Since a keto diet involves low fat and high fat, following it for several days puts your body in the state of ketosis, which is a metabolic state where your body uses fat, instead of glucose, as the source of fuel.

Ketosis is also characterized by weight loss and increased blood ketones.

Although the keto diet has been shown to have several potential health benefits, it can also be hard to sustain.

Thus, ketone supplements were suggested to mimic ketosis and increase the levels of your blood ketones without even changing your diet.

However, your body does not interpret it like that. Here we tell you whether or not using exogenous ketone supplements is beneficial for weight loss.

What Happens to Your Body During Ketosis?

Following a diet that involves high carb would allow your body’s cells to use and rely on glucose for fuel.

Glucose is sourced from the carbs in your diet, such as starchy and sugary foods. Restricting these foods on a keto diet forces your body to look for an alternative source for fuel.

Your body then uses fat as a fuel source, which, when broken down in excess, produces ketone bodies, putting your body in a state of ketosis.

It’s natural for most people to experience a mild ketosis state during strenuous exercise or periods of fasting.

During the ketosis state, the body produces three ketone bodies acetoacetate, beta-hydroxybutyrate, and acetone, which replace glucose as fuel and provide energy to your heart, brain, and muscles. Among these ketone bodies, acetone is the least abundant.

It’s thought that these ketone bodies may be the reason behind weight loss associated with a keto diet.

What Are Exogenous Ketone Supplements?

Ketones can either be produced in your body (endogenously) or sourced outside your body (exogenously).

Ketones from supplements are called exogenous ketones, which contain only the beta-hydroxybutyrate ketone. Acetoacetate, which is one of the two primary ketone bodies, is not chemically stable as a supplement.

Ketone supplements have two main forms: ketone salts and ketone esters.

Ketone salts

Most often found in powder form and mixed with liquid, ketone salts are ketone bodies bound to a salt, typically sodium, magnesium, potassium, or calcium.

Ketone esters

Ketone esters are ketones linked to another compound called ester. These ketones are primarily used in research. Packaged in liquid form, they are not readily available for purchase as ketone salts.

Both ketone salts and ketone esters have been found to increase blood ketone levels, which mimic ketosis when following a keto diet.

One study showed that ~ 12 grams of ketone salts increased blood ketone levels of the participants by over 300%.

Most ketone supplements available have 8–12 grams of ketones for every serving.

The increased blood ketone levels caused by supplementation is good for people who want to get into full ketosis without having to follow a low-carb diet.

Therefore, supplementing with ketones is thought to be as beneficial as following a keto diet.

Some even take ketone supplements while following a keto diet, especially when they’re just starting out, to reduce the time it takes to get into full ketosis and the unpleasant side effects that may occur from transitioning into a keto diet.

The unpleasant side effects accompanying the transition to a keto diet, more commonly known as the “keto flu,” include bad breath, headache, diarrhea, constipation, and muscle cramps. Keto flu symptoms can last for a few days, but in severe cases, they can persist for longer periods. It is therefore important that you always stay hydrated.

However, further research is necessary to fully elucidate whether or not ketone supplements can improve these symptoms.

Exogenous Ketones May Suppress Appetite

Ketone supplements were found to reduce appetite, helping you to lose weight by eating less.

A study in 15 people found that those drinking a beverage which contains ketone esters experienced 50% less hunger after an overnight fast as compared with those drinking a sugary beverage.

This effect was attributed to lower ghrelin levels—a hunger hormone—between two and four hours after taking the ketone ester supplement.

However, people who have had a meal beforehand may not experience the effect of ketone supplements on their appetite.

Studies have found that those who didn’t eat a meal before taking a ketone supplement have higher blood ketone levels as compared with those who did.

Since elevated ketone levels are associated with lower ghrelin levels and reduced appetite, ketone supplements may not be beneficial after a meal that contains carbs. They may only be beneficial during a fast.

Although taking a ketone supplement after eating a meal that contains carbs will still increase blood ketone levels, it does not raise the level as high as during a fast. This happens because your body uses fewer ketones as fuel since there is a sufficient amount of glucose from the carbs.

Exogenous Ketones for Weight Loss

However, the potential weight loss benefits of ketone supplements are yet unknown despite their potential appetite-suppressing effects.

Ketone supplements are therefore not yet recommended for weight loss. Some evidence even suggests that they may even be against weight loss.

Ketones Contain Calories

Being used as a fuel source, ketones also contain calories. They have ~ 4 calories per gram, which is the same number of calories as protein or carbohydrates.

One serving of exogenous ketone salts typically contains < 100 calories, but since the effect of ketone supplements lasts only for a few hours, you’ll need several servings every day to get into and remain in the ketosis state.

Side Effects

Although exogenous ketone supplements are generally considered to be safe and effective when it comes to increasing ketone body concentrations, their long-term effects are yet unknown.

Aside from the fact that ketone supplements are said to have a poor aftertaste, there are several reported side effects as well, such as stomach discomfort, diarrhea, and nausea. These side effects are more common with ketone salts than ketone esters.

Moreover, taking ketone salts to get into full ketosis is not recommended due to the high amounts of minerals it contains.

A single serving of ketone salts holds 680-mg sodium, 320-mg magnesium, and 590 mg of calcium.

However, to get into and remain in the ketosis state, you’ll need to take a dose every 2–3 hours. Ketone supplement manufacturers recommend taking up to three servings every day.

It is noteworthy that although ketone supplements can still help you maintain ketosis every after meal, the increase in your blood ketone levels is much less as compared with limiting or totally avoiding carbs in your diet.

Conclusion

Ketone supplements are thought to help your body reach and maintain ketosis even without having to follow a very low-carb diet, such as the keto diet, or any calorie restriction.

A study has found exogenous ketone supplements to suppress appetite for over 4 hours when taken during fasting, but other research, on the other hand, suggests that these supplements may hinder weight loss efforts.

Thus, further research is still necessary to really support the use of ketone supplements as a weight loss aid.