Keto Breath Is a Difficulty for Low-Carb Dieters

Bad breath is one of the possible side effects of low-carb diets such as the Atkins diet, the South Beach Diet, and the Ducan diet. Known as ketosis breath, or simply keto breath, this condition is often accompanied by a foul odor in the mouth. While these symptoms can be disastrous, there are several things you can do to overcome them without compromising your dietary goals.


Bad breath has many causes. However, a low-carb diet has two main causes: ketosis (the metabolic state achieved by a low-carb diet) and protein metabolism.


One of the body’s main energy sources is glucose. Glucose is created when the digestive tract breaks down carbohydrates from complex sugars into simple glucose molecules. By reducing the number of carbohydrates ingested, the body needs to find an alternative fuel source (fat) for energy. This is a metabolic state called ketosis.

When the body breaks down fatty acids, it produces byproducts called ketones. Common ketone bodies come in three forms: acetoacetate, beta-hydroxybutyrate, and acetone. These ketone bodies are regularly removed from the body by urination and exhalation.

When you’re on a low-carb diet, your body isn’t eating more carbs, so you’re more dependent on fatty acids for energy. As your body runs out of more fat, more ketones are released as a byproduct of metabolic processes at work. Excessive accumulation of ketones in the body can cause bad breath.

However, the exhaled ketone has a very unique scent, most of which is different from what you feel with your daily bad breath (bad breath).

Protein Metabolism

Dietary changes can also cause changes in breathing. In a low-carb diet, the sudden switch from carbohydrates to protein changes the way your body metabolizes food.

The decomposition of proteins in the body produces ammonia. A sudden spike in dietary protein only amplifies this effect, increasing ammonia levels in both gas and urine.

A large amount of water is required to expel ammonia, so ammonia accumulates quickly in the body, which can make bad breath worse if you are not well hydrated.


Keto breathing varies from person to person but is generally different from bad breath. The bad breath that most of us experience from time to time is caused by bacteria in the mouth. When these bacteria begin to break down the food we eat, they produce volatile sulfur compounds (VSC). Usually, these compounds have a sulfury odor (similar to rotten eggs).

Keto breath has different odor characteristics depending on which by-products of protein and fat metabolism are produced. For example:

Acetoacetate and beta-hydroxybutyrate create a sweet, fruity scent in your breath. Some people describe the smell as being similar to a damaged or rotten apple.
Breath acetone creates more of a resinous (like manicure) odor.
Excessive protein metabolism can lead to the aroma of ammonia in both respiration and urine.

In most cases, keto breathing disappears spontaneously but can take weeks to a month. If you are working on a low carb diet, there are several ways to relieve the symptoms of keto breathing while your metabolism is regulated. Drink more water.

Aim for more than 8 glasses of 8 ounces a day. This not only helps flush out excess ketones and VSCs from your body but also aids digestion and prevents constipation.

Change The Balance Of Protein Intake.

This is a process of trial and error, but changing the protein source (eg, chicken to meat, or meat to fish) may change the ketone bodies produced (because primarily fatty acid types begin to break down).

Increase Your Fat Intake.

Research suggests that you can increase fat while reducing protein consumption and minimize emissions of both acetone and ammonia.

Do Not Undercut Carbohydrates?

Don’t be too enthusiastic to cut more carbs than you need. For example, the South Beach Diet has fewer carbs than the Atkins Diet. However, neither is aiming for a zero-carb policy. If you think you have gone too far in cutting carbohydrates, try increasing your healthy carbohydrate intake within the limits.

Mask Your Breathing

Try natural breath fresheners (mint, parsley, cloves, cinnamon, fennel seeds, etc.) or breath capsules made from parsley oil or chlorophyll.

Made from xylitol, sugar-free mint and gums help mask bad breath while exerting mild antibacterial properties that control VSC.

Practice Good Oral Hygiene.

Brush your teeth, apply floss, and rinse with an antibacterial mouthwash. Regular rubbing of the tongue is also effective.