What Can I Drink While Fasting? [What Helps, What Hurts]

Sure, fasting means not eating…but what can you drink while fasting?

Today I’ll share with you some drinks that are helpful, harmful, or kind of neutral while you fast.

By understanding which drinks fall into each category — and why — you’ll be better prepared to make solid decisions and have success with fasting.  

Let’s get started.  

Video & Podcast Versions

In case you prefer, I also covered what to drink while fasting in a video (below), as well as a podcast episode.

But if you prefer reading…carry on. 🙂

Can You Drink Water While Fasting?

Yes.  I almost always drink water when I’m fasting, and I recommend you do the same.

That’s true for short-term “intermittent” fasting (< 24 hours), as well as multi-day “extended” fasting.

By the way, sometimes extended fasting is referred to as “water fasting”.  That just means you keep drinking water while you fast.

Technically, there’s also something called “dry fasting”, which prohibits water.  But I wouldn’t really recommend that for beginners, especially if you’re fasting for multiple days.

Some people prefer dry fasting, but it’s a little more risky, and requires more medical supervision.

So in general, keep drinking water and try to stay hydrated.

Drinks That Make Fasting Harder

Some drinks make fasting more difficult.  Or they’re just bad for your health.  Or both.  

In this section, I’ll cover a few of the drinks you should avoid during intermittent fasting or extended fasting. 

Avoid Sugary Drinks While You Fast

You really shouldn’t drink anything with more than a tiny amount of sugar while you’re fasting

That includes soda, juice, sports drinks, and others.  

Make sure you look at the nutrition label and the ingredients list.  If there’s more than about one gram of sugar, you should probably avoid it.

That’s because anything with sugar in it will raise your blood sugar, and also raise your insulin level. 

Insulin is a metabolic hormone that goes up whenever you eat carbs, and one of its main jobs is to promote fat storage. 

If you’re not familiar with insulin, this short video covers some of its basic functions:

Any time you’re stimulating insulin, that’s basically the opposite of fasting.

See why “juice fasting” is an oxymoron? 😉

Artificially Sweetened Drinks Are Not Your Friend

I used to drink diet soda sometimes while I fasted.  And I did ok.  But last year I decided to quit artificial sweeteners, and I think it was a good decision.  

That’s because artificial sweeteners (like aspartame or sucralose) seem to be pretty bad for your long-term health. 

And perhaps more importantly in the context of fasting, artificial sweeteners can stimulate cravings or hunger.

So if you drink a Diet Coke in the middle of your fast, you may start craving sweets and give up.

“Natural” sweeteners (like stevia, erythritol, or monk fruit) are probably healthier options.  But any sweetener can stimulate cravings, so be cautious.

Bottom line?

Fasting gets easier when you avoid artificial sweeteners.

If you have a longstanding habit with diet soda, energy drinks, or anything similar, it may take a while to wean yourself off.  But it’s probably worth it.  

Alcohol Presents Problems

This one is pretty simple.

Most alcoholic drinks have sugar and/or other carbs. So they’re not ideal for fasting.

Your body will probably also be more sensitive to alcohol when you fast.

So while you could use sugar-free alcoholic drinks (like spirits / hard liquor), you’d need to stick with tiny amounts.

Bottom line?

Overall, it’s probably best to avoid alcohol while you fast.

These Drinks Are “Okay” (& May Have a Small Benefit)

A lot of drinks are kind of “neutral” when you’re fasting.  Or in some cases they may have a small benefit, like helping suppress your appetite.

These kinds of drinks are optional.  But they’re okay to use during both short-term and long-term fasting.

Let’s look at a few examples. 

Black Coffee Is Fine

It’s totally ok if you wanna drink plain black coffee while you fast.  A lot of people do well with it, and it may help suppress your appetite.

On the other hand, once you start adding sugar or sweeteners to your coffee…that’s when you can get into trouble (see above).

Of course, there’s a lot of caffeine in coffee. So try not to go overboard, especially later in the day, or you may have trouble sleeping.  

And since caffeine makes you pee out more water, it’s probably a good idea to drink a glass or two of water for each cup of coffee that you drink.

What About “Bulletproof” Coffee?

“Bulletproof” coffee (a.k.a. “keto coffee”) just means you add some type of fat to your coffee.

This could be butter, MCT oil, or even the more traditional coffee with cream.

Here’s the scoop on coffee + fat:

Fat-infused drinks can raise your ketone levels (which is good!), and give you an energy boost while you fast.  And they don’t really “break” your fast, necessarily, because dietary fat doesn’t raise your blood sugar or insulin levels.

But the more fat you consume while fasting, the less of your own body fat you’ll burn.  So there’s always a trade-off.

It’s probably better to think of fatty drinks as a type of “training wheels” that you can use when you’re a beginner.  

But maybe not forever.  

Green/Black/Herbal Tea is Ok (& may have some benefits)

I often drink tea while I’m fasting, and haven’t noticed any harmful effects.

As long as you don’t add sugar or other sweeteners, it shouldn’t really cause any problems. 

The best part?

Green tea may make fasting a little bit easier, and even enhance some of the health benefits. 

Like coffee, green or black tea have a fair amount of caffeine. So try not to overdo it in the 2nd half of the day.

More “Okay” Options

If you’re looking for additional drink options while fasting, here are a couple more ideas:

Apple Cider Vinegar

Basically, as long as you don’t go too crazy, it’s fine to use vinegar while you fast. And some people find it helps control their appetite.

It’s pretty acidic though, so make sure you dilute it in some water.

Lemon Water

Lemon water (a slice of lemon squeezed into a glass of water) is also a good option, as long as you don’t totally overdo it.   

A few glasses per day should be fine.

Seltzer Water

If you like carbonation, you may want to try a seltzer water (a.k.a sparkling water, or soda water).

Unlike diet soda, it shouldn’t have any sweeteners, so it’s less likely to cause cravings.

On the other hand, it does have “natural flavors” and carbonation, which can cause issues for some people. So be cautious.

Like anything, it’s an experiment. So see how you react, and go from there.

How can you tell if something else is okay to drink while fasting?

If you’ve read this far, you probably have a pretty good idea already.

Basically, if there’s not a lot of sugar (or sweeteners), and not too many carbs or total calories, you’re probably fine.

What “breaks” a fast varies from person to person, depending on your goals and health status.

Here’s are some rules of thumb I typically use:

1. Keep carbs (including sugar) down to about 1 gram per serving
2. Keep calories as low as possible – ideally under about 10-20 per serving
3. Be careful with sweeteners, and don’t overdo it

The main exception would be if you’re using some type of “training wheels” to make fasting easier as a beginner.  And that’s totally reasonable to do. 

Training wheels include things like bulletproof coffee, bone broth, MCT oil, and various others.

The common theme is they’re all low in sugar / carbs, but have extra calories because of the fat or protein content.  That’s why they can boost your energy without significantly raising your insulin or blood sugar.

So as long as you don’t overdo it, they won’t disrupt your fast too much. 

Keep in mind, using training wheels constitutes a kind of “dirty” or “modified” fasting, and some people are opposed to that approach.  

But I think when you’re first starting out, anything that makes fasting easier is worthwhile.  You’ll still get a ton of health benefits, and you can always “clean” things up later on.  

(For more on how to make fasting easier, you can download my Beginner’s Guide to Easy Fasting.)

Drinking Salt & Other Minerals Makes Fasting EASIER

In addition to the smallish benefits you can get from vinegar, tea, or other drinks listed above, there are also some drinks that make fasting A LOT easier.  

The biggest one?

Anything with lots of SALT (i.e. sodium).

This is especially relevant for prolonged, multi-day fasting. But getting enough salt can also be helpful during short-term fasting, or even when you eat a ketogenic diet.

To understand why, keep reading.

Why Does Salt Make Fasting Easier?

As researcher Ben Bikman explained in his recent book, most Americans have chronically elevated insulin (a.k.a. insulin resistance) from all the processed carbs we eat.  High insulin makes us retain a lot of salt and water.

As a result, many of us are accustomed to having high blood pressure.  Even though it’s not normal, that’s what our brains and bodies are used to.      

When you fast for several hours (or eat a low carb diet), your insulin goes down a little bit.  

When you fast for a few days, your insulin goes down a lot, and you pee out significantly more salt / sodium than you’re used to.  

Whoosh.  

As your sodium drops, so does your blood pressure. So you may feel kind of light-headed or fatigued.  Or have other symptoms.   

Low sodium levels also cause your stress hormones (like cortisol and adrenaline) to go up,  which can make you feel anxious and have a harder time sleeping. 

By getting plenty of salt during a prolonged fast, you can prevent these issues.

Salty Drinks You Can Use While Fasting

Technically, you don’t have to drink your salt. You could basically just eat it.

But I find some of the salty liquids to be more palatable  

Basically you want something very high in sodium, but low in carbs, and low in total calories.

My main go-to is bouillon.  That’s because it’s cheap, readily available, and fits the above criteria perfectly.

For example, one bouillon cube has about 800 mg of sodium, but only 5 calories (which is basically negligible).

Just dissolve it in some hot water, and voilà.

Another good option is veggie broth.  The type I use has about 750 mg of sodium per serving, but only 5 calories.  So almost exactly the same as a bouillon cube.  

Another quick and easy sodium source is soy sauce. It usually has about 1 gram (1,000 mg) per serving, but only 10 or so calories.  You can either just splash the soy sauce in your mouth and wash it down with some water, or mix it in with a drink.

It doesn’t exactly taste good.  But it can boost your sodium in a jiffy. 

Sometimes I eat dill pickles as well.  They also have quite a bit of sodium, but almost no calories.

Hopefully you get the idea.

I’ve done prolonged fasting with and without extra salt, and I feel WAY better when I add salt.  

Here are some salty examples I happened to have on hand: 

I usually try to get at least 2 or 3 grams (2,000 – 3,000 mg) of sodium per day during a prolonged fast.  For most people, that may be enough to keep your blood pressure in a happier place.    

Sometimes I go even higher (like 4 or 5 grams per day).

Since I’m relatively young and healthy, I don’t have to worry a whole lot about getting too much sodium while I fast.  I’ll basically pee out any excess after a while, as long as I keep drinking water.  

It’s a balance though, so experiment and see what works for you.  And take it slow with any changes you make, so you can see how your body adapts.    

You probably don’t need as much of a salt boost if you’re just doing daily time-restricted eating (a.k.a. intermittent fasting).  But even then getting a little extra can make you feel better.  

A Medical Disclaimer Seems Relevant Here…

If you’re suffering from kidney failure, heart failure, or other chronic illnesses, make sure you consult with a qualified medical professional before you start ramping up your sodium intake.

In general, fasting is a totally normal human activity.  But you may need medical supervision if you’re fasting while on prescription medications (especially for diabetes or blood pressure), or have certain other health challenges.  Full disclaimer.  

Other Electrolytes Can Also Make Fasting Easier

They’re not nearly as important as sodium, but taking some other electrolyte supplements can also be helpful.

Mainly this means magnesium, and potassium.

Basically, by getting some extra potassium and magnesium (along with your sodium!), you can lower your chances of getting things like muscle cramps or palpitations that occasionally accompany prolonged fasting.

If you have normal kidney function, you don’t have to worry too much about the amount – you mostly pee out any excess.

I use some powder supplements that I ordered online, and I take a little bit each day when I do a multi-day fast.

One word of caution about magnesium-

In some people, extended fasting can cause loose stools. Taking a lot of magnesium by mouth can also cause diarrhea. So obviously, that’s a potential double whammy.

Probably the best forms of magnesium to prevent diarrhea are magnesium glycinate and magnesium bisglycinate.  Lately I’ve been using both of these in powder form, without any problem.  

Yet another way to get magnesium is to take an Epsom salt bath. The magnesium in the Epsom salt gets absorbed through your skin, so it doesn’t cause any GI side effects at all. 

Are Electrolyte “Combos” a Good Idea?

They might help, but there’s one main problem-

Because they’re trying to combine sodium, magnesium, potassium, and other minerals all into one supplement, there’s usually not NEARLY enough sodium.

One thing you could do would be to use a combo supplement, but also get some extra salt from other sources.

Remember, if you have normal kidney function you probably want at least a couple of grams of sodium per day during an extended fast. 

Conclusion

To make fasting as easy and beneficial as possible, there are some drinks you should avoid.  That mainly includes sugar, artificial sweeteners, and alcohol.

Certain other drinks are “okay”, and may even have a small benefit.  This includes black coffee, tea, and apple cider vinegar, to name a few.  

You can also use some basic criteria to figure out if any other drink is a reasonable option.

Extended fasting is a lot easier if you keep your electrolyte levels up.  Sodium is BY FAR the most important, but magnesium and potassium can also help.

Electrolyte supplementation is less important during time-restricted eating (a.k.a. intermittent fasting), or even ketogenic diets.  But it’s still worth considering.  

Hopefully now you’re better prepared to answer the question, “What can I drink while fasting?”

Lastly, if you found this article helpful, please share it!  Don’t be selfish. 😉