"What Are Ketones?" A Complete Guide by SuperFat

Written by Lynn Hetzler
on June 15, 2019

Ketones are the key to a ketogenic diet, which is one of the most popular diets in the nation. It focuses on a process that causes the body to burn fat, instead of sugar, for energy.

What are ketones?

Ketones are a natural substance made when the human body burns fat for energy. A person’s body might also produce ketones when he or she loses weight or when there is not enough insulin to turn sugar into energy. Additional ketone specifics here.

The liver produces ketones, also known as ketone bodies. There are three main types of ketone bodies:

  • Acetoacetate, or ACAC.
  • Beta-hydroxybutyrate, or BHB.
  • Acetone.

The human body normally uses sugar, or glucose, as energy. It gets this sugar through carbohydrates in certain foods, such as grains, starchy vegetables, fruit and juice. The digestive tract turns carbohydrates into glucose, which travels to body cells through the bloodstream. A hormone, insulin, unlocks the cells so that they can absorb glucose from the bloodstream.

When there is not enough insulin to use sugar for energy, the body starts to use fat as fuel instead. The liver turns fat into ketones, which enter the bloodstream to reach the cells of the body. Muscles and other body tissues can use these ketones as energy. Medical professionals refer to this natural process of burning fat instead of sugar as ketosis.

Ketosis is a nutritional state, characterized by high ketone levels and weight loss. Because it burns fat and causes weight loss, ketosis is a popular weight loss strategy, known as a ketogenic or ketodiet. In general, ketogenic diets are very low in carbohydrates and high in fat. There are several versions of the ketogenic diet, according to Healthline, including:

  • Standard ketogenic diet. High-fat meals typically contain 75% fat, 20% protein and only 5% carbohydrates.
  • Cyclical ketogenic diet. Eat a ketogenic diet for five days; then consume a high-carb diet for two days.
  • Targeted ketogenic diet. Consumers can add carbohydrates around their workouts or competitions.
  • High-protein ketogenic diet. Similar to the standard ketogenic diet, this diet includes greater amounts of protein, with a typical ratio of 60% fat, 35% protein and 5% carbohydrates.

Eating this diet for several days puts the body into ketosis, which means the body now burns fat instead of sugar for energy. In a meta-analysis of 13 studies, five studies showed significant weight loss benefits from a ketogenic diet. Harvard School of Public Health notes that the ketogenic diet produces a satisfying effect with decreased food cravings, decreased appetite, increased calorie burning due to the metabolic effects of converting fat into energy, and the promotion of fat loss without losing lean muscle mass. Ketogenic diets also provide short-term improvements in total cholesterol, blood sugar and blood pressure.


While a ketogenic diet provides benefits, it can be difficult to maintain long enough to realize significant weight loss. Restricting carbohydrates for days or weeks at a time can cause hunger, fatigue, irritability, low mood, constipation, headaches and brain fog. While these unpleasant effects subside, staying satisfied with the limited variety of food offered in a ketogenic diet can be challenging. Many people turn to supplements that help them remain in a state of ketosis, even as they consume carbohydrates.

Diabetic ketones and diabetic ketoacidosis ("DKA")

The presence of ketones is not a health hazard, except in people with diabetes. In those people, high ketone levels can be dangerous. A high ketone level in someone with diabetes is diabetic ketoacidosis, which is a dangerous condition.

Ketosis and ketoacidosis are two different things. Ketosis is a natural state that can happen in healthy people, whereas ketoacidosis is a health emergency that happens to people with diabetes.

About 30 million people in the United States have diabetes, according to a 2017 report by the Centers for Disease Control and Prevention. A high blood sugar level, also known as hyperglycemia, is the main characteristic of diabetes. High glucose levels typically happen when there isn’t enough insulin or when the cells of the body resist the effects of insulin, a condition known as insulin resistance.

There are two main types of diabetes. Type 1 diabetes occurs when the pancreas does not make enough insulin. Type 2 diabetes occurs when the pancreas does not make enough insulin or when the cells resist insulin's effects. Inadequate insulin in people with diabetes can cause diabetic ketoacidosis, which is a serious and potentially life-threatening condition that needs immediate medical attention.

Diabetic ketoacidosis usually develops slowly, but when vomiting is present, it can develop over just a few hours.

Signs and symptoms of diabetic ketoacidosis

Early signs and symptoms of diabetic ketoacidosis include:

  • Thirst and extremely dry mouth.
  • High blood glucose levels.
  • Frequent urination.
  • High levels of ketones in the urine.

Left untreated, other symptoms of diabetic ketoacidosis develop. These signs and symptoms include:

  • Feeling tired constantly.
  • Dry or flushed skin.
  • Nausea and vomiting, although many illnesses can cause vomiting.
  • Abdominal pain.
  • Difficulty breathing.
  • Fruity odor on breath.
  • Confusion and difficulty paying attention.

Diabetic ketoacidosis can happen in anyone with diabetes, but it is rare in people with Type 2 diabetes, according to the American Diabetes Association.

Ketone testing

What are ketones and what is ketone testing

The body tries to get rid of ketones through urine and through the respiratory tract. This means ketones may be present in urine, a condition known as ketonuria, during diabetic ketoacidosis. Ketones also give urine and breath a fruity odor during diabetic ketoacidosis.

Urine, breath and blood tests can measure ketones, but most tests look for ketones in urine. Small or trace amounts of ketone bodies in urine may mean that ketoacidosis is starting, while moderate or large amounts of ketones may be dangerous.

Urine testing is easy to perform at home or in a medical laboratory setting. A urine testing kit includes a set of strips that, once dipped in urine, will change color. The consumer simply compares the color of the strip against a chart that comes with the test kit to determine ketone levels. Some urine test results report the numbers that you compare against a “normal range” of numbers. Urine test results may also report in general terms, such as:

  • No ketones.
  • Trace amounts of ketones.
  • Moderate levels of ketones.
  • High levels of ketones.

Trace amounts of ketones may mean that ketoacidosis is beginning. Low levels of ketones may also indicate a missed insulin shot, which may be remedied with a dose of insulin. Someone with moderate ketones should call the doctor, who might suggest going to the nearest emergency department. Anyone who has moderate to high levels of ketones in his or her urine should seek medical help immediately, as this may be a sign of ketoacidosis.

Drinking water can help flush out excess ketones. Testing blood sugar every three to four hours is suggested to determine if blood glucose levels are rising. Anyone with high blood sugar and high ketones should avoid exercise, according to the Joslin Diabetes Center, as physical activity during ketoacidosis burns fat and produces more ketones.

Causes of ketoacidosis

Illnesses and problems with insulin therapy may trigger diabetic ketoacidosis, according to the Mayo Clinic. Other triggers may include physical or emotional trauma, a heart attack, alcohol or drug abuse, and the use of certain medications, such as corticosteroids that treat inflammation and some diuretics, also known as water pills. Not eating enough can also trigger diabetic ketoacidosis, as can an insulin reaction.

The risk of diabetic ketoacidosis is highest in people with Type 1 diabetes and who frequently miss insulin doses, although ketoacidosis can occur in those with Type 2 diabetes.

Prevention and treatment of diabetic ketoacidosis

Ketoacidosis prevention includes a strong commitment to managing diabetes through diet, exercise and medication, monitoring glucose levels, adjusting insulin doses as needed, checking ketone levels regularly, and being prepared to act quickly. The American Diabetes Association suggests people with diabetes check their glucose levels every four hours when they have a cold, flu or other illness, or when blood glucose is over 240 mg/dl.

Treatment for diabetic ketoacidosis usually involves fluid replacement through intravenous fluids or by drinking fluids, electrolyte replacement, and insulin therapy. Fluid replacement has two main objectives: to replace fluids lost through excessive urination and to help dilute the excess glucose in the blood. Electrolyte replacement, delivered through an IV, replaces the sodium, potassium, calcium and other electrolyte minerals involved in keeping the heart, muscles and nerve cells functioning properly. Insulin reverses the ketoacidosis process.

Ketone supplements

Scientists refer to ketones made inside the body as endogenous ketones. Ketones can come from outside sources too, such as supplements. These are known as exogenous ketones. The goal of these exogenous ketones is to increase blood ketones, mimicking what happens on a ketogenic diet.

Supplements contain only the beta-hydroxybutyrate ketone body, as the other primary ketone body is not chemically stable in supplement form. There are several different types of exogenous ketone supplements, and each works in a different way.

Ketone esters

Ketone esters are pure ketones that the body uses immediately. On the downside, ketone esters tend to have an unpleasant rubbing alcohol-like taste.

Ketone salts

Ketone salts bind the ketones to calcium, magnesium, sodium or potassium, which improves the body’s ability to absorb the ketones. Because they mix well with drinks, most exogenous ketone supplements use ketone salts.

MCT oils

Medium-chain triglyceride oils are also widely distributed, as they provide quick ketosis and are typically tasteless. They can cause gastric distress, especially when someone first starts using them.

Raspberry ketones

Raspberry ketones give raspberries their distinct aroma. Many fruits, such as blackberries and cranberries, also contain raspberry ketones.

Raspberry ketones in supplements, however, are not derived from raspberries. Extracting raspberry ketones from fruit to use in supplements would be cost-prohibitive, as it would take 90 pounds of raspberries to make a single dose. The raspberry ketones in supplements are synthetic; furthermore, raspberry ketones do not have the same ketogenic effects on the body as low-carbohydrate diets.

Raspberry ketones have a molecular structure similar to capsaicin, which is the active ingredient in chili pepper, and to the stimulant synephrine. Research suggests raspberry ketones cause fat within the cells to break down more effectively to help the body burn fat faster. Raspberry ketones may also increase levels of adiponectin, which is a hormone that helps to regulate metabolism.

Top 10 exogenous ketone supplements

  1. HVMN Ketone Ester contains 25 grams of ketone ester and zero caffeine, sugar, salt or fat. It is compliant with a ketogenic diet, fasting and professional sports.
  2. Perfect Keto Exogenous Ketone Salt contains BHB, which makes it easy to enter a state of ketosis and remain there.
  3. Zhou Nutrition KETO DRIVE BHB Salts contain BHB along with other nutrients, such as vitamin A, calcium, sodium and magnesium.
  4. Kiss My Keto C8 MCT Oil contains MCT oil. Made from coconut oil, MCT oil provides healthy fats that the body uses to produce ketones for long-lasting fuel.
  5. Level Up Clean C8 MCT Oil claims to be pure caprylic acid oil, which provides superior energy by removing chemical structures that might inhibit the body’s usage of MCT. This means the body does not store the Clean MCT Oil as fat, but instead converts it to ketones instantly.
  6. Perfect Keto MCT Oil Powder is the only MCT oil to use acacia fiber, which is a prebiotic that promotes gut and cellular health.
  7. Zhou Nutrition MCT Powder with Prebiotic Fiber provides 4 grams of healthy fats, 5 grams of acacia prebiotic fiber, and zero net carbohydrates.
  8. BioKeto contains premium grade BHB exogenous ketones that boost ketone production and optimize ketosis.
  9. KetoFIRE contains a lipase blend that promotes the healthy digestion of fat by breaking down fats into small components that are easy to digest.
  10. Keto Lift contains vitamins and caffeine in addition to exogenous ketones, providing a burst of mental alertness.
  11. Nitro Coffee Nut Butter + MCT contains MCT, plus almond and macadamia nut butter, along with coffee, to support metabolism.

When taken as directed by healthy individuals hoping to lose weight by burning fat, ketone supplements are a safe and effective addition to a ketogenic diet. 


Written by: Lynn Hetzler

Lynn has been a leading writer in the medical field for 20 years. She specializes in creating informative and engaging medical content for readers of all levels, from patients to researchers and everyone in between.


Written by Lynn Hetzler

Published: June 15, 2019