The benefits of keto are always spoken about; and trust me, there are plenty! However, there are some side effects of keto too, which you should know about if you are going to embark on a keto way of living. The common side effects of keto are easy to overcome with a few simple tricks which I will take you through below.
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Recently, we wrote an article on the main benefits of keto, check it out here. There are numerous benefits of keto, however, it’s only fair to go through the potential common side effects of keto.
I’m not willing to call these the ‘negatives’ of keto, as none of them is lasting and all can be overcome. So, in my book, they are not side effects, merely slight inconveniences that need to be addressed. All of them can be overcome.
In this article, I will go through the common side effects of keto, how to spot the symptoms, understanding what the causes are and how to overcome the side effects. With these top tips, you will be able to get on with your keto journey, lose weight, and feel great!
Probably the most common side effect of the keto diet is keto flu.
If you have done any research on the keto diet, you will no doubt have heard of keto flu. The Keto Flu can be anything from the list below;
- Feeling nauseous
- feeling of lethargy
- Difficulty focussing aka ‘Brain Fog’
Some people get none of these symptoms, others get one or more of the symptoms to varying degrees.
Why would anybody do keto? Having read the symptoms of Keto Flu, I can understand why you would ask why anybody would continue with keto.
The reality is that not everybody gets the keto flu; I know I haven’t personally. For others, these symptoms can last from a day, up to a week.
Once your body gets used to your new way of eating (keto) and adjusts, the symptoms will go away.
I liken the keto flu to buying a new pair of gorgeous shoes…. bear with me here.
You see the shoes on the shelf, you can see all the possibilities of how they can fit into your life, full of hope, you bring them home, and you put them on.
They look amazing…..
However, after a few hours, they start hurting your feet, and you want to give up on them and put them back away in the box…but you don’t, you keep persevering with them.
Over their next couple of outings, the rubs and niggles become fewer. After no time at all your gorgeous shoes are like slippers and you can’t even remember a time when they gave you any discomfort! Soon, you cannot remember life without them!
After that long analogy – keto is the same! It is going to take your body a bit of time to adjust, but stick with it and you’ll soon get there!
How to get over the Keto Flu
This will pass with time. You do not need any supplements on keto – and be wary of anybody telling you otherwise. That having been said, some people do use electrolyte supplements to overcome the keto flu.
Keto Breath / Halitosis
This is one of the most embarrassing side effects of keto as it is noticeable by others. The bad breath is a result of the chemical reaction that is happening in your liver when ketones are produced and you go into ketosis.
This only normally lasts for a week after you go into ketosis.
I have personally suffered from this every time I’ve dropped out of ketosis and have had to get my body back into it.
It is only short-lived and can be kept at bay with sugar-free chewing gum and/or mints! I have also been known to keep mouthwash in my desk drawer at work, just in case I’m, unexpectedly called into a meeting!
Keto Pee / Ketones in Urine
This isn’t one to worry about, however, as discussed above, when ketones begin being produced by the liver, a by-product of chemicals is produced.
These are expelled by the body; however, the body can get rid of them. This may be in the breath or in the urine. Your urine may smell stronger than usual for a short period. As discussed above, this is short-lived whilst your body adjusts to keto, don’t panic!
This is linked to the keto pee and keto breath above. The body needs to get rid of the chemicals that are produced in the liver as a by-product of going into ketosis.
These are expelled by the body however they can. This may be via sweat. You may find that you are particularly sweaty for a few days, and this will be a different and usually stronger smell than normal.
Again, be reassured that this only lasts for a few days, before your body returns to normal.
Check out or article for more about body odor on keto.
Yes, I am blushing as I type this!
You may find your crotch has a ‘fishy’ smell.
Eek, I know this sounds dramatic. A change in diet as dramatic as this will change the pH of the body, including your vagina.
This may alter the odor of your vagina. Again, as will all of the above, this is only short-lived and as the body adapts to being in ketosis, your body will re-balance its pH and your vagina’s odor will return to normal.
Lack of Energy / Lethargy
People starting out on a keto way of eating often complain about a lack of energy as a side effect. As with the keto flu, this is short-lived.
Again, this is only an issue whilst your body gets into ketosis (1-5 days depending on the individual). This makes sense when you think about the science behind this.
As your body has been used to burning sugar (remember carbs are sugar!), suddenly its supply has been taken away from it. It will burn what is there, then it is waiting for its next ‘hit’.
Whilst it is waiting for this hit, it doesn’t have anything to burn, so you will become tired, as energy isn’t being produced.
However, despite being tired, you may experience keto insomnia.
Once your body has realized that the sugar (carbs) supply has gone – but there is ample fat to burn, it will adjust to doing this. Then you will get your energy levels back.
If you are an avid gym-goer/exerciser, you may want to have some lighter sessions during your first week of keto.
Once you are in ketosis, you will be back on form, and potentially even better!
As much as none of us like to discuss this, it’s only fair that I pre-warn you!
This is a tale of two sides.
Initially, most people find that they have loser bowel movements as their body adjusts. However, as you move into a keto way of eating the opposite occurs.
People can end up constipated.
This is normally due to people not getting enough fiber in their diets. Keto is high in fat and low in the foods which are high in fiber, such as bread and fruits, etc. It is the fiber in our diets that keeps us regular.
This can easily be addressed by eating foods such as chia seeds, which are naturally high in fiber. I regularly (no pun intended) add chia seeds to my yogurt for breakfast, into my smoothie, on my salads or in my keto baking.
You may become exceptionally thirsty
As you are transitioning into ketosis, the elevated levels of ketones may disrupt your overall electrolyte levels.
Electrolytes regulate the fluid in your body.
A reduction in electrolytes causes the kidneys to release water and salt. This can result in two things; firstly, you may urinate more, the knock-on effect of this being that you will feel dehydrated and want to drink more.
This is easily overcome by doing just that; drinking more! Check out our guide to drinking water on keto, it’ll talk you through how much you need to drink in order to feel hydrated.
Cramping Leg Muscles
Cramping leg muscles can be a sign that you need to drink more water. This links in with the dehydration above, due to the reduction in electrolytes in the blood.
Again, it is not something that you need to be concerned with; just get yourself a snazzy water bottle to encourage you to drink.
Elevated heart rate
A lot of people moving onto a keto diet will experience heart palpitations (racing heartbeat) in the early days of being on keto as the body transitions into ketosis. This is a common side effect of being dehydrated.
If these continue after a couple of weeks of eating a keto lifestyle, you may need to try and increase your carb intake slightly, if it continues beyond this, seek medical advice.
Alcohol tolerances reduced
Yes, you will likely become a lightweight! Although this may be a bonus for the purse, keto hangovers are a real thing too!
This is due to depleted glycogen stores in the body. It is these glycogen stores that normally absorb alcohol.
Instead of the alcohol being absorbed, it travels straight to the liver where it is metabolized. This is why you will feel drunker, and quicker.
Check out our guide for drinking alcohol on keto.
It may be that you start to feel hot when you move over to keto. This is due to a number of different metabolic processes which are going on in your body.
Don’t worry though, this is short lived.
Will I get all of these keto symptoms?
Everybody will have a different experience with keto and transitioning into ketosis.
Having been around the keto community for around a decade, I can tell you that it would be very unusual for somebody to experience all of the above symptoms.
Most people will experience 1-2 of the above keto symptoms. I have known some people who do not get any of the above symptoms.
What were my symptoms when going into ketosis?
I don’t know whether I got away with transitioning into ketosis lightly or not. For me, my main symptoms were that I had a real body odor issue.
Yes, this was embarrassing! It was about 3 days into eating keto that it started. The first day I noticed it, it was mid-morning at work. I went into a mild panic that I’d forgotten to put my deodorant on.
Then I remembered that I had read about this being a side effect of keto. There were mixed feelings at this time. I was glad that I was transitioning into ketosis, but didn’t want to be ‘that person’ in the office that smelt!
The next day I took body wipes, deodorant, and perfume and when I noticed the smell, I did a toilet run and sorted myself out! The good news? This only lasted for around 2.5 days. After this time, the chemical imbalance in the body had sorted itself out and all was back to normal.
Yes, I got this!
I’m almost too embarrassed to tell you all about this!
A smelly crotch is no small matter as a lady!! I’m not going to lie; this was not a pleasant experience. Down below was smelly for around 3 days. Just to put this in perspective, if I was wearing jeans, I couldn’t notice.
If I was wearing a skirt or a garment thinner than jeans, I could smell me. I don’t think it was bad enough that anybody else could smell it. I certainly wasn’t about to ask!
This was a very manageable symptom!! For the first week of eating keto, I was extremely thirsty. As somebody who already drinks a lot of water / juice, I didn’t anticipate that this would be an issue for me.
If I remember rightly, it was a night of day two or eating keto, I was laid in bed on the night and I felt like I hadn’t had a drink for days, I was parched! I soon got into the routine of refilling my water bottle many times a day, this was in between the cups of green tea and coffee!
I got all of the above the first time that I went into ketosis. Since this time, I have fallen out of ketosis, (I am human after all!), each time I’ve gone back into ketosis after this, I have had one of each of the above, but not all three at the same time. Thankfully, I have never had to deal with keto flu symptoms personally.
Is the keto diet for everyone?
Like with any way of eating, keto is not going to be for everybody. All that I can tell you, is that all of my friends that have tried keto, have stuck with it.
The best thing to do is give it a go!
Commit for a minimum of 3-6 months and see if it is for you.
Check out our article for the main reasons that people quit keto, to make sure this is not you.
How long do keto side effects last?
As discussed above, for me, the worst of the symptoms have not lasted more than a few days. People I know have said that symptoms like the keto flu can last up to a week.
As with everything diet-related, all of our bodies are different, and they all react in a slightly different ways. This makes it impossible to give you a definitive as to what symptoms you may/ may not get and how long they will last.
In summary; yes, there may be some side effects of keto, they can be mild to moderate, but whichever way, the symptoms can be overcome and will be short-lived.
Share with the community your keto side effects and the best way to get over these in the comments below!