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.

According to Medline Plus, a resource of the National Library of Medicine, 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 in the Nutrients journal describes low-carbohydrate, high-fat (LCHF) diets, such as the ketogenic diet, as promising in helping people lose weight, improve diabetes, reduce inflammation, improve cholesterol, supplement cancer treatments, and potentially increase longevity and 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, according to the National Library of Medicine (NLM), 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, per the NLM.

What Causes Keto Breath?

When your body breaks down fat for energy instead of carbs, it converts the fatty acids into chemicals called ketones, according to the National Library of Medicine. 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 Long Does Keto Breath Last?

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.

How Can I Get Rid of Keto Breath?

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.

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.

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.

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