It’s a common misconception for those new to the ketogenic diet to expect an immediate physical and mental boost, but such is rarely the case.

For many (in reality, for most), switching to a strict low-carb diet like keto will leave your body experience a wide range of adverse symptoms. This is referred to as the “keto flu”, and happens typically within the first few weeks of a low-carb diet when your body begins flushing sodium and water out of the body.

This can leave you feeling tired, nauseous, and irritable, but fear not. Like most things in life, this too shall pass, and typically within a couple of weeks.

Another troubling side effect of a low-carb diet is dehydration and electrolyte imbalances. Luckily, since you’re reading this article, you’ll learn how to handle these bodily changes and deficiencies quickly and efficiently.

Dehydration and Fluid Loss

Sometimes referred to as the elixir of life, water makes up roughly 60% of our body weight and is what every cell, organ, and tissue in our body depends upon to function properly.

Research has shown that many people simply do not drink enough water.[1]

Every day, water is excreted through breath, sweat, urination, and bowel movements, and it carries essential nutrients to our body’s cells.

When we consume carbohydrates, our body converts the excess to glycogen, which is stored in our muscles and liver and saved for energy. For each gram of glycogen that is stored, we gain anywhere from 2.7 to 4 grams of water.[2] When the body stores more water, the kidneys retain more sodium, which can lead to the bloating effects of high-carb meals.

By drastically restricting carbohydrates, the body rapidly sheds water weight. This is why dehydration is the most common side effect of a ketogenic diet during the first few weeks.

Dehydration can beget its own slew of unpleasant side effects, primarily constipation. This is one of the biggest challenges people on the keto diet face. Being constipated can significantly reduce the quality of life and throw you off your keto regimen.

While on the keto diet, constipation can also result from an electrolyte deficiency (especially potassium, sodium, calcium, and magnesium), and not consuming enough fibrous vegetables and fermented foods and drinks.

How to Remedy Dehydration

While on a ketogenic diet, your body will absolutely require a much higher intake of water, so drink up! This holds especially true in the first few weeks of the diet when your body is still adapting to the change.

While the amount of water consumption needed daily depends on a variety of factors, the general rule is to drink about one ounce of water per every kilogram you weigh, daily.[3] For example, if you weigh 90 kg, aim for about 90 oz of water per day, minimum (and be sure to take a sip at least every 45-60 minutes throughout the day).

Electrolyte Imbalances

What are electrolytes?

Electrolytes are essential minerals present in your body that gain electrical charges when mixed in solutions. In turn, they can conduct electrical current throughout the body. This is an important characteristic that enables many cellular processes to occur. Hence, electrolytes are necessary for the overall functioning of your muscles, heart, brain, and virtually every other organ.

How electrolytes are affected by keto

Electrolytes are found in your blood, bodily tissues, urine, stools, and more. On a low-carb diet, lots of electrolytes are excreted through urine and bowel movements and need to be replenished. This imbalance of electrolytes can often result in fatigue, dizziness, headaches, and even muscle cramping—all symptoms of the keto flu.

Just like the issue of dehydration, electrolyte imbalance is a fairly easy one to remedy.

The four primary electrolytes to keep an eye on and replenish are potassium, sodium, magnesium, and calcium.

4 Primary Electrolytes

1. Potassium

This is the electrolyte most often lacking in the keto diet since it’s found in foods that are typically higher in sugar and starchy carbs. There are some foods, however, that are both low in carbs and high in potassium, including salmon, avocado, and dark leafy greens. Beware, a severe deficiency in potassium (hypokalemia) can increase the risk of type-2 diabetes.[4]

2. Sodium

Being in a state of metabolic ketosis leads to sodium being flushed out of your body quicker. This occurs because when your insulin levels decrease, the speed at which your kidneys extract sodium also decreases.[5]

This can easily be fixed by adding more salt (preferably pink sea salt) to your meals and consuming more bone broth. It’s important to know as much as possible about ketosis before you enter this stage to ensure the process is done so safely.

While high sodium intake typically is the result of a high-calorie and high-carb diet (which can result in hypertension and obesity), individuals on a low-carb diet actually need that extra sodium.[6]

3. Magnesium

Magnesium deficiency (hypomagnesia) is becoming quite prevalent among the general population, and this electrolyte deficiency can have significant health ramifications if left untreated.[7]

If you’re experiencing symptoms of hypomagnesia, like dizziness, constipation, and muscle cramps, you may need to support your diet with magnesium-rich and keto-friendly foods like dark chocolate, avocado, mackerel, almonds, and brazil nuts.

4. Calcium

A recent scientific report based on food supply and composition estimates roughly 7 out of every 10 adults in the U.S. are deficient in calcium (hypocalcemia).[8] When most people think of calcium, they immediately associate it with bones (rightly so).

Skeletal bones house more calcium than any other tissue in the human body (around 99% of all calcium in the body is deposited in bones). For this reason, the amount of calcium in the blood is maintained in a very tightly regulated range.

The intercellular matrix (i.e. space between cells) of bone tissue contains an abundance of calcium salts, particularly calcium phosphates. When blood calcium levels drop below normal, calcium is released from bone matrix so that there will be an adequate supply for metabolic needs.

Over time, this increases the risk of frail bones, fractures, and osteoporosis.[9] Naturally, getting enough dietary calcium every day is increasingly important as we age.

Be sure to check out: 10 Calcium-Rich Foods to Eat on Keto

Should you choose to supplement with calcium, be sure to use dicalcium phosphate and/or chelated calcium for maximal uptake and absorption.

Using an Electrolyte Drink for Keto

Apart from consuming electrolyte drinks for staying hydrated during sports, it’s also a very effective keto-flu remedy. It will help boost the electrolytes your body is severely lacking on a low-carb keto diet.

There are plenty of electrolyte drinks out there on the market, or you can even try making your own using one of the many online recipes out there.

Another option is to use KETO BHB, which provides nearly about 20% of the recommended daily intake (RDI) of calcium and sodium and 41% of the RDI of potassium (per serving).

While there are simply tons of resources, research, and studies available regarding the ketogenic diet, it can be difficult to consume it all.

If you have successfully made it through this article, you are now one step ahead when it comes to safely using the keto diet. You’ve been equipped with the know-how in avoiding its nastier side effects, like the keto flu.

In summary, due to the natural loss of water and electrolytes, do your best to stay hydrated and get the potassium, sodium, calcium, and magnesium your body needs to continue functioning at its best.


[1] Gandy, J. (2015). Water intake: validity of population assessment and recommendations. European journal of nutrition54(2), 11-16.

[2] Fernández-Elías, V. E., Ortega, J. F., Nelson, R. K., & Mora-Rodriguez, R. (2015). Relationship between muscle water and glycogen recovery after prolonged exercise in the heat in humans. European journal of applied physiology115(9), 1919-1926.

[3] Drewnowski, A. (2015). Evidence behind daily water and beverage intake recommendations. Nutrición Hospitalaria32(2), 17.

[4] Chatterjee, R., Yeh, H. C., Edelman, D., & Brancati, F. (2011). Potassium and risk of type 2 diabetes. Expert review of endocrinology & metabolism, 6(5), 665-672.

[5] DeFronzo, R. A. (1981). The effect of insulin on renal sodium metabolism. Diabetologia21(3), 165-171.

[6] Song, H. J., Cho, Y. G., & Lee, H. J. (2013). Dietary sodium intake and prevalence of overweight in adults. Metabolism, 62(5), 703-708.

[7] Al-Ghamdi, S. M., Cameron, E. C., & Sutton, R. A. (1994). Magnesium deficiency: pathophysiologic and clinical overview. American Journal of Kidney Diseases24(5), 737-752.

[8] Kumssa, D. B., Joy, E. J., Ander, E. L., Watts, M. J., Young, S. D., Walker, S., & Broadley, M. R. (2015). Dietary calcium and zinc deficiency risks are decreasing but remain prevalent. Scientific reports, 5, 10974.

[9] Heaney, R. P. (2000). Calcium, dairy products and osteoporosis. Journal of the American College of Nutrition19(sup2), 83S-99S.