Maximize your nutrients, minize your calories

The Lowest Calorie Electrolytes For Fasting

Are you fasting right now? planning on one? Perhaps a water only fast, or maybe just a 500 calorie a day fast. The list of different fasts is endless.

But, what they all have in common is that they limit caloric intake, either directly or indirectly.

But, while minimizing your calories you still want to get as many nutrients and electrolytes as you can.

So, let's take a look at 6 main electrolytes and see how you can get the most from each of them without increasing your calorie intake by much.

Sodium and Chloride

This one's super easy. If you're not already getting more than enough sodium from your diet, you can always just add a bit of table salt to your drink or food. Table salt is mostly 50% Sodium and 50% chloride.


This is a big one. It's tough to reach 100% of your RDI (recommended daily intake) for potassium on a low calorie diet. It's even harder when your fasting - not that you need to reach 100% while fasting.

Not getting enough potassium in your body can lead to muscle cramps in your arms or legs. You can get high blood pressure or constipation. And, if your constantly craving sugar and sweetness then you might have a potassium deficiency. That's because, back in the day, when humans were evolving, we got a lot of our potassium from fruits which are high in potassium. And, since fruits are sweet, sugar cravings were a signal to our brain to eat more fruits which contains more potassium.

But, getting enough potassium without all the sugar, while on a fast is a bit tricky. Here's a list of super easy high potassium snacks. And, dont' forget about coconut water, it's loaded with potassium!

But, if you're on water only fast, the above simply won't do. So, I'll introduce you to my secret weapon: Creme of Tartar!

Creme of tartar is actually a baking good you can find in any grocery store. It's usually added to baked goods in small quantities to help it get foamy. Creme of tartar comes from the residue of fermintation of grapes.

All you have to do is add a little creme of tartar to your water, about 1 tsp, is plenty. It's almost 0 calories and 1 tsp has roughly 13% of your daily intake for potassium or roughly 1 bananas worth of potassium.


This is another difficult one because it's not generally found in super high quantities in many foods. But, your best natural bet is Greens. Greens have by far the highest density of Magnesium. The 5 highest foods are the following:

As usual, all data is normalized to 200 calories. A single leaf of Swiss Chard has 9% of the daily recommended Magnesium for just 7 calories: which won't break your fast. Wow! That is impressive.

Item Magnesium
Swiss Chard 244%
Purslane 243%
Spinach 196%
Beet Greens 182%
Wheat Bran 162%
*All our data comes from the USDA Nutrient Database.

Now, the wheat bran you can get at a grocery store and then put it in your oatmeal for added Magnesium. Just keep in mind, it does reduce the absorption of vitamins a bit, so don't relly on it too much.


Calcium is very easy to get in large quantities from just about anything in the dairy section of the supermarket. Even vegan options like soymilk and almond milk are loaded with calcium because the manufacturer adds calcium sulfate to it. Milk of course is famous for it's high calcium content but the body doesn't even absorb most of it: much of it gets urinated out.

But, I wouldn't recommend relying on just 1 source for any kind of nutrient. So, let's look where-else you can get your calcium. As you can see below, watercress is particularly impressive due to it's extremely low calorie content which pumps up it's 200 calorie normalized percent. A small handful of that, 1 cup would be about (40mg) 8% of your DRI (500mg according to WHO).

Normalized to 200 calories:

Item Calcium
Watercress 436%
Pak-Choi 323%
Arugula 256%
Beet Greens 213%
Collards 193%
Spinach 172%
*All our data comes from the USDA Nutrient Database.

Generally speaking, green vegetables are loaded with calcium and you can get that from a variety of veggies or other sources, as shown in our Nutrient ranker


This one doesn't get much press time but it's no less important. here are some of the top winners for Phosphorous:

Normalized to 200 calories:

Item Phosphorous
Watercress 188%
Portobello mushrooms 172%
Wheat Bran 162%
Zuchinni 153%
Yeast 151%
White mushrooms 135%
*All our data comes from the USDA Nutrient Database.

Other Sources

I'm sure you've heard so many drinks advertised everywhere, like Gatorade, etc. The labels often claim they contain electrolytes. but, actually they're loaded with sugar and only contain 1 kind of electrolyte: Sodium.

Now, don't get me wrong, sodium is very important, especially if you're excercising on a hot day. In fact, you'll typically sweat out sodium a lot faster than potassium in a hard workout. But, typically they don't contain any other electrolytes.

Water Fasting

With water fasting, you aim to take in as close to 0 calories as possible. So that really limits our options. But here some of the best:

Item Benefits
Coffee Potassium, Magnesium
Creme of tartar Very high in potassium
Mineral Water Drink something fun with 0 calories

With coffee, we're talking about just coffee, nothing added in. It's pretty darn good, for nearly 0 calories you can get about 2-4% of your DRI for potassium and magnesium.

How much?

Your body works really hard to keep the supply of electrolytes in your body stable, balancing it by adjusting the amount that gets released through urine and sweat. You can actually suffer severe side effects if you get way too much or way too little of any of these important electrolytes.

You could even die. In fact, that's how they used to execute people on death row. They would inject them with Potassium chloride thus creating a electrolyte im-balance that the body couldn't recover from.

So, don't overdo it and don't underdo it. Don't worry too much. Your body was made to handle quite a bit of variation in electrolyte intake.




Kale.World is all about nutritional density – all our findings are normalized on a per calorie basis, making it easier to compare various foods.