Keto breath is when a person’s breath smells fruity or sweet. It is a side effect of following a ketogenic diet and being in ketosis. An individual can try to reduce this by drinking more water, slightly increasing the number of carbohydrates they eat, or using mints.

A ketogenic diet, or keto diet, involves a person eating very few carbohydrates. Instead, they get their calories from consuming fats and protein. People may describe the resulting breath smell as being fruity or sweet.

Some people claim that keto breath will disappear once the body adapts to being in ketosis. Researchers think it takes at least 21 days to reach this state.

By this point, a person’s body is more effective at burning the ketones it produces. This means there are fewer ketones to breathe out, which implies keto breath should improve.

Until then, people can try to reduce or mask their keto breath by:

Woman drinking a glass of water to try and get rid of keto breathShare on Pinterest
A person should drink more water to reduce keto breath.

Many people suggest that drinking more water may help reduce a person’s keto breath.

This is because the body expels more ketones in urine rather than as a breath.

By drinking water, people will produce more urine, which will help expel many of the ketones from the body.

Drinking water may also help flush out bacteria in a person’s mouth that could be causing bad breath.

When a person drastically reduces their carbohydrate intake, their breaks down fats for energy, which produces ketones. However, a person does not have to avoid all carbohydrates to achieve ketosis.

The number of carbohydrates a person can eat without dropping out of ketosis will be different for each person but could be 20 (grams) g to 50 g if a person is consuming 2,000 calories a day.

Eating more carbohydrates should mean a person produces fewer ketones. As a result, they should breathe fewer ketones out and have less keto breath.

People may use mints to mask keto breath. Sucking mints or chewing mint gum may be enough to hide the smell of keto breath.

Chewing gum also increases the amount of saliva a person produces, which can help stop the bacteria that cause bad breath from growing in a person’s mouth.

According to a study in the International Journal of Oral Science, lack of saliva may be a cause of bad breath in the morning. During the night, a person’s mouth produces less saliva, which allows more bacteria to grow.

Not only does the minty odor of toothpaste help mask the smell of keto breath, but brushing the teeth will help dislodge pieces of food in the mouth and teeth that can smell as they break down in a person’s mouth.


There is not a clear way of preventing keto breath. Anecdotally, it is a side effect that almost everyone who puts their body into ketosis will experience.

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A person who has keto flu may experience nausea, dizziness, and headaches.

Keto breath is a clear sign a person is in ketosis. Another key sign is keto flu. According to some reports, keto flu normally goes away after a few weeks, once a person’s body adapts to ketosis.

According to the National Center for Biotechnology Information (NCBI), a person who has keto flu is likely to experience some of the following symptoms:

Another possible sign of ketosis is a change in a person’s urine. Because of the increase in ketones a person’s produces, their urine is likely to be darker and have a stronger smell.

Some people report that they have less appetite when in ketosis — although scientists are not sure why this might happen.

Fat and protein intake puts a person’s body into a state of ketosis.

Typically, carbohydrates provide a person’s body with glucose, which the body burns to generate energy.

When a person restricts their carbohydrate intake, their body produces glucose. When this is not enough, it produces ketones that it burns for energy.

When a person has little glucose in their blood, the body stops storing fat and starts using it for energy. It breaks down the fatty acids, turning them into acetones.

It is this increased level of acetone in a person’s body that produces keto breath.

The keto diet is very effective at helping a person reduce weight quickly in the short-term.

According to an article in the European Journal of Clinical Nutrition, some evidence shows that the keto diet may also be beneficial for a person in other ways.

Additional benefits of the keto diet include reducing the risks of diabetes, reducing cardiovascular issues, and treating epilepsy.

Less well-established evidence of the additional benefits of the keto diet includes improving acne, polycystic ovary syndrome, and some neurological issues.

Adverse effects

People who switch to the keto diet may experience a number of short-term side effects, known collectively by some as the “keto flu.” These include:

Long-term side effects can include fatty liver disease, kidney stones, and abnormally low levels of protein in the blood.

A person can mask keto breath by using mint, and they may also be able to reduce it by increasing the number of carbohydrates they consume and drinking more water.

However, according to anecdotal evidence, keto breath should go away as a person’s body burns more ketones for energy because there are fewer ketones for a person to breath out.