It's no surprise the keto diet is so popular — it's helped countless people lose weight, gives you more energy, and can lower blood sugar levels. And while the keto diet does come with some negative side effects, none is more embarrassing than keto breath. Unlike halitosis, or regular bad breath, keto breath is its own phenomenon where people who are on keto or another extremely low-carb diet experience breath that smells like acetone or ammonia.
Fortunately, although it's unpleasant, keto breath can be treated. We tapped some dentists, who explained why this happens and how you can treat your stank breath.
Why Does the Keto Diet Give You Such Bad Breath?
You may think the bad breath comes from eating all that bacon and cheese. And while those certainly don't help, it's not the food you're eating that causes such a foul odor radiating from your mouth — at least, not directly.
On the keto diet, the goal is to get your body into a state of ketosis. By eating more fat and so few carbs, your body starts to burn fat for fuel once it runs out of its carbohydrate reserves. As your body burns through its fat stores, it produces ketones in the liver. Once your blood ketones reach a certain level, you are in ketosis. When your body releases ketones, they leach into your urine and breath; hence, the foul smell.
"The specific culprit is acetone, a ketone that exits the body in your urine and is also released in your breath, creating a distinct odor that has been described like rotten fruit or even metallic," dentist Chris Kammer, DDS, founder of American Academy For Oral Systemic Health, told POPSUGAR.
And it's not just the ketones that are causing your bad breath; if you're eating a lot of protein, that could also be a contributing factor, explained dentist Kyle Stanley, DDS, a professor at the University of Southern California School of Dentistry.
"Classic bad breath is caused by volatile sulfur compounds, or VSCs," he told POPSUGAR. "These VSCs are caused by the breakdown of protein that sit on the back of the tongue and smell like rotten eggs." The VSCs combined with the acetone make for one nasty and embarrassing odor.
Is There Anything You Can Do?
If you're doing well on the keto diet and enjoying all the other benefits, you can still stay in ketosis and treat your bad-breath situation. One way is to stimulate the saliva production in your mouth with natural xylitol, which is a sugar-free compound. Dr. Kammer recommends the Spry Dental Defense brand of xylitol mints, gum, and mouthwash.
He also suggests drinking plenty of water throughout the day to give your mouth enough saliva, and also munching on herbs, especially parsley, clove, and cinnamon. Of course, it's important to keep up with your oral hygiene, which includes brushing at least twice a day, flossing, and using mouthwash.
Otherwise, you can get your body out of ketosis and start eating more carbs again. It's up to you whether or not chewing minty gum and swigging mouthwash throughout the day are worthwhile.