Everything You Need to Know About Keto Breath
Changing your diet and increasing physical activity can help you reach your weight loss goals. But changing your diet doesn’t only involve a reduction of calories. It also involves modifying the types of foods you eat, which may cause certain side effects besides weight loss.
The ketogenic diet (or keto diet) is a high-fat, moderate-protein, low-carb diet designed to help you achieve ketosis. This is a natural metabolic state that occurs when you don’t receive enough carbs for energy and your body starts burning fat for fuel.
While the ketogenic diet and other low-carb diets can help you lose weight faster, “keto breath” is an unwanted side effect of ketosis. Here’s what you need to know about keto breath, including symptoms and how to get rid of it.
Symptoms of keto breath
Keto breath produces a distinct taste or odor in the mouth that’s different from ordinary halitosis or bad breath. Some people describe keto breath as having a metallic taste. In addition to a funny taste in the mouth, keto breath can be fruity-smelling or have a strong odor that’s similar to nail polish remover.
What causes keto breath?
To understand the cause of keto breath, it’s important to understand how metabolism works. Your body gets energy from a variety of food sources, including carbohydrates, fat, and protein. Typically, your body will break down carbohydrates or glucose for energy first, and then fat.
Since the ketogenic diet and other low-carb diets purposely restrict your intake of carbohydrates, your body is forced to use its fat stores for energy once you’ve depleted your glucose stores. Ketosis occurs when your body breaks down fat for energy.
Fatty acids are then converted into ketones, which are natural chemicals your body produces when you burn fat for energy. These include beta hydroxybutyrate, acetoacetate, and acetone.
Ketones are usually harmless and released from the body through exhalation and urination. Since acetone is an ingredient in some nail polishes, your breath smelling like nail polish remover in particular can indicate a state of ketosis. On the one hand, this indication that you’ve entered ketosis may be reassuring. On the other hand, it’s an unfortunate indicator.
How long does keto breath last?
Some people on the ketogenic diet never experience keto breath. For those who do, the odor can be troublesome. But keto breath is temporary.
You may notice a change in your breath within days or a week of starting a low-carb diet. However, the odor will subside as your body adjusts to a lower carb intake. This might take a couple of weeks, and there are a few things you can do to freshen your breath during this period of time.
Home remedies for keto breath
Here are a few simple tips to reduce bad breath while your body adjusts to a low-carb diet.
1. Increase your water intake
Along with exhalation, your body flushes acetone and ketones from your system through urination. Stay hydrated and sip on water throughout the day to increase urination. This helps flush ketones from your body and improves your breath. Drinking more water may also help with your weight loss goals.
2. Eat less protein
While protein is important on a low-carb diet, eating too much protein can worsen bad breath. As your body breaks down protein, it produces ammonia. This is another byproduct of metabolism that’s eliminated through urination and exhalation. Ammonia can create a strong odor on the breath, too.
Decreasing your protein and increasing your consumption of healthy fats (avocados, nuts, olive oil) may improve your breath without forcing you to go off the diet.
3. Practice good oral hygiene
Brushing your teeth twice a day and daily flossing may not completely eliminate keto breath, but these practices can reduce the odor coming from your mouth.
Bacteria can accumulate in your mouth and in between your teeth when you don’t brush or floss regularly. Since bacteria also triggers bad breath, poor dental hygiene can worsen keto breath.
4. Mask odor with mints and gum
You may want to suck on mints and chew gum until your body adjusts to a low-carb diet. Make sure you choose sugar-free mints and gum.
Be aware that some chewing gums and mints contain a small amount of carbohydrates. If you chew or suck on several pieces throughout the day, this could increase your daily intake of carbs and kick you out of ketosis.
5. Bump up your carb intake
Slightly increasing your carbohydrate intake can also eliminate keto breath. If you want to remain in a state of ketosis, only increase your daily amount of carbohydrates by a small amount.
Let’s say you’re eating 15 grams (g) of carbohydrates per day. Try increasing your intake to 20 g per day to see if your bad breath improves. Then, use a ketone breath analyzer to measure your ketone level. Monitoring your ketone level is key to knowing whether you’re still in ketosis after increasing your carbs.
6. Be patient
Sometimes, you can’t get rid of keto breath. So, if you’re committed to a low-carb diet to lose weight, be patient and allow your body to adjust to its new fuel source. Your bad breath will improve after a couple of weeks.
Can you prevent keto breath?
Keto breath is a side effect of ketosis and a low-carb diet, and there doesn’t appear to be a way to prevent the odor. What you can do, however, is use a ketone breath analyzer to determine the most carbs you can eat without being kicked out of ketosis. If you can add more carbs to your diet and eat less protein, this might be enough to keep your breath fresh.
If you notice keto breath and you’re not intentionally on the ketogenic diet or a low-carb diet, eating more carbs can quickly kick you out of ketosis and eliminate bad breath. For example, if you’re currently consuming 50 g of carbohydrates per day, up your intake to 100 g per day. You can increase your amount of physical activity to compensate for the added carbohydrates.
Why Low-Carb Diets Cause Keto Breath
Bad breath is one of the possible side effects of a low-carb diet, such as the Atkins Diet, South Beach Diet or Dukan Diet. Known as ketosis breath, or simply keto breath, the condition is often accompanied by a foul taste in the mouth. Symptoms like these can be distressing, but there are things you can do to overcome them without undermining the goals of your diet.1
There are many causes of bad breath. However, with low-carb diets, there are two primary culprits: ketosis (the metabolic state achieved with a low-carb diet) and protein metabolism.
One of the body’s primary sources of energy is glucose. Glucose is created when the digestive tract breaks down carbohydrates from complex sugars to simple glucose molecules. When you reduce the number of carbs you eat, your body has to find alternative fuel sources (namely fat) for energy—a metabolic state known as ketosis.
When the body breaks down fatty acids, it creates a byproduct known as ketones. Common ketone bodies come in three forms: acetoacetate, beta-hydroxybutyrate, and acetone. These ketone bodies are regularly removed from your body through urination and exhalation.2
If you’re on a low-carb diet, your body is relying more on fatty acids for energy because you aren’t eating as many carbohydrates. As your body uses up more fat, more ketones will be released as a byproduct of the metabolic process at work. The excessive accumulation of ketones in your body can contribute to bad breath.2
However, the ketones you exhale have very distinctive scents—most of which are unlike what you would experience with everyday bad breath (halitosis).
Changes in your diet can also trigger changes in your breath. With a low-carb diet, the sudden switch from carbs to proteins alters how your body metabolizes food.
The breakdown of protein in the body creates ammonia. A sudden surge in dietary protein will only amplify this effect, increasing the amount of ammonia in both your stomach gases and urine.
Keto breath varies from person to person but is generally not the same as halitosis. The bad breath most of us experience from time to time is caused by bacteria in our mouths. When these bacteria start to break down the food we eat, they create volatile sulfur compounds (VSCs).4 Usually, these compounds have a sulfurous odor (similar to rotten eggs).
With keto breath, characteristics of the smell vary based on which byproducts of protein and fat metabolism are produced. For example:
- Acetoacetate and beta-hydroxybutyrate can cause your breath to smell sweet and fruity. Some people describe the odor as similar to bruised or rotting apples.
- Acetone on the breath creates more of a resiny smell (like nail polish).
- Excess protein metabolism can cause both your breath and urine to have an aroma of ammonia.
In most cases, keto breath disappears on its own—though it may take several weeks to a month. If you’ve committed to a low-carb diet, here are a few ways to mitigate the symptoms of keto breath while your metabolism adjusts.
- Drink more water. Aim for no less than eight 8-ounce glasses of water per day. This not only helps flush excess ketones and VSC from your body, but it also aids in digestion and prevents constipation.
- Change the balance of proteins you consume. While this is a trial-and-error process, a change of protein sources—say, from chicken to meat or meat to fish—can sometimes alter which ketone bodies are being produced (mainly by the types of fatty acids begin broken down).
- Increase fat intake. Research suggests that increasing fat while reducing protein consumption can help minimize both acetone and ammonia emissions.
- Don’t undercut the carbs. Don’t be overzealous and cut out more carbs than you need. The South Beach Diet, for example, is not as strict on the carb count as the Atkins Diet. Neither, however, aims for a zero-carbs policy. If you suspect you’ve gone overboard on carb cutting, try increasing your intake of healthy carbs within the prescribed limit.
- Mask your breath. Try natural breath fresheners (such as mint, parsley, cloves, cinnamon, or fennel seeds) or breath capsules made from parsley oil or chlorophyll.