Keto Breath Is a Common Problem for Low-carb Dieters

How to get rid of the smell without going off keto.

If you've ever been on the keto diet, you might have noticed that your breath had a different odor for the first couple of weeks. "Keto breath" is a common side effect of eating high-fat, low-carb meals. And while it might be very unpleasant, it's actually a sign that your body is in ketosis.

Ketosis is a normal metabolic process that occurs when the body uses fat for energy instead of carbohydrates, resulting in higher blood ketone levels. Ketosis can occur in people who eat a low-carbohydrate keto diet to lose weight.

When done right, the keto diet (or keto) has a lot of benefits, including weight loss and improved cognitive function. A 2021 study describes low-carbohydrate, high-fat (LCHF) diets, such as the ketogenic diet, as promising in:

  • Weight loss
  • Improving blood sugar levels
  • Reducing inflammation
  • Improving cholesterol
  • Supplementing cancer treatments
  • Potentially increasing brain function

Unfortunately, with these potential benefits comes one potential drawback: keto breath. It's not the only body odor keto might cause; some keto followers have reported a foul vaginal odor after starting the plan.

Here's everything you need to know about keto breath, including the most important thing: How to get rid of it.

What Are the Symptoms of Keto Breath?

Ah, the smell of nail polish remover. Seriously, that familiar post-manicure odor is pretty close to keto breath, said Cynthia Sass, RD, Health contributing nutrition editor. In fact, people on a keto diet can even have a false positive breath alcohol test (though this is rare).

Along with that smell might come a lingering metallic taste in your mouth. This is the most commonly reported keto breath, but some followers say they get a whiff of something different, like more of a fruity odor.

What Causes Keto Breath?

When your body breaks down fat for energy instead of carbs, it converts the fatty acids into chemicals called ketones. Ketones are chemicals like acetoacetate, beta-hydroxybutyrate, and acetone.

The body then disposes of the ketones through both exhalation and urination.

"One type of ketone, acetone, is an ingredient in some nail polish removers, which is why your breath may smell like this familiar scent," said Sass. As unpleasant as the smell may be, it's an indication that your body is in ketosis.

How Can I Get Rid of Keto Breath?

The good news is keto breath is only temporary. "It's more noticeable at first because of the big shift the body is going through," said Sass. Within a few weeks, as your system adjusts to eating way fewer carbs, your breath should return to normal.

Drink Water

Thankfully, there are a few things you can do to get rid of keto breath. First, said Sass, is drinking more water. Remember, one way your body gets rid of ketones is through your urine. So the more you hydrate, the more you'll pee, and the faster those ketones will leave your system.

Eat Less Protein

You can also try eating less protein, said Sass. When the body metabolizes protein, it produces the chemical ammonia—another reason your breath may become more pungent on keto.

Eat Saliva-Producing Foods

If your mouth tastes like metal, try chewing on fresh mint and eating foods that increase saliva production, like celery and lemon, advised Sass. Extra saliva helps clean out lingering bacteria that can worsen the odor. You can also try upping your carb intake just a tiny bit, by about five grams or so, which will lower the level of stinky ketones your body produces. (A breath analyzer can help you find the highest number of carbs you can eat while staying in ketosis.)

Oh, and don't forget to brush your teeth more frequently while you're at it.

A Quick Review

Smelly breath is unfortunately a common side effect of the keto diet. If you notice a smell that is fruity or similar to nail polish, thats a sign that your body is in ketosis. To combat the smell, try brushing your teeth, staying hydrating, eating more protein, or just wait it out—it's only temporary.

Was this page helpful?
4 Sources uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Library of Medicine. Ketones in blood.

  2. Dowis K, Banga S. The Potential Health Benefits of the Ketogenic Diet: A Narrative ReviewNutrients. 2021;13(5):1654. Published 2021 May 13. doi:10.3390/nu13051654

  3. Masood W, Annamaraju P, Uppaluri KR. Ketogenic diet. In: StatPearls. StatPearls Publishing; 2022.

  4. Dhillon KK, Gupta S. Biochemistry, ketogenesis. In: StatPearls. StatPearls Publishing; 2022.

Related Articles