One Reddit user described the smell similar to that of bacon while another user has said that their new stench "kind of smells like fat is soaking into my sweat." Despite how common this side effect seems to be (people affectionately refer to it as "keto breath").
The side effect of fasting – unpleasant body odour
People who regularly fast are familiar with the typical fasting or diet odour, which is reminiscent of nail polish remover. The trigger for this unpleasant body odour is the partial reduction of body fat caused by a lack of carbohydrates.
Yet, science does show that going keto can change the odor of your breath and urine, making both smell like nail polish remover. That's because your body breaks down fat for energy instead of carbs. This process, the goal of a keto diet, is called ketosis.
This overgrowth in microorganisms can cause an infection known as bacterial vaginosis (BV), characterized by a strong fishy vaginal odor and discharge—which may be what some people are calling "keto crotch."
Itching, pain during sex, unusual discharge, discomfort, and bad vaginal odor are also experienced by those who get a keto crotch. Not just that, but according to Dr Gadoya, a keto diet puts so much load on our kidneys that it can lead to kidney failure as well.
During the first few months there was some extra smell stuff happening all over – crotch and otherwise. But, the good news is that it settles down and goes away after you've been keto for awhile.”
Increase your fat intake
Eating more fat can limit ketone stink creators like ammonia and acetone. A 2014 study found increasing dietary fat intake (and cutting back on protein) released less ammonia and acetone. All the more reason to get that extra guac!
Some describe keto breath as having a metallic taste in their mouth and a smell that's sweet, fruity or similar to nail polish remover. This is caused by the chemicals your body creates during ketosis, which are released from the body by exhaling.
The process of ketogenesis causes the presence of certain compounds which are not normally found in the breath. The main problem is that these compounds include acetone and isopropyl, causing the odour of cleaning alcohol to be present on the breath.
"When the body is in ketosis, it produces these chemicals called ketones," he explains. Ketones exit the body via your breath, and some through your sweat. One of these ketones is known as acetone, he says. Yep, you read that right — acetone, the same stuff that's in nail polish remover.
When a person eats a lot of protein instead of carbohydrates, their body uses protein and stored fat for energy instead of using carbohydrates as it would usually do. As a result, the ketone level in the blood will rise. When these ketones leave the body in the urine, the urine may smell sweet or similar to popcorn.
When we don't eat as regularly or as often, our bodies use an energy reserve—our fat. When fat is broken down, it releases ketone, which can produce an unpleasant scent. That scent is usually released from the body through our breath. Another culprit to bad breath—a dry mouth.
But if you're starved of carbs and turning to protein for most of your energy, your liver may not be able to handle all the ammonia your body produces. In those instances, your sweat becomes the vehicle through which your body jettisons all of the extra ammonia in your system.
UNAIR NEWS – Bad breath often becomes a nuisance when fasting. The body does not eat and drink for hours, which makes the mouth dry and triggers an unpleasant odor.
Strong-smelling foods like garlic and onion are notorious for causing bad breath – and they contain compounds, such as sulfur, that can be released from your pores and contribute to body odor, too. Other sulfur-containing foods that might add to that stinky smell include broccoli, Brussels sprouts, cabbage and kale.
As for how long keto breath lasts, it's temporary. It usually first appears within a few days to a week after starting the keto diet and lasts from several weeks to a few months, though if you go on and off the diet, your keto breath will come back.
"When you burn fat," Jaliman says, "your body produces a chemical that can make perspiration smell either like nail polish remover or fruity." This is not a problem for everyone, and affects some people in different ways. "The exact alteration to the natural body odor depends on a person's body chemistry," she says.
Drinking more water
This is because the body expels more ketones in urine rather than as a breath. By drinking water, people will produce more urine, which will help expel many of the ketones from the body. Drinking water may also help flush out bacteria in a person's mouth that could be causing bad breath.
A fruity odor to the breath is a sign of ketoacidosis, which may occur in diabetes. It is a potentially life-threatening condition. Breath that smells like feces can occur with prolonged vomiting, especially when there is a bowel obstruction.
If you eat between 20 and 50 grams of carbohydrates each day, it will usually take you two to four days to enter ketosis. However, the time it takes to enter this state varies based on several factors. It may take you a week or longer to get into ketosis.
If you have diabetes, a change in body odor could be a sign of diabetes-related ketoacidosis. High ketone levels cause your blood to become acidic and your body odor to be fruity. In the case of liver or kidney disease, your odor may give off a bleach-like smell due to toxin buildup in your body.
Your poop could smell different
Anecdotally, Weinandy says some patients say their bowel movements are more, uh, pungent. "I have quite a few patients who complain of it smelling worse," she says. That's because eating a lot of high fat foods makes stool move more slowly through the gastrointestinal track.
One of the 3 types of ketones our body produces when being fueled by fat is acetone — yes, that stuff in nail polish remover — but don't worry, this is a normal part of general fat metabolism and a sign that ketosis is working. Excess acetone is excreted through breath causing that fruity, nail polish remover smell.