10 Signs You’re In Ketosis

Starting a Keto Diet can be frustrating at first, because you want to know when you are in Ketosis. Your body will enter into ketosis once it has used up all of its glycogen stores. This can take 7 days or more.


The problem is that most people don't know how to tell if they have reached this stage or not, but are desperate to know.

10 Signs you are in Ketosis - Forever Keto

Why? Because we are all impatient by nature and want to know that this new thing we are doing is working. It’s part of our desire for instant gratification.


Sure, you can test at home with Ketone Strips and Ketone Meters, but can you tell you are in ketosis without testing?


There are signs you can look out for so you know when you’re in Ketosis. Not everyone has the same experience though, so I’ve put together 10 signs to know you're in Ketosis as soon as possible!


1. Keto Flu

If you are in ketosis, one of the first signs that your body is producing ketones is lethargy, a feeling like you’ve suddenly hit a wall. It can sneak up on you quickly, so be prepared.


Commonly referred to as Keto Flu this can feel like you are wading through syrup, making everything more challenging, whilst Brain Fog makes thinking clearly hard. Sounds terrible, right?

Luckily this phase passes quickly and as long as you keep to your Keto Diet, should only happen once. Remember this feeling, because that’s going to help you stay on track and not ‘fall off the wagon’ on your Keto journey.


What can you do about it?

Drink plenty of water - A Keto Diet requires you to drink more water generally, but in the initial phases your body flushes out extra water as it depletes glucose, which can leave you de-hydrated.


Take electrolytes - When you lose all that extra water, you flush out essential electrolytes your body needs to function, like Sodium, Magnesium and Potassium. Being prepared with electrolyte drinks or supplements to help you through this initial phase is vital.


Rest and be patient - you are asking a lot of your body at this stage, so give it a little time to adjust and it will reward you. Most people experience a ‘Woosh’ of weight loss during this phase.

2. Impaired Physical Performance

Alongside Keto Flu, you may notice that you struggle to work out as hard, or the stairs seem insurmountable. This physical challenge happens as the energy stores in your muscles - in the form of glycogen - is depleted.


It only lasts for a short time and you just need to ride it out. Take time for self care, meditate if that’s your thing, don’t push yourself too hard through this phase, as it will just make you feel worse.

3. The Keto Woosh

The Keto Diet is well known for its ability to produce rapid weight loss results for many. This Woosh of weight loss comes as you hit ketosis and the extra glycogen in your body is flushed out, taking with it all the water your body uses to store it. You may experience weight loss of several pounds over a few weeks - I was losing 3-4lbs a week in the first few weeks, my husband more like 6-8.

Don’t be surprised if, once your body has flushed out all that glycogen and extra water, you go up a few pounds as it adjusts. I know it can be demoralising to have lost weight and then see it show up again, but celebrate the net weight loss result, and know it’s just the beginning.

4. Keto Breath


When you enter ketosis, the extra ketones can be carried on your breath in the form of acetone. You know, that strange sweet smell that nail varnish remover has? It’s like that. Some people experience a stronger metallic taste, and for others it’s more fruity, but pretty much everyone will tell you they become conscious of bad breath.

Again, this passes quickly for most people, lasting only for a few days when they first enter ketosis as the body adapts. It’s another one to store away in your memory bank, as you don’t want to have to go through it again if you don’t have to.

If you are concerned about it, and staying away from people who might notice is not an option, there are a couple of things that can help.


Drink more water - yes, I know I sound like I’m on repeat, but you’ll get used to it. Water is now your best friend. You can also add things like ginger root, lemon and mint leaves to your water as they have pleasant natural smells as well as being beneficial to your body - so a win-win.


Clean your teeth - not obsessively, but your toothpaste contains ingredients that help counter bad breath.


Use mouthwash - for the same reasons as above. These products are designed exactly for this job.


Drink water for Keto Flu and Keto Breath - Forever Keto

5. Ketones in your Blood & Urine


Around the same time you might experience Keto Breath, those same ketones will start to show up in your blood and urine. There really isn’t any way to know this unless you test with ketone strips or a ketone meter though.


6. You’re not Hungry

As your body gets used to a high fat diet, you’ll find you are satisfied (satiated) more quickly and begin to feel less hungry between meals.


In the beginning you may struggle with this loss of appetite, but once you settle into your Keto routine, you’ll come to understand that your body will tell you when it needs more fuel and you will become less of a slave to the concepts of ‘3 meals a day’ and more attuned to eating on a schedule that suits you.


You may find that you were always a breakfast person, but suddenly you don’t want to eat in the morning. If you were an after dinner snacker, you’ll be surprised to find that your dinner leaves you feeling full and that desire to nibble just goes away. Before Keto, I literally used to snack as I cooked dinner, and I could never have imagined that I would not have breakfast. Now my first meal is ‘brunch’ - typically bacon, egg & avocado - and before I have that I’ve done half a days work and my daily 5 mile walk.

7. You Suddenly have More Energy


Once you have passed the Keto Flu phase, it’s common to find you have a sudden surge of energy. This still happens for me when I transition between Lazy and Clean Keto. I go from that person who hides under the bedcovers for as long as possible in the mornings, to someone who’s up, awake and functioning at 6.30am. I never thought that would be me.

This surge of energy is your body’s way of letting you know that it’s becoming fat adapted and can now access the stored fat in your body as an energy battery.

8. Mental Clarity

Ketones provide a far more efficient fuel for your brain, allowing it to function more optimally, brining mental clarity.

It has been suggested that this increased energy may allow the brain to ward off stressors which cause diseases resulting in impaired cognitive function, although more research is needed to verify this.


9. Keto Insomnia


As you enter ketosis for the first time, all the extra energy and mental clarity can lead to Keto Insomnia. My experience of this has been waking up at 3 or 4 am and just not being able to get back to sleep. I tried sleep mists and lavender pillows. I even tried a white noise machine, until I realised I was awake because I just wasn’t tried. So I got up and got things done!

When you label something as insomnia, it makes it sound bad, but in this case it’s your body telling you that it’s rested and ready to go. It doesn’t last forever, and may come and go on occasion as part of your Keto Lifestyle, so embrace it rather than fighting it.

If it becomes an issue and you are not feeing rested, you can try things like taking magnesium citrate at night and using essential oils to make you more receptive to sleep.

10. Digestive Issues


One of the many benefits of a Keto Diet is its beneficial effects for digestive issues, but in the beginning you may find it, um… makes you go! As your stomach gets used to a higher fat intake and your digestion is stimulated by this new way of eating, you may find that you experience loose movements for a few days. Remember you are flushing all that extra stored water out of your body and it has to come out somehow!

Ok, so all that makes starting a Keto Diet somewhat dreadful, but any significant change requires some effort. Now you know what to look out for, you’ll be able to spot the signs and know when you’re in ketosis without having to test for it. But I bet you do - pretty much everyone does!


How can you Cope with Transitioning into Ketosis?

Hopefully you picked up on drinking more water?! Plan for it. Too many people rush into a Keto Diet without preparing and that’s just asking to make it harder. If you prepare in advance, follow a good Keto Diet plan, have your grocery shopping done and stock up with electrolytes, you’ll be ahead of the game.


Chose the right time. If you have a competitive sports event coming up, are about to do something stressful like start a new job or move house, or if you are already under the weather, it’s not a great time to put extra stress on your body.

I’m not saying that as an excuse to put off starting, but just as words of caution so you don’t set yourself up to fail by making it harder than it needs to be.


You can join Facebook groups for moral support - although some of them can be quite judgemental! - our Forever Keto Facebook group is lighthearted and keeps things real. You can also ask me questions through the form at the bottom of this page. I’m more than happy to help.