Ketosis Breath: Causes & Solutions for Bad Breath

Ultra-low carb diets have grown in popularity over recent years. These so-called “keto diets” aim to facilitate rapid weight loss through the consumption of minimal carbohydrates.

Keto diets have become understandably popular on account of their rapid results, together with the practical benefits of consuming healthy volumes of the right foods, making hunger less of a problem than on more typical calorie-controlled diets.

However keto diets are not without their issues, and one of the most common complaints comes in the form of “ketosis breath”. Quite simply, many individuals making use of very low carb diets suffer from pungent and unpleasant breath.

The question is; what can be done to counteract such a problem?

The Cause of Ketosis Breath

In order to learn how to get rid of keto breath, we first need to understand why breath can smell under such a regime.

As it turns out there are two potential reasons(1), both of which can operate independently, or in conjunction.

Ketone Release

The most typical source of energy used by the body is glucose. This is typically derived from carbohydrates, where the digestive system breaks down complex sugars into simple glucose molecules.

On very low carb diets, however, the body is unable to utilise such a fuel. Instead, the liver utilises the fat present in the body as an energy source, producing “ketones” in the process(2). This is known as “ketosis” – and is the process from where keto diets get their unusual name.

These ketone bodies come in three common forms; acetoacetate, beta-hydroxybutyrate and acetone. In large quantities they are removed from the body in the urine or through exhalation.

Ketones can have quite a characteristic smell; they often make the dieter’s breath smell quite sweet and fruity, quite distinct from typical halitosis.

Excessive volumes of acetone, however, can smell rather different. Acetone on the breath is most commonly likened to the smell of nail varnish remover.

Protein Excess

A second possible cause of ketosis breath isn’t directly linked to the breakdown of fat as a fuel source.

Instead, it is a side issue caused by typical changes to the diet. As those on keto diets try to minimise the consumption of carbohydrates, so the diet is often filled with other constituents; most typically fat and protein.

A diet that is high in protein can have two impacts on breath. Firstly, the breakdown of protein in the body produces ammonia; this can lead to urine or breath smelling particularly strongly. If your breath has started to smell like a cat litter tray while on a ketosis diet then this may well be your culprit!

Standard bad breath is most commonly caused by bacteria in the mouth. This bacteria breaks down its food, producing volatile sulphur compounds (VSCs.)

It is interesting to note that studies suggest that the most common source of VSC production is the breakdown specifically of protein, as opposed to other food sources. Higher protein diets, especially in the absence of suitable oral hygiene, can also therefore impact one’s breath.

How to Stop Ketosis Breath

As you can see, keto diets can impact one’s breath in a number of ways; through providing extra food for bacteria, to increasing ammonia production, and also the release of ketones and acetone.

Eliminating ketosis breath effectively will largely depend on the specific cause of bad breath.

The following steps can be beneficial to getting rid of bad breath caused by keto diets:

Come Out of Ketosis

Coming out of ketosis is of course the most effective way to get rid of ketosis breath. By raising your carbohydrate intake gently your body should stop producing ketones, meaning fresher breath.

That said, if you’re on a keto diet already, it’s unlikely that this option will sound too tempting. After all, if you’re managing to shed some considerable weight on account of your diet, who could blame you for wanting to carry on?

Reduce Bacterial Load

While bad breath from ketosis doesn’t come from poor oral hygiene, bad breath caused by high protein diets can be worsened by oral bacteria. As a result, effectively removing this can sweeten the breath in some instances.

Here, there are a number of options besides standard brushing and flossing. Studies suggest that cleaning the tongue is almost twice as effective as brushing alone at removing bad breath. As a result, investing in a tongue scraper can be a worthwhile exercise.

Drink Water

Simply sipping on water throughout the day isn’t just handy from a hydration perspective, but can also aid in the fight against bad breath. Drinking plenty of water serves to not only rid your mouth of excess food particles but can also effectively lubricate the mouth.

Reduce Protein Intake

If you’ve adopted a high protein diet to replace the carbohydrates you would normally consume, some experts claim that increasing the fat in your diet, while reducing protein, can also have a beneficial impact on bad breath caused by dieting.

Mask Unpleasant Odours

If your bad breath is being caused solely by ketone production, and you’re keen to remain on your diet, one of the few remaining solutions is simply to mask the smell as much as possible.

Consider the use of calorie-free and carb-free mints or gum, or use a flavoured oral preparation such as a mint-flavoured breath spray or mouthwash.

Be Patient

Lastly it’s worth pointing out that some dieters find that ketosis breath only lasts for a short period of time, usually measured in weeks. After this point, it seems that some people’s body’s become accustomed to their new fuel source, and the malodour disappears.

As a result, no matter which of the many solutions you experiment with, it is reassuring to know that ketosis breath may well clear up on its own with enough patience.