Why Does the Keto Diet Make Your Breath Smell so Freaking Foul?

Keto breath is…exactly what it sounds like. The diet can basically make your breath smell really, really foul, thanks to all of those delicious, good-for-you healthy fats you’re eating. “When you start the ketogenic diet, your liver begins breaking down fatty acids and turning them into ketones,” explains Sara Gottfried, MD. (In case you’re a keto newbie, ketones are a form of fuel for your cells that come from fat.) “Then your body uses a portion of the ketones and the rest are excreted in breath and urine,” she says. Most people compare the distinct smell to rotten apples, Dr. Gottfried adds.

Fortunately, Dr. Gottfried says keto breath doesn’t last forever—it’s just an unfortunate part of your body adjusting during that transition period. “Keto adaptation takes about 10 days in healthy people, and longer in people who are insulin resistant—in my practice, up to six weeks,” she says. After that, your body—and breath—should get back to normal.

But thankfully, you don’t have to just live with a smelly mouth in the meantime. Getting rid of keto breath starts with being extra-intense about your tooth-brushing routine. “Floss twice a day, scrape your tongue, and brush for two to three minutes twice a day,” Dr. Gottfried says.

Something else she says will help is drinking plenty of water and upping your intake of electrolytes (which you can get from bone broth, salmon, and leafy greens), which can help give your body a boost and potentially shorten the rough keto transition period.

So when things really start to stink, just remember that keto breath (like all bad things) is simply temporary. And hey, there’s always gum and mints.

If you’re just starting the ketogenic diet, beware of these five common mistakes many people make. Plus, the verdict on if it can help with anxiety.