How to Fight Tiredness on Keto Diet

Low Carb Keto Diet Tired Exhausted FightHave you just started a low-carb or Keto diet – and feeling utterly exhausted all the time? Tiredness is a common low-carb diet side effect, especially for first-timers. That’s because moving from carbs to fat as your main fuel source is a huge change.

Your metabolism needs time to adjust. Until it does, you might feel tired, and experience low-carb flu symptoms. The duration of this adaptation period varies for each individual – it can last from several days to a couple of weeks. Sometimes fatigue can strike at later stages too.

Here are some tips on how to fight tiredness and improve your energy levels while sticking to your diet.

1. Eat enough fat

Once you cut your carbs, dietary fat becomes your main source of energy. If you cut the carbs and don’t add enough fat to make up for it, then fatigue is inevitable. So make sure you are getting the right amount of fat.

On any low-carb high-fat (LCHF) diet, fat should provide most of your calories – about 60%-80% from total (if you are not on Keto, check the fat intake guidelines of your chosen low-carb plan).

For beginners, this can be quite hard. Our perception of fat has been destroyed by years of negative propaganda in the media.

You need to make a conscious effort to include extra fat to your diet. Otherwise, you could fall behind. Not enough fat means less fuel for your body, and less energy.

Here’s how to crank up the amount of fat in your diet:

  • Eat fatty meats (for example, sirloin or rib-eye steak, pork belly, lamb neck, bacon, sausages), poultry with skin, fatty fish like salmon and mackerel
  • Jazz up your cooked vegetables and salads with plenty of butter and high-quality vegetable oils (coconut oil, avocado oil, flax oil, cold-pressed olive oil)
  • Use full-fat cream (or maybe even butter!) in your tea and coffee
  • Choose snacks with some fat in them, for example, cheese, macadamia nuts, brazil nuts, avocados
  • Use high-fat sauces (e.g Bearnaise) and condiments (e.g. mayonnaise) – preferably home-made

More tips on how to eat more fat

2. Eat regularly

A low-carb diet is satiating, so you won’t get hungry as much. Great news! Especially if other types of diets used to leave you ravenous.

But if your calories intake drops too low, you are likely to feel tired. This is especially true at the beginning of your diet, as your metabolism is not yet fully adapted to processing fat for energy.

So if you are feeling fatigued, don’t skip meals. Have three meals a day, with a decent amount of fat and protein.

Some dieters combine low-carb with intermittent fasting. This can work really well – but only after you are fully keto-adapted, which can take 1-2 months. So if you have just started your diet, it’s better to play it safe and eat regularly.

Dr Atkins recommended a maximum of 6 waking hours between meals on the initial low-carb high-fat phase of Atkins. This is a good rule to bear in mind for all LCHF dieters.

3. Eat clean

Natural, nutritious whole foods are recommended for all types of diets. They are also key to making your low-carb diet a success.

Don’t waste your carb allowance on sweeteners or chemical-filled sugar-free Frankenstein foods.

Not only they are laden with empty calories, they might make you crave real sugar and mess with your digestion. They can also have a negative impact on your energy levels.

Instead, use up your carbs on natural, vitamin-dense foods, like green leafy vegetables, bell peppers, broccoli, grass-fed red meat, oily fish.

See the list of best low-carb high-vitamin foods and  how to cook them all.

4. Find the right carbs level for you

To force your body into burning fat for fuel, you need to cut your carbs significantly.

On ketogenic diets, your carbs intake would be as low as 20-30g a day. Non-ketogenic plans are more liberal. But you still need to decrease your carbs substantially compared to what you normally consume.

Otherwise, your body will continue burning glucose. Your glucose levels will be low enough to make you feel tired and unwell, but not low enough to make the switch to fat-burning.

One way to surely derail your low-carb diet is to fall off the wagon every 2-3 days, have a high-carb meal, and then try to restart.

If this happens to you several times, then your chosen diet plan is not working for you.

You need to change your plan and go either higher, or lower, with your carb level. Either way can work well – as long as you can stick to it.

For example, if you keep failing because you find ketogenic diets too restrictive, try a more relaxed low-carb plan like Zone or South Beach.

If you are on a moderate low-carb plan, but not feeling great long-term, consider a ketogenic diet – if you can manage to get into ketosis, your weight loss will get much easier.

There is no one-size-fits-all solution when it comes to diet and nutrition. You need to find a plan that works for you individually.

See how to choose the right low-carb diet for you.

5. Track your food and check food macros

Getting the right amounts of “macros” – macronutrients: carbs, fat and protein – is crucial. If you don’t hit the right levels, your diet won’t be optimal and you may get side effects like tiredness.

Make sure that:

  • your carbs intake is low enough, and coming from high-quality natural foods
  • your fat intake is high enough
  • your protein intake is sufficient, and you get some protein with every meal

Don’t ever “guesstimate” the amount of carbs. Check all labels, and look up the values of natural foods.

In the beginning, you should definitely keep a food diary. If you don’t calculate your food intake precisely, you will err on the wrong side. That’s just how our brains are wired.

Check your chosen low-carb diet plan for guidelines on exact levels of carbs, fat and protein, or use this online calculator to calculate macros.

6. Move and exercise gently

When you are tired, the last thing you would feel like is moving. But you still need to do it. If you give in to your tiredness and just lie on the sofa, your body will conserve energy. There will be no imperative to switch to fat-burning.

The trick is to do something below your standard level of activity, so that it’s easy.

If you already exercise regularly, try doing your normal workouts, but at about 50-70% below par. For example, go for a 15-minute run instead of 30 minutes, halve your weights for strength workouts, etc.

The purpose is to do something that would expend energy, without over-tiring you. Once your body adjusts to low-carb nutrition, you can go back to your normal exercise levels, and more.

What if you are not a regular exerciser? Just go for a walk. Doesn’t matter how slow, or how short. Just do it. Drag yourself off the sofa and go. (And then definitely do consider regular exercise once you get past your metabolic switch.)

7. Take supplements

Nutritional supplements can make a huge difference during your low-carb transition period.

Some nutrients are known to reduce tiredness and improve energy-yielding metabolism. It’s the easiest way to improve your energy and help your body adjust to a low-carb diet.

Try one or more of the following supplements for more energy.

Energy supplements for ketogenic diets like Keto or Atkins Induction

Exogenous ketones elevate your ketone levels, creating an instant energy boost. The most common format is BHB salts – providing electrolytes and exogenous ketones in a single product. (Please note that “Raspberry Ketones” are NOT the same, despite the name – they are a bit of a scam that does precisely nothing for your ketosis.)

MCT oil (available as liquid, capsules or powder) converts to ketones quickly and creates a rapid energy boost.

Energy supplements for all types of low-carb diets

Co-Enzyme Q10 and L-Carnitine assist in creating of ATP molecule and help to transform fat to energy.

Key minerals – potassium and magnesium replenish your electrolyte levels. Electrolyte deficiencies can lead to Keto flu, which in turn leads to more tiredness.

High-quality multivitamins with extra-strong vitamins B and C> bridge potential nutritional gaps and improve energy-yielding metabolism.

Green tea extract provides a gentle energy boost plus several other weight-loss benefits like reduced sugar cravings and more effcient fat-burning.

You can buy low-carb supplements for tiredness from our online shop.

Don’t give in to fatigue – use these tips to fight it!

Low-Carb Diet Tiredness Fatigue

54 thoughts on “How to Fight Tiredness on Keto Diet”

  1. Pingback: Low Carb Diet Fatigue: Understanding and Overcoming Energy Slumps - Zeroing In On Health

  2. Pingback: Why am I so Tired on a Low Carb Diet? - Eat Little Beets

  3. I am on a fat fueled macrotype diet which calls for 99g Pro/85g fat/60g carb. I have been on it a week and a half. I find it difficult to meet that amt of fat. I am ending up about 10-20g too low on the fats and over by about 10-15 on protein. My carbs are usually slightly low or right on. I feel great, no cravings but definitely finding it hard to work out. Legs feel super heavy. Suggestions?

  4. I’m not sure what to do, have been feeling sensitive lately, leg soreness (tenderness by the ankle mostly) and sometimes feeling anxiety or high on coffee feeling and also constipated. I’m not overweight but have those few lbs I want to lose around my waist. I feel like keto is not working for me. I was having the head clearness in the beginning but don’t seem like it as much anymore. I workout 5x a week, 3 full body strength and two HiTT. I also do intermittent fasting as well. I skip breakfast and sometimes when I get close to my eating time i would not be hungry but my mind would feel funny and that is when I know I need to eat. I hear people don’t eat and how they can go on without. But I would feel a bit fatigue which I was never before when I wasn’t on keto. What am I doing wrong?? 9.5 weeks in keto. I should be adapted. I am in ketosis blood meter says 1.0-2.5. I really like the feeling I had in the beginning. Need some guidance. Also my calories are 1565 20-25 carbs, protein 92 and 121 fat. Most of the time I go over my calories. Hardly can stay under. Thanks in advance

  5. I’m so glad I found this information. So much of the info out there just says you’ll feel great and and the “flu” will eventually go away. But I had such an active lifestyle before the keto crash!!! Now I have to force myself to fold the laundry, force myself to the gym, force myself to cook dinner, etc! I feel like I gave up feeling fantastic, but always struggling to keep my weight down, to feeling exhausted, but my weight is no longer a struggle to maintain! It’s only been 2 weeks but definitely going to follow the advice here!! Supplements and frequent meals, just without the carbs 🙂

    1. Carbophobic (SITE AUTHOR)

      Hi MaryAnn, thank you, I hope you break through into ketosis soon! Keto flu is no fun 🙁

  6. I’ve been eating Keto for about a month now and I’ve lost 15 pounds which is great! But I’m torn about how I feel towards this diet because of how tired I am, I’m constantly craving something sweet and I’ve gotten very moody. Sometimes the slightest things get me agitated or I feel like crying all the time. Today I’ve been exhausted, I just woke up from a 2 1/2 hour nap and I’m still so tired. I had a friend who said she never got out of being sick on this diet and she ended up not being able to do it because she felt terrible for months. I really hope that doesn’t happen to me because the results so far are promising, but the way I’m feeling absolutely sucks!! If I still feel this bad after a month will it get any better? I should be in ketosis by now but I don’t feel like I’ve gotten my energy back or anything.

    1. Carbophobic (SITE AUTHOR)

      Hi Queshya
      Indeed, that does not sound good. You mention that you “should be” in ketosis – so I assume you are not 100% sure about this? I would start by measuring your ketones – the easiest way is to use Ketostix
      If you are not yet in ketosis, then your symptoms are not uncommon – the dreaded Keto flu. It usually goes away after a week or so – a month is quite a long time to be stuck there. I would guess (and I may be completely wrong, as I don’t know much about your situation) that perhaps your macros are not quite right – maybe not enough fat, or too much of carbs/protein. Have a look at this article – it covers all the reasons why this might be happening, and what you can do about it:
      Good luck!

  7. Ketoing one month, with supervision of a keto clinic. My goals are 6/20/70 I am a Diabetic with a A1c of 10. I have been hovering around a BG of 100, insulin shots has changed from 135 units a day to around 18 units . Drinking ACV and pink salt a gallon a day of water. I have lost 22 pounds but on so tired I took a 3 hour nap today… I just started MCT powder today by zhzou. Just so sleepy.

    1. Hi Laurie, great results! I hope you get fully keto-adapted soon and the tiredness will stop. MCT powder should hopefully help too. Best of luck!

    2. I’m a type 1 diabetic and have been on the ketogenic diet since January 2018, I have experienced similar results as I take a fraction amout of insulin then when I started keto and I’ve lost about 10 Lbs. I am experiencing chronic fatigue and just looking for a solution. My A1C was 7.2 when I started and is now 6.4 so I definitely don’t want to stop Keto as it has improved my blood sugar.

      1. Carbophobic (SITE AUTHOR)

        Hi Aaron, have you already discussed this issue with your doctor? If not, I would strongly recommend that as your first point of call. Another question is whether you are definitely in ketosis. Have you tried measuring your ketones levels?

    3. Drinking plenty of water is good. A gallon a day may be way too much and cause hyponatremia – dangerously low salt levels. I hope you told your keto clinic about this.

  8. Hi there!
    I’ve been on KETO since the new year. Have felt pretty good and have lost about 15 lbs. However, I seem to have plateaued weight-loss wise. Aside from adjusting my macros to slightly less calories and even slightly less carbs, I’m still not seeing the weight come off.
    Any thoughts? Thanks!

      1. What would you eat on Nil Carbs? I know eggs, meat, oils and butter, and bone broth have zero carbs and saurkraut is virtually nil but that doesn’t add up to much in the way of meals. Is there anything else you know of that can be added to this list?
        I’m 4 weeks into ketogenic diet and have been really strict, cooking only ketogenic meals from and following the measurements to remain under 20g of carbs a day but I’m so tired that I know I’m not keto adapted yet.
        If I go nil carbs with the foods listed above, how long will it take to get keto Adapted and if I go back to the under 20g a day meals I’m eating now afterwards will I remain keto adapted?

  9. I have been on the keto diet for 3 weeks now and actually feel very loved out but I have lost a significant amount of pounds 10 to be exact I eat under 20 carbs a day and I know the best is yet to come I just know that sometimes we have to get over the keto flu which does make a lot of sense so whoever is new to the keto diet hang in there be patient because I guarantee you the best really is yet to come

  10. Fernando Bancod

    I’m eating keto now for about 1 month. I’ve lost a few amount of weight. The problem is that after about 1 week in I started to feel more fatigued and tired. Most of the time, especially my legs feel so exhausted. Before, I would exercise a lot, and after a few hour exercise my legs would feel the same the next day. But this time even when I didn’t do any exercise I feel like this.
    When I do something demanding like walk the dog or bring the trash to the bin, or whatever I always feel very tired, it’s like I lost my edge performance wise. Even when I’m just sitting legs feel so heavy and tired and end up lying down the bed to rest. My whole body does but my legs the most.
    I had my blood glucose checked regularly and everything is perfectly okay. I used to inject insulin 4X a day. I have not used insulin except once when I accidentally ate fruits with sugar (banana) that spiked up my blood glucose.
    I need some advice so I can regain my energy and continue with the Keto diet.
    Thank you,

    1. Hi Fernando
      Have you tried all of the tips mentioned in this article, like supplementing electrolytes and double-checking all your macros (especially fat)?

    2. megan matichuk

      Hi Fernando, I’m a holistic nutritionist and to me, it sounds like you may be dealing with imbalance with your adrenals. A restrictive diet like keto may be causing some stress on your body that you aren’t prepared for (health-wise). It could be the fascia or the muscles causing the fatigue and/or pain.
      Do you have any food intolerances?
      Is your digestion up to par?
      What is the reason you’ve started keto?
      When I had adrenal fatigue years ago, one of the most prominent symptoms was the hurting legs – just always so exhausted and for a while, I couldn’t even walk half a block uphill. Eventually, as I healed my body, this pain went away, along with others. But I had to take it easy.. really easy. There needed to be zero stress in my life cause my adrenals were taking a break. Now my adrenals are quite healthy but I’m cautious not to overwork them. Trust your body and understand there is no shame in temporarily backing off of something to heal your body.
      Look up:
      Adrenal fatigue
      adrenal fatigue and keto diet
      You may be dealing with something different, but these are my thoughts.
      Shoot me an email if you have any other questions.

      1. Carbophobic (SITE AUTHOR)

        Thanks for your comments, Megan.
        I run this website and I really appreciate you contributing tips and advice. Thank you for properly introducing yourself and explaining your background.
        I have just one request – please be very cautious when talking about specific health conditions. As I am sure you are well aware, it would be impossible (and irresponsible) to diagnose someone over the internet, based on the very limited information people provide in comments. I would never do that myself so I would ask the same from you.
        I believe it’s ok to give generic tips about food or supplements, but mentioning specific health conditions is a different issue.
        You had pointed out at the end of your response that Fernando may be dealing with something different. Indeed – it could be just the natural Keto adaptation period, or electrolyte deficiency – or a hundred different possible reasons.
        So I welcome your contributions – but please let’s be careful and cautious when dispensing health advice.
        Thank you.

  11. hey. have started the keto diet at new year (yeah yeah lol) having no more than 40net carbs per day, and keeping my fat levels pretty good. (tracking and weighing) been 3 weeks nearly, the keto sticks say i’m in ketosis, but i feel like garbage! i’ve got this sickening fatty feeling in my stomach. my legs feel weak. i’m soooo tired all the time and even feel a little dizzy. i’m not doing this for weightloss, more to see if there are any performance advantages in my sport.. enduro mountainbiking. as the name suggests, it is endurance, to a degree. there are long periods of low output pedalling involved, but with 5-15min of very high intensity sprints, several times over the whole. not entirely sure i’ve chosen the right diet for this, as my recovery time after training is taking days at the moment.. any advice?

    1. Hi Daniel, this is a really interesting question. Here are my thoughts:
      1) Feeling rubbish – My best guess this is most likely to do with electrolytes balance, especially if you are already training hard. Keto depletes electrolytes anyway, and sweating during exercise depletes them even further. The symptoms you describe are consistent with electrolyte depletion – it is a common problem that strikes even those who are not athletes. Try supplementing electrolytes daily, plus some extra after exercise. The most important ones are magnesium, potassium and sodium (for sodium, you could just add extra salt to your food).
      2) Athletic performance in the short term – initially, most people experience a drop in their athletic performance. Your body needs time to adapt before it can use ketones for fuel as efficiently as glucose. It can take 4-6 weeks of ketosis to become fully Keto-adapted. After that, in theory, your performance should bounce back at least to pre-Keto levels.
      3) Athletic performance in the long term – once you are fully adapted and start to train while in ketosis, you may see an improvement in your endurance levels. There have been some related studies and success examples like Iron Man completed on Keto, that indicate there may be a positive effect. But to be honest, we are all different, so there is no guarantee that it will work out the same for you. You can only try and see – no one can predict precisely how it turns out for you.
      Overall, I would recommend sticking with the diet for another month or two (while supplementing minerals as above) – to become fully Keto-adapted – and then see how your training progresses after that.
      Bets of luck!

      1. How very timely, my finding this.
        I have been LCHF for 6 x weeks now whilst also intermittent fasting 15/9 – 16/8. My bodyweight hasn’t altered nor my body fat% as a triathlete i train 6 x days per week and was really hoping to find some extra energy here. Last weekend I totally bonked at the three mile mark in a 3.1 mile run. This is the second time this has happened, also in cycling i just dont have the strength any more.
        Running out of ideas so will try minerals as suggested

        1. It can take a bit of time to fully adapt. But hopefully, you are almost there after 6 weeks LCHF. Do try minerals supplementation – and best of luck!

  12. I have been at it for almost two years and I find that constant exposure to the mechanisms and science of high fat low carbs via YouTube and various podcasts really help keep me focused on my eating life style. My latest lipid panel was triglyceride-73,cholesterol-81,ldl 91. My doctor is completely dumbfounded! I’ve dropped about 45 lbs,[from 230 lbs down to 186. I’m 6′ tall] and I am almost never hungary. BTW had a stroke 5 years at age 59 so I’m really motivated.Don’t wait to have a stroke!

    1. What a fantastic result! Thank you for sharing it. I hope you will continue to stay and happy and healthy on your diet. Best of luck!

  13. I am just trying to lower my carb intake. I’m one of these idiots that have been able to eat whatever I want throughout my life, not gain and pound and never get sick. I’m 57 now, and feeling the effects of my terrible eating habits and know I need to change something. I don’t want to go in to ketosis or cut carbs out completely. I’m just setting myself up for failure. But for the last 9 days, I haven’t eaten any bread, pasta, rice, no pop tarts, peanut butter filled crackers, potato chips, candy bars, candy, stuff that I was eating daily 10 days ago. I’m eating a lot of protein, meat, nuts, etc., some fruit, cole slaw like there’s no tomorrow, taking vitamins, probiotics, cinnamon, red yeast rice, calcium with magnesium, a B-12. I make sure I go outside and work in the yard and sweat (in South Louisiana, this only takes about one minute outdoors). After explaining all this, Day 9, I’m so exhausted I can barely function. I feel like I’m drunk, like I’m in a haze. I guess I would have hoped that I would be feeling even a little better. I expected to feel bad for a few days cutting down (not out) the extreme amount of sugars and carbs. The reason I started this whole thing was because I was feeling so out of it. I guess I just need more time?

    1. Hi Kris,
      First of all, well done on deciding to change your eating habits. All doctors agree that cutting out sugar and junk food is the right thing to do.
      You say that you don’t want to go into ketosis, but just trying to cut down on carbs. This makes it a bit more tricky, as ketosis does improve your energy once you break through to it.
      I think the key in your situation is to figure out exactly how much you should get of each macronutrient – carbs, protein and fat. Any carbs that you cut out should be replaced mostly with fat – you need either one or the other for energy.
      Start by using a macro calculator (like this one: to figure out how many calories you need, and how best to split them between carbs/fat/protein.
      If you don’t want to go into ketosis, set your carbs level anywhere between 60-100g a day, and use the form to determine the optimal amounts of fat and protein.
      You will then need to track your food for several weeks to make sure you are hitting your targets across all macros. Use a tracking app or a diary, and weigh your food. If you never had to watch your food in the past, you might find that your estimates are well off.
      This may seem tedious but it is important if you are serious about changing your eating habits completely. With such a major change to your lifestyle, your habits will try to hold you back – so tracking is crucial.
      I would also recommend cutting out fruit and nuts during this transition period. Fruit is quite high in sugar and can spike your blood glucose just like candy.
      If you balance out your carbs/fat intake, your energy levels should improve. Your body will also gradually get more used to running on fat.
      Best of luck – and shout if you have any further questions!

        1. Yes, absolutely. This is mentioned already in the supplements section. But you are absolutely right – this point is really important, so I will expand it to include more information. Thank you for pointing it out!

    2. megan matichuk

      Give your body time. It is only adjusting – whether you’r moving towards a keto diet or not. You’re doing a fantastic job at cutting out the super high refined sugars.. and especially if you’ve been eating them for 50+ years, your body is going to go into shock. This is why you feel like shit. One incredible thing about the human body is that it is restorative and you are giving it plenty of what it needs, fresh foods like coleslaw, nuts and fruit; supplementation: probiotics, calcium, magnesium (consider getting a B Complex instead of just B12 – all the B vitamins work better together) so in time, your body will adjust and you’ll start feeling like a superhero.
      My thoughts.
      Don’t take on too much at once, and be patient. You will be rewarded.
      megan, holistic nutritionist.

  14. Somehow, I dont loose weight right now – I am doing keto. I wondering why. Maybe the adaption time takes some time (before two weeks one day cheat day?!). What could it be? I have also some fatigue, but it is getting better. I have enought protein and I think I have enought fat. My carbs I guess are maybe at 20- 30g.

    1. Hi Ben,
      If you are having any problems on Keto – such as slow adaptation or weight-loss plateau – the best thing to do is to start tracking your food and macros precisely, rather than guessing it.
      Many scientific studies show that humans vastly underestimate the amount of calories (and carbs) consumed – unless you specifically track and record everything. Many are shocked by the results when they first start tracking – it could be well off from your estimates.
      So I would definitely suggest precise food tracking as the first step.
      Best of luck!

  15. Hi,
    I’m day 1 into my keto diet and already feeling fatigued and low on energy. I believe this may be an issue related to insufficient caloric intake. How can I increase the amount of calories to a suffient enough level whilst maintaining active ketosis?

    1. Hi Jordan,
      It’s highly unlikely that you are already in ketosis after just 1 day of Keto. It can take several days, or even weeks, to switch to ketosis. Feeling fatigued at this stage is normal.
      Calories are actually not that important at this stage. Your macronutrients breakdown is the crucial part – making sure your carbs are low enough, and that you are also getting plenty of fat. Other points mentioned in this article may also help – like electrolytes supplementation.
      Generally, it is perfectly normal to go through at least few days of fatigue when you are first starting on Keto. Give your body some time to adjust!
      Best of luck, and I hope you will feel much better soon.

  16. How can you suggest vegetable oils? I have read nothing good about them and avoid them like the plague.

    1. Hi Heidi
      I agree that some vegetable oils are quite nasty. But it really depends on the type and the processing method. For example, coconut oil, avocado oil, flax oil and cold-pressed olive oil are all good choices. Obviously, I don’t recommend cheap industrial processed versions like sunflower or rapeseed oil.
      Thank you for pointing this out though. I expanded the point about vegetable oils to make this distinction more clear.

    1. Thanks for pointing it out Shai. Indeed, that point was not worded well. I have edited it now. Thanks!

  17. Pingback: 8 Ways to Blast through Low-Carb Flu and Dive into Ketosis – Low Carb Diet Support

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