When you don’t get enough electrolytes on Keto, your health notices. We’re talking about low energy, muscle cramps, brain fog, headaches, weakness, insomnia, and several other symptoms of the infamous Keto flu.
The Keto flu often gets pinned on a bumpy transition to fat-burning, and that’s not always wrong. But in many cases, the Keto flu is a case of low electrolytes.[*]
The minerals called electrolytes are important for everyone, but they’re especially important for Keto folks. Why? Because low-carb dieters have multiple forces pushing them towards deficiencies.
We’ll review those forces in a moment. (And how to fight them). First, though, let’s cover some basics.
What Are Electrolytes?
An electrolyte is a mineral that can conduct electrical charges in your body. These charges are how nerve cells communicate—allowing us to think, move, and beat our hearts.
Electrolytes also regulate water distribution inside and outside your cells. This function, called fluid balance, is synonymous with healthy hydration. Proper fluid balance keeps your skin moist and supple, your blood flowing smoothly through your veins, and your brain suspended in cerebrospinal fluid.[*]
The electrolytes gang includes sodium, chloride, potassium, magnesium, calcium, phosphorus, and bicarbonate. We’ll talk soon about which electrolytes matter most.
Electrolytes enter your body through diet and leave through urine, sweat, and feces. All the while your kidneys—and a slew of hormones like insulin, aldosterone, renin, angiotensin, and antidiuretic hormone—work hard to maintain healthy electrolyte levels in your body.[*]
This system typically works great. But over time, if you don’t consistently replace lost electrolytes, you can end up with a nutritional deficiency.
This happens a lot on Keto. Let’s see why.
Electrolytes on Keto: Why You Need More
If you’re eating a low-carb diet, you probably need more electrolytes than the average person. There are two main reasons for this:
- A clean, whole-food Keto diet tends to be lower in certain electrolytes.
- When you restrict carbs on Keto, you lose more sodium and potassium through urine.[*]
Let’s take these one at a time.
First, whole foods contain scant sodium. (No salty packaged foods either). The burden falls on you to get enough sodium from the salt shaker.
Potassium can be tough too. Many potassium-rich foods—fruits, potatoes, starchy root vegetables—have too many carbs to be Ketogenic.
Magnesium and calcium? Doable on Keto, if you’re eating green leafies, cruciferous vegetables, and dairy. If not, you might be deficient.
Force number two is increased electrolyte loss on Keto. Some explanation will help.
When you restrict carbs on Keto, the hormone insulin stays low. Low insulin then signals your kidneys to activate “diuretic mode”, and you start losing more water, sodium, and potassium through urine.[*]
Most people replace the water. The world is full of over-enthusiastic hydration advice.[*]
But if you get too aggressive with fluid replacement, you make the electrolyte problem worse. You dilute blood sodium levels, which can result in brain fog, headaches, and cramps. Sounds familiar, doesn’t it?
Electrolytes and Keto Flu
Electrolyte deficiencies are an under-appreciated cause of Keto flu. This low-carb malaise usually gets blamed on dehydration, low blood sugar, or the transition to using ketones for brain fuel.
These are all potential reasons. But if the symptoms persist beyond a few days of Keto dieting, it’s probably an electrolyte issue.
If you look up the consequences of sodium deficiency, potassium deficiency, magnesium deficiency, and calcium deficiency—you see a lot of familiar symptoms. Headache. Fatigue. Weakness. Dizziness. Brain fog. Muscle cramps. Insomnia. All stuff you don’t want.
Once you address the deficiency, the symptoms should dissipate. But before you do that you need to do some tracking.
Some electrolytes are more important to track than others. Almost nobody is deficient in phosphorus (most people probably get too much)[*], and your body can synthesize bicarbonate. And since sodium and chloride come together as salt, you only need to track sodium.
This leaves four: sodium, potassium, magnesium, and calcium. Let’s briefly review them.
Sodium is the main electrolyte found in extracellular fluid (the fluid outside your cells).[*] It’s needed to maintain blood volume so blood can reach the right places, like your brain.
Low sodium is probably the most common deficiency for low-carb dieters. You lose it through sweat, you lose it through urine, and you only get it from the salt shaker and certain foods, primarily those that have been packaged and prepared (and thus not ideal to optimize nutrition). Bumping up sodium will likely fix many cases of Keto flu.[*]
- Difficulty concentrating
- Nausea & vomiting
- Muscle cramps
- Brain fog
Found in meat, fruit, and vegetables, potassium is your intracellular fluid balancing mineral. Higher potassium intakes have been linked to lower blood pressure in a variety of populations.[*]
Symptoms of a deficiency may include [*]:
- Muscle cramps
- Muscle twitching
- Heart palpitations
Potassium target. The suggested intake is at least 3.4 grams of potassium per day for men and 2.6 grams for non-pregnant women (the evidence-based RDA) from diet and supplements. The National Academies of Science, Engineering, and Medicine has recommended daily consumption of 4.7 grams since doses at this level appears to lower blood pressure in those with high blood pressure and decrease risk of kidney stones.[*] Higher potassium intake is associated with lower risk of stroke.[*][*] Luckily, a variety of Keto-friendly foods are rich in potassium, including avocado, fish, beef, eggplant, and leafy greens.
Magnesium usually doesn’t function as an electricity-conducting electrolyte, but it wears hundreds of other hats in the human body. For instance, magnesium supports nearly 300 enzymatic reactions, including reactions involved in DNA replication and repair and the production of the cellular energy currency, ATP.[*]
- Muscle cramps (particularly in the legs)
Magnesium target. The RDA for magnesium is 420 mg per day for men and 320 mg for women, but anthropological evidence suggests our ancestors consumed 600 mg per day.[*] Anywhere in that range should do. Keto-friendly dietary sources include dark chocolate, avocado, low-carb nuts, fish, and leafy greens.
If you’re looking for calcium in your body, you’ll find 99% of it in your skeleton[*] Getting enough calcium is not only crucial for building bone, but also for regulating muscle contraction, nerve impulses, and the actions of various hormones.
Symptoms of a deficiency may include[*]:
- Muscle cramps
- Muscle twitching
- Sensations of pins and needles
Calcium target. Shoot for 1 gram per day (the RDA) from calcium-rich foods like dairy, bones, and cruciferous vegetables. Consider avoiding supplements, unless suggested by your healthcare provider, as supplemental calcium may adversely affect heart health.[*]
How To Get Enough Electrolytes on Keto
To determine your electrolyte status, start with a full dietary assessment. Log all your meals in the Carb Manager app, and take note of sodium, potassium, magnesium, and calcium intakes. These are automatically calculated for you.
If you’re short of your targets, you have two options:
- Eat more electrolyte-rich foods
Lean towards door number one whenever possible. If you do decide to supplement, take smaller amounts with meals to mimic how electrolytes are naturally consumed.
Yes, optimizing Keto electrolytes requires some up-front planning. But once you put in the work, your system will practically run itself. Then you can stop thinking about electrolytes and start thinking about puppies, flowers, and rainbows.