This article covers electrolyte supplementation during water fasting. It does not apply to dry fasting.
If you are on any medications, have any medical conditions or health concerns, are pregnant or lactating – please consult your doctor before fasting and before taking any supplements.
Fasting Electrolytes Questions and Answers
- Why do we need to supplement electrolytes while fasting?
- Do all types of fasting require electrolyte support?
- Will electrolytes break my fast?
- What are the key electrolytes to supplement?
- How much electrolytes do I need during fasting?
- How to find my personal optimal level of fasting electrolytes?
- What are the symptoms of electrolyte deficiency during fasting?
- What’s the safest way to take electrolytes?
- How did people cope with fasting in the past without any supplements?
- When is the best time of the day to take electrolytes?
Why do we need to supplement electrolytes while fasting?
Electrolytes are electrically charged minerals that are essential for the normal functioning of almost all of your body’s systems and organs. Normally we get a steady supply of them with food and drink.
During fasting, you are no longer getting your electrolytes from food. Your body has a small reserve of electrolytes stored in its tissues. But they deplete quickly, usually within the first 24-48 hours.
As soon as your body runs out of electrolytes, you will start feeling the symptoms of electrolyte deficiency. The most common ones are headaches, fatigue, irregular heartbeat, muscle cramps, nausea and just generally feeling unwell overall.
The only way to prevent these symptoms is to supplement electrolytes throughout your extended fast.
Do all types of fasting require electrolyte support?
Longer extended fasts (over 48 hours) definitely require electrolyte supplementation. Fasting experts and coaches all tend to agree on this point.
Shorter fasts (24-48 hours) and Intermittent Fasting / OMAD may also benefit from supplementation, but not necessarily. It depends on the individual – how much electrolytes you already have stored in your body, as well as several other factors like your genetics and lifestyle. The best approach is to pay close attention to how you feel and start taking electrolytes if and when you feel any symptoms of deficiency.
Will electrolytes break my fast?
Electrolytes are essentially mineral salts. Pure electrolytes contain no macronutrients or calories. They will not break your fast or affect your autophagy in any way.
Unfortunately, most electrolyte supplements are far from pure. Sometimes they are deliberately loaded with glucose – for example, for recovery after long runs or intensive exercise. Some products are technically sugar-free but still packed full of sweeteners, artificial flavours and junk fillers like maltodextrin.
So make sure to always check the full list of ingredients in your electrolyte supplements.
Ideally, get a product that is 100% pure electrolytes calibrated specifically for fasting. Our Fasting Salts supplement meets all of these requirements. There are several other good-quality brands on the market that are suitable.
What are the key electrolytes to supplement?
Our bodies need the following electrolytes:
- Sodium (Na)
- Chloride (Cl)
- Potassium (K)
- Magnesium (Mg)
- Calcium (Ca)
- Phosphorus (P) / Phosphate
The first three – sodium, chloride and magnesium – are the key ones to replenish during fasting.
Standard table salt (including variations like Himalayan pink salt) ticks two of these boxes as it consists primarily of sodium chloride.
There is a bit of a debate on whether potassium, calcium and phosphorus are equally essential. Different protocols and expert opinions vary on whether they are required, and at what point in the fast.
We believe that sodium, chloride, potassium and magnesium are required for optimal fasting experience.
Phosphorus appears to play a role in preventing the refeed symptom. We are reviewing the latest research on this topic and will report on our findings soon.
How much electrolytes do I need during fasting?
This is the most popular question we get! Unfortunately, there is no one-size-fits-all answer to it, whether fasting or not.
The concept of government-approved “recommended daily values” contributed to a myth that our nutritional needs are uniform. We can use these figures as a very approximate starting point. But our individual requirements for electrolytes can vary significantly based on multiple factors. In fact, they fluctuate day-by-day even for the same individual. Here are some key factors to consider.
Duration of the fast
This is probably the most important aspect.
If you are fasting for 24-48 hours or doing IF / OMAD, you might not need any electrolyte supplements at all. You might have enough stored in your body to last throughout the fasting period.
However, if you are doing an extended fast of 48 hours plus, you will definitely need to supplement. It’s best to start with a small dosage and gradually increase.
Body build and composition
If you are big and/or tall, you may need more electrolytes than someone with a smaller body. Body composition matters as well because muscle tissue, fat and bones utilise electrolytes in different ways.
If you exercise a lot, you will need more electrolytes than someone who doesn’t. We lose electrolytes with sweat so high-intensity exercise depletes your electrolyte levels quickly. Muscle recovery after anaerobic exercise also uses them up.
Medical conditions and medications
Certain medications and medical conditions (especially those related to kidneys, cardiovascular health and digestive system) may affect the level of electrolytes in your body. Supplementation may also interact with the medication in unpredictable ways.
It goes without saying that if you are on any medication or have any kind of medical condition, you should discuss fasting and electrolyte supplementation with your doctor before attempting it.
If you normally eat plenty of foods that are rich in electrolytes, you will have more of them stored in your body tissues and may require less supplementation, especially in the beginning.
Weather and climate
Sweating depletes electrolytes quickly, so you may need more electrolytes if you live in a hot climate, or during periods of hot weather.
The quality of drinking water varies widely by region. Some areas are lucky to have tap water that’s rich in electrolytes and others have hardly any. Likewise, if you usually drink bottled mineral water instead of tap water, that will provide more electrolytes.
How to find my personal optimal level of fasting electrolytes?
Some people rely on blood tests to check for deficiencies. But the level of electrolytes can vary widely day by day (for example, depending on what you ate before the test or whether you did exercise). And it’s not exactly practical to do repeated blood tests during your fast.
Because there is no “one-size-fits-all” answer, you will need to find your own optimal level of supplementation based on how you feel. If the dosage is not right – either too high or too low – it will manifest with specific symptoms.
This may seem confusing in the beginning. But most people get the feel for it after a few days of fasting.
Here’s what to watch out for in terms of symptoms:
Not enough electrolytes
- Brain fog
- Muscle cramps or weakness
- Irregular or fast heartbeat
Too much electrolytes
- Stomach pain
- Swollen ankles and fingers
Although some of these symptoms are similar, typically they manifest together.
You are likely to get at least 2-3 of them simultaneously. For example, if your electrolytes are so low that you are feeling nauseous, you will likely also have a headache and dizziness by that point.
Please note these symptoms are potentially dangerous! If you experience any of these in a severe way, break your fast, stop supplementation and consult your doctor.
What’s the safest way to take electrolytes?
Start small and build up.
We always recommend starting with a lower dosage and increasing it gradually based on how you feel.
If the dosage is too low, you can always take more later.
But if it’s too high, getting it out of your body may be unpleasant (vomiting, diarrhoea).
For example, the maximum daily dosage of our Fasting Salts is 4 scoops of powder (20g total). Most people take just 2-3 scoops and find that it is sufficient.
The safest way to take it is in smaller ½ scoop dosages. Mix with 500ml of water and take every 2-3 hours or so. If you feel the symptoms of electrolyte deficiency, try taking 1 scoop at a time – or ½ scoop more frequently.
Whereas if you try taking all 4 scoops – or even just half of that at 2 scoops – at the same time, you will almost certainly end up with stomach upset or nausea.
Many of our customers add ½ scoop to their drinking water, mixing it together in a bottle and then sipping it throughout the day. This is a great way to get electrolytes gradually which ensures optimal absorption and minimises the risk of an overdose.
How did people cope with fasting in the past without any supplements?
This is a very interesting question!
Fasting is, of course, a natural human experience that’s been with us since pre-historic times. Sometimes out of necessity due to lack of food. But often by choice – for religious, spiritual, or health-related reasons. This went on for millennia. Obviously, without any supplement pills.
The most likely explanation is that both soil and water used to be much richer in mineral salts before the advance of agriculture.
The natural cycle of food production is now broken. Minerals and other nutrients in the soil get depleted and are not given enough time and resources to replenish.
In the past, water from natural sources, like rivers and streams, would provide a lot more electrolytes than tap water in modern days. This is still the case in more remote parts of the world. Likewise, human food sources (both vegetarian and animal) would also absorb more electrolytes from water and soil.
For our fasting electrolyte products, we aim to mimic the natural way as much as possible by keeping them pure and free from junk fillers.
When is the best time of the day to take electrolytes?
For Extended Fasting (EF)
Take your electrolytes continuously throughout the day, in small dosages. Ideally every 2-3 hours or so. See the tip above about drinking water.
For Intermittent Fasting (IF) / OMAD
Take your electrolytes during your fasting window, ideally in the middle. Do not take within 1-2 hours before or after food as this may cause an overdose, especially if you had a meal that was naturally high in electrolytes.