be more elevated than normal. Those on the keto diet will also have higher traces of acetone.

2. Beta-Hydroxybutyrate

The second type of ketone body is beta-hydroxybutyrate or 3-hydroxybutyric acid. This compound undergoes liver synthesis when fatty acids metabolize. Then they become acetoacetate, the third ketone type.

Since beta-hydroxybutyrate is produced in your blood plasma, when your blood glucose levels begin to drop, the amount of the compound goes up so your body can use it as an energy source.

3. Acetoacetic Acid

Acetoacetic acid or acetoacetate is an unstable beta-keto acid compound. That makes it a weaker form of acid.

How Are Ketones Formed?

Okay, so now that you know more about the types of ketones, where do they come from? We went over the process briefly in the intro, so let’s expand on it more now.

Ketone bodies form in your liver. The liver takes ketogenic amino acids and fatty acids and makes them into ketone bodies through a process called ketogenesis. The ketones can spread to tissues beyond the liver and travel.

Your body will make the ketones into acetyl-Coenzyme-A or acetyl-CoA, a type of carbohydrate and protein molecule. The acetyl-CoA molecules go through Kreb’s cycle, which is also known as a citric acid cycle.

During the citric acid cycle, chemical changes oxidate the acetyl-CoA to release the energy from the proteins, fats, and carbohydrates in these molecules. The brain’s ketone bodies can kickstart an acetyl-CoA conversion process that results in long-chain fatty acid production. That’s how you get the ketone bodies acetone, beta-hydroxybutyrate, and acetoacetate.

When Does the Body Make Ketones?

Ketone production is not a continual process within the body. It happens only when your body has no glycogen left in the liver.

When you eat, the food you consume enters the body as glucose, a simple sugar that’s more prominent in sugary and carb-heavy foods. The liver converts glucose into usable energy known as glycogen during glycogenesis. It’s sort of like how when you visit a new country, you convert your currency to what that country uses.

Your body uses glycogen for energy. When the body has more glycogen than it needs, the excess gets sent to the liver. It’s then stored for an emergency.

When you enter a fasted state or go on a carbohydrate-restricted diet such as keto, you burn through your supply of glycogen quickly. If the body has no current supply of glycogen left, then it goes to the stores in the liver.

What happens when even that glycogen is gone? That’s when you produce ketones as an alternate energy source.

Although exercise does cause your body to use glycogen, if you eat anything afterward, especially carbohydrates, then that glycogen fluctuation is short-term. You’d have to exercise hard for a long time or combine exercise with fasting or keto to deplete glycogen stores.

Are Ketones Bad or Are They Safe?

Although the average non-dieting person doesn’t produce ketone bodies all that often, that doesn’t mean you should automatically jump to the conclusion that ketones are dangerous.

A ketone is merely an alternate form of energy that your body uses when it doesn’t have its original source of energy, which is glycogen. The production of the three types of ketone bodies isn’t abnormal, so even if their levels are higher in a keto dieter compared to someone who isn’t dieting, your health should not be at risk.

There is one exception though, and that’s if you’re a diabetic. Your body already has a hard time controlling your levels of glucagon and insulin. If you have high ketone levels, this is usually a sign that you’re not effectively treating your diabetes, especially if you have type 1 diabetes mellitus.

With type 1 diabetes, you’re deficient in insulin since your number of beta cells goes down, with beta cells being what produce insulin.

So what would happen if you’re a type 1 diabetic and your ketone levels skyrocketed? The ketones accumulate in your blood. You might feel ill but ignoring the problem from there will only worsen your health. You have a much higher likelihood of developing ketoacidosis. All the ketones in your system can be toxic as well.

Let’s rewind for a moment, as we’ve already mentioned ketoacidosis once. What exactly is it?

Ketoacidosis is a condition that can occur among diabetics. It’s considered a medical complication that develops when insulin production is very low.

Your body will use fat as energy, which causes an acidic buildup of ketones. The symptoms of ketoacidosis are confusion, feeling unable to breathe, fatigue or weakness, stomach pain, vomiting, urinating more often, and feeling very thirsty.

Your breath might smell fruity even though you didn’t ingest anything sweet.

Untreated ketoacidosis can be fatal, so diabetics must manage their blood glucose levels every day.

How Many Ketones to be in Ketosis?

If you’re not diabetic, then proceeding with the keto diet should be perfectly safe. You can always schedule an appointment with your primary care physician to discuss your dietary changes before you begin. After a checkup, if you’re in good health, your doctor should give you the green light.

When you start the keto diet, how many ketones must you make to enter a state of ketosis? Well, the process is slow-going at first. Remember, your liver has stores of glycogen it has to burn through.

After that happens, you’ll need a ketone meter to determine the number of ketones in your blood. To use the meter, put a needle in the lancet pen using clean, freshly washed hands. Then take one test strip, unwrap it from its packaging, and put it in the testing meter.

Position the lancet pen on your fingertip on either side but not the center. Press the button and squeeze to get a blood sample. Transfer the blood to the test strip and the meter will begin reading your blood glucose.

Your reading should be anywhere from 0.5 to 3.9 milligrams per decilitres or mg/dL. If your blood ketones are a lot higher than that, like upwards of 10 times higher, then you might have ketoacidosis. You should call your doctor immediately.


Ketones are a type of energy source your body uses when it has no leftover glycogen from food, especially carbs. The keto diet is one way to encourage the production of keto bodies, as is fasting and other restricted diets.

For most people, producing more ketones and burning them for energy is perfectly healthy. Yet if you have ketoacidosis, higher than usual levels of ketones are typically indicative of poor diabetes management. You must start prioritizing your health, as severe ketoacidosis can be fatal.

About the author

The Authentic Keto Team is here to bring you health tips that help you with losing weight fast. We focus on a clean keto diet for beginners because we believe that is the easiest and most simple way to healthy eating. Our keto weight loss tips will not only bring you into ketosis fast but will also help you to improve your mental health, sleep problems, and wellness.

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