7 Reasons Why You Are Tired on Keto

author avatar Dr. Eric Berg 08/31/2023

Let me guess…

You dove into the keto diet awhile back after you saw the results some of your friends were getting a few weeks after ditching carbs and eating lots of healthy fat on the ketogenic lifestyle:

Weight loss as fast as the snow melts on the first warm spring day. Mental clarity like they’d gone back years in time. Gloating about how much more energy they have now that they're in ketosis.

You’re happy for them.


Oh, sure, you made it through that rough first week when you had such bad breath you could stop a Mack truck, and you felt like something the cat dragged in because of keto flu symptoms.

Now you’re seeing results.

You’re sure you’re fat-adapted. Your weight loss is impressive. You’ve taken in your belt a few notches. Soon you’ll have to invest in new clothes in a smaller size.

All good.

But one thing makes you grind your teeth and shoots up your blood pressure: that high energy your friends rave about has totally eluded you.

In fact, you feel tired on keto. Even though you've successfully reduced your carbs until you're in ketosis. You've been expecting that big burst of energy. But...it hasn't come.

What gives?

One of the benefits you really wanted was more energy. You've got a busy life. Burning ketones was supposed to rev you up.

You wonder, “Was going keto a mistake?”.

Not at all.

There are seven easily remedied reasons why you could feel lethargic on keto even after you ditched your high-carb way of eating.

Ready to find out what they are?

Let’s go.

#1 Your B Vitamins Could Be Low

If you’re deficient in B vitamins, you’ll feel tired. B1 and B5 are especially crucial for helping to regulate your metabolism and make energy; thus, you want to make sure you’re consuming adequate amounts.

I recommend getting your B vitamins from nutritional yeast. You can get it in either powder or tablet form. Make sure whichever one you choose isn’t fortified, because fortification is synthetic - meaning it’s made from petroleum. Nutritional yeast has a pleasant, cheese-like flavor. If you like the powder, sprinkle it over steamed vegetables or add it to your smoothies.

If you're tempted to buy vitamins, I suggest you don't. The only time I recommend synthetic forms of B vitamins is for a short-term need such as when you’re doing some kind of detoxification and want the temporary infusion of higher amounts of vitamins. But in the long-term, you’re better off using a quality food source such as nutritional yeast to boost your B vitamins.

#2 You Have A Potassium Deficiency

Potassium is one of the minerals vital to your overall health and is an important electrolyte. Potassium deficiency is staggeringly common in our society yet most people aren’t aware they’re deficient because it’s difficult to detect by a routine blood test.

If you’re on the standard low-carb ketogenic diet, are in the fat-burning state of ketosis, and are feeling fatigued, that's a symptom of potassium deficiency.

But my Healthy KetosisTM diet emphasizes eating a significant amount of high-quality vegetables because eating them - for example, in a large salad containing 7-10 cups - is the best way to remedy fatigue from potassium deficiency.

If you simply can’t abide by large amounts of salad vegetables a couple of times a day, there are a few excellent options to increase your potassium intake:

  • Use electrolyte powder

  • Consume a concentrated green powder such as raw wheatgrass juice powder

  • Make a vegetable shake and drink your salad

  • Steam or saute vegetables and add healthy fat such as butter or olive oil to them

#3 You Have A Stomach Acid Deficiency

Stomach acid deficiency is another very common condition. Your stomach acid is probably one of the most important fluids in the entire body because the cascade of negative effects that you will experience without enough of this important acid is cataclysmic. A lack of enough acid in the stomach can affect your ability to:

  • absorb vitamins,

  • prevent acid reflux (GERD); and,

  • break down proteins that create essential hormones like serotonin, which contributes to your happiness and well-being.

As well, without enough stomach acid, the food sits there without properly digesting, causing you to feel tired.

One excellent way to boost your stomach acid is to consume apple cider vinegar either as a liquid or tablets. And there are several more ways to encourage your body to make more hydrochloric acid in your stomach:

  • Increase your potassium by eating more green vegetables

  • Use sea salt

  • Consume betaine hydrochloride, found in spinach, beef, and shrimp (all excellent foods for a keto diet)

Though stomach acid isn’t the sexiest subject, it’s worth your while to correct a possible deficiency.

a drawing of a man’s torso with colors indicating heartburn

#4 You’re Consuming Hidden Carbs

You may be eating food that has hidden carbs; ones that you simply don’t consider because they’re an ingrained part of your everyday eating scenery. The common ones people overlook are:

  • Grains

  • Starches

  • Fruits

  • Legumes (beans)

Other sources of hidden carbs are even sneakier. They include sweeteners such as:

  • Splenda

  • Honey

  • Molasses

  • Agave

And common seasonings have a surprising number of net carbs, including:

  • Garlic powder

  • Chili powder

  • Paprika

If you’re on the keto diet, it pays to scrupulously examine what you may still be eating - like fruit - or adding to your food, or cooking with. You could be unintentionally consuming a much higher number of net carbs than you realize. Those hidden carbs will cause your blood sugar to spike and your pancreas to release a flood of Fat Storing Hormone to bring down the glucose, making you feel tired.

#5 Your Blood Sugar Is Too Low

Low blood sugar is called hypoglycemia. This condition happens when there’s too much Fat Storing Hormone in your bloodstream in response to too much blood glucose. Fat Storing Hormone floods in, trying to bring your blood sugar back into the normal range of 80-100 mg/dL. It’s your body’s way of trying to normalize your body chemistry, but too much Fat Storing Hormone will drive down your blood sugar like a hammer pounding a nail.

And what causes high blood sugar? Eating too many carbohydrates! (Now you see why it’s important to find and get rid of hidden carbs - as I described in #4 above - even after you’ve initially lowered your intake of more obvious carbs on keto.)

If you get instant energy when you eat, you can tell this is a low blood sugar issue causing your fatigue. And if you’ve been fasting while still eating a fairly high carbohydrate diet, or consuming hidden carbs, you’ll definitely feel tired as one of the side effects of hypoglycemia.

But if you combine my Healthy KetosisTM way of eating with intermittent fasting, you can correct hypoglycemia over time.

Two hands holding up a sign that says Blood Sugar

#6 Your Blood Sugar Is Too High

I just finished telling you that your blood sugar might be too low, and now I’m saying it could be too high. What!

But here’s how this could happen:

For years. you probably had several times the normal amount of Fat Storing Hormone in your body, in response to eating a lot of carbohydrates and sugar. All of that Fat Storing Hormone was required to keep your blood sugar pushed down into a normal range.

Then, you go keto. With its high fat, moderate protein, low carb profile, keto is designed to keep your Fat Storing Hormone levels low. Especially if you’re fasting too.

Without its customary load of Fat Storing Hormone to keep your glucose levels normal, your blood sugar levels will rise. Don’t worry; this is temporary as you transition more deeply into keto.

You can tell if your blood glucose is too high if you’re tired after you eat. As with blood glucose that’s too low, the combination of Healthy KetosisTM and intermittent fasting will correct your high blood sugar issue over time.

#7 You Aren’t Getting Enough Sleep

Stress is the number one reason people develop sleep problems and unfortunately counting sheep does not work for getting to sleep.

You’re stressed. You’ve got a thousand things on your mind. Your thoughts leap around like a troop of crazed monkeys taunting your wakefulness.

You toss. You turn. You stare at the clock as the minutes crawl by.

In response to poor sleep, your body ups its levels of stress hormones. If you were able to get a period of a deep sleep, your body would get the message to shut off the stress hormones. But you can’t get deep sleep because...you’re stressed!

Oh, and Mother Nature doesn’t stop there - stress hormones peak in the afternoon and evening just when you ought to be winding down to prepare for sleep.

It’s a vicious circle. But you can break it.

I’ve got one unique tip for you that will help you improve the quality of your sleep: enhance the air quality and increase the amount of oxygen in your bedroom by adding specific plants.

And here are five more helpful tips to help you fall asleep quickly and stay asleep:

  1. Always sleep on your right side

  2. Slow down your breathing

  3. Go to bed no later than 10:30 pm

  4. Regulate your pulse rate

  5. Use a massage tool

These tips will help you get into the deep sleep stage known as delta wave sleep. Because a keto diet can cause delta wave increases, you give yourself an advantage when you stay with the keto way of eating.

Another simple remedy is an obvious one that people sometimes forget: take a nap!

The Truth About Being Tired On Keto

Changing up your way of eating from high-carb, low-fat to keto is hard. There’s no doubt about that.

You stuck with it through those first awful days of the keto flu when your head was pounding and your body ached as though you’d been hit by a train.

You moved through a few intense carb cravings when you would have killed for a cookie.

Just one cookie.

What could it hurt?

But you persevered. You kept your commitment to yourself and left the goodies uneaten.

Just when you’re patting yourself on the back for your progress…

You realize you’re ridiculously tired. That infamous keto energy eludes you. When your friends exclaim about their unbelievable energy levels, you want to plug your ears and shout “La la la la, I can’t hear you!”

Don’t become a tortured keto adherent.

Choose to discover which of these seven reasons could be causing your fatigue. Use the remedies.

Experiment. Find out which ones work for you.

Because there’s no reason to plug along on keto feeling tired.

Come on. Your high energy is waiting for you.

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Healthy Keto Guide for Beginner

FREE Keto Diet Plan