Why Your Breath Stinks on Keto, and What to Do About It

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Keto breath is real — but there are ways to de-stink yourself.
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Trying the keto diet? You may have noticed a super stinky side effect. Yup, we're talking about that embarrassingly bad breath. "Keto breath" is an unexpected — but totally common — consequence of the low-carb diet.


And while your breath may reek like nail polish remover (more on this later), "it's also a sure sign that you are primarily metabolizing fat," which is the goal of the keto plan, Amy M. Goss, PhD, RD, assistant professor at the University of Alabama at Birmingham's Nutrition Obesity Research Center, tells LIVESTRONG.com.

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Below, Goss explains everything you need to know about this keto-related malodorous mouth issue, including how to shrink the stink.

Why the Keto Diet Gives You Bad Breath

"The ketogenic diet is very low in carbohydrate content, so it lowers the glucose response to a meal and reduces secretion of the hormone insulin," Goss says. "When insulin is low, there will be a switch from glucose to fat as the primary metabolic fuel source."

In other words, when you're in ketosis, your body gets energy by breaking down fatty acids. And this process results in byproducts called ketones.


"Ketones that are not used by tissues will be excreted in the urine and breath," Goss says.

One kind of ketone, acetone, which is the same chemical found in some nail polish removers, can be excreted in the breath, she says. Which is why your breath may remind you of getting a manicure.

How Long Does Keto Breath Last?

Luckily, not forever. "Over time, the tissues in the body can become more adapted to using the ketones as a fuel and less will be excreted," Goss says. That means less acetone emitted and less foul, fiery breath.


But keep in mind, the length of time it takes to adjust will vary from person to person, Goss says.

4 Ways to Combat Keto Breath

In the meantime, here are a few strategies to keep keto breath at bay.

1. Practice Good Oral Hygiene

"The best way to deal with this is to maintain good oral hygiene," Goss says.



Brush twice a day (including your tongue) and floss daily. Mouthwashes that contain an antibacterial ingredient like cetylpyridinium chloride can help too.

Try These Mouthwashes

Colgate Total Alcohol-Free Mouthwash ($4.62 at Walmart)

Crest Pro Health Multi-Protection Mouthwash ($5.79 at Walgreens)

Cepacol Antibacterial Multi-Protection Mouthwash ($6.59 at CVS)

2. Chew on Sugarless Gum

"Use sugar-free gum or mints if the smell is too problematic," Goss says.


Sugarless varieties containing the natural sugar alcohol xylitol may also impede some bacteria, which can cause odors, and stimulate the flow of saliva, which helps clear away food debris from your teeth.

Try These Gums

  • Mentos Pure Fresh Sugar-Free Gum ($3.12 at Walmart)
  • Pur Sugar-Free Gum ($7.54 at Walmart)
  • Trident Sugar-Free Gum ($1.12 at Walmart)

3. Drink More Water

Sipping on H2O can help wash away food particles and hinder bad bacteria from growing in your mouth.

4. Try Natural Breath Fresheners

Chew on fresh mint or add it to your water and tea.



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