I’m a huge fan of fasting and intermittent fasting.
It’s pretty easy to implement in your life once you get rolling, and it has a ton of benefits like:
- Easier to lose fat
- Effortless to maintain your weight
- And helps you form a more mindful relationship with food
That said, fasting isn’t always easy.
It can get a little bit tough to stay focused toward the end of a long fast, especially if you do 18, 20, 24-hour fasts or longer.
Luckily, there are lots of things that can make it just a little bit easier.
So what are the best supplements to take for fasting?
In no particular order, you should consider trying:
- Ketone base (My recommendation)
- Fast-compliant pre-workout (My recommendation – Amazon link)
- BCAAs (branch chain amino acids) (My recommendation – Amazon link)
Full disclosure: You (probably) won’t need all of these!
Usually, all you need to get through a basic 16 hour fast is some water and maybe a little sparkling water.
But if you’re struggling or routinely doing longer fasts, you might want to check out the benefits of supplementing your fasts with a few of these.
What does and does not break a fast?
Let’s get this out of the way first before we talk fasting supplements.
What can you have on a fast?
We know that any solid food is out. And we know that plain water is good.
But what about things with flavor, artificial sweeteners, and low-calorie drinks?
Let’s break it down.
There are basically two schools of thought as to what’s OK to have during a fast.
Fasted vs Fed:
In this school of thought, the primary goal is to prevent your body from going into a “fed state.”
The main idea is to suppress the need to digest food. So really any liquid under 50 calories or so is fast-compliant (like bone broth).
(In a fed state, your body is processing calories. In a fasted state, it’s not. Pretty simple. Under-50 calorie liquids are processed by your body so easily and quickly that you never truly enter a fed state.)
This is a pretty loose way to fast, and it’s really convenient and easy to follow. This is the method I personally use, though I tend to avoid anything with any calories at all with the exception of a pre-workout that might have about 5 calories per serving.
In this method of fasting, anything that might cause an insulin spike in your body (basically, your body getting ready to digest food and, in particular, carbohydrates) breaks the fast and knocks you out of fat-burning ketosis mode.
A lot of artificial sweeteners are a no-no here because they trick your body into thinking it’s having sugar.
Research is mixed on this, however, and different kinds of artificial sweeteners seem to have a different impact on insulin and blood sugar levels. Most proponents of fasting will advise you to stay away from too many artificial sweeteners to be safe.
Now let’s get into some supplements you might want to consider taking before or during your fasts.
1. Caffeine / Coffee
Hey, ready for some good news?
For most of our purposes, having some black coffee during a fast is totally OK.
(Black coffee will not break a fast.)
And guess what else? There are a ton of other benefits to having caffeine, specifically from coffee:
- Blunts your appetite and makes it easier to continue fasting
- Upregulates ketosis (fat-burning for energy)
- Helps stabilize blood sugar and insulin levels, lowering your risk of type 2 diabetes
- Is delicious and comforting to drink
The key is that in order to be fasting-compliant, you can’t put any milk, sugar, cream, butter, or other calories into the coffee.
(A tiny splash of milk might be fine if you’re using a looser fasting method.)
You can always grab some caffeine from a diet soda, too, if you just need a bit of a boost. But remember to try and limit your artificial sweetener intake on a fast.
2. A multivitamin
This probably isn’t something you’ll need to worry about during shorter or intermittent fasts.
Taking a multivitamin in the morning during intermittent fasting is overkill and not necessary.
But for longer fasts of over 24-hours, it might be good to stock up on vital vitamins, minerals, and nutrients in your body before you enter the fast.
(Vitamins go best with food for absorption. Taking them on an empty stomach robs you of some of the benefits and can upset your stomach.)
Once you’re in a fasted state, there’s really no need to supplement with vitamins. Most of what your body needs will already be stored and can be accessed as you enter a catabolic state.
There’s even some evidence that going into a temporary micronutrient deficiency can actually help your body become stronger.
Just be sure you’re eating nutritious food before and after your fasts. And if you’re deficient in any particular vitamins, stock up with a solid multi-vitamin before entering a long multi-day fast.
3. Electrolytes (Sodium, Magnesium & Potassium)
This is probably one of the most important ones on the list.
Have you ever noticed that you pee more during intermittent fasting?
Like, a LOT more?
I always thought it was because I was drinking coffee, water, and sparkling water on an empty stomach, causing it to run right through me. (Which is still true.)
But there’s also this:
The longer you fast, the lower your insulin levels go, and that signals your body to flush away crucial electrolytes (potassium, sodium, and magnesium). This is all part of the ketosis process.
However, peeing a lot sucks! And losing all of that water can leave you dehydrated and low on energy.
So in addition to drinking plenty of water during your fast, consider supplementing with some crucial electrolytes.
One easy way to get more sodium is to add a little bit of salt to your water and chug (gross, I know, but effective).
The good news is that getting that extra sodium will help your body hold on to potassium more easily. And for longer fasts, you can add in a simple magnesium supplement to round things out.
Or you can try…
4. A fast-compliant pre-workout
There are a lot of great reasons to use a pre-workout when fasting, especially if you’re, you know, working out.
A good pre-workout will kick you in the teeth with some huge benefits, including:
- Plenty of caffeine to boost your energy and mood
- More strength and power in the gym
- Better recovery post-gym
- And some crucial vitamins and minerals to keep your fast going strong
Just be on the lookout for hidden calories in pre-workouts! Most of them are around 0-5 calories per serving, which should be fine. But you should be aware that techically a 5 calorie pre-workout may break your fast, depending on how you keep track.
My favorite pre-workout is, hands-down, Kino Octane by Kinobody (get it on Amazon through the link).
In addition to just being a great pre-workout, it’s specifically designed for people who are using intermittent fasting and is loaded with extra electrolytes to keep you hydrated and energized throughout the day.
It’s what I use, and I love it!
5. A Ketone base
One of the main benefits of doing intermittent fasting is that it puts your body into ketosis, or the process of turning fat into energy instead of carbohydrates and stored glucose.
Now you can actually take a supplement during your fast that contains ketones (energy units) and kicks your ketosis into overdrive.
Check out Exogenous Ketone Base from Perfect Keto (use code APERFECT15 for a super easy 15% discount on your first order).
It’s sweet-tasting, comes in 5 different flavors, and won’t break your fast with calories or an insulin spike.
It’s designed to get you into ketosis faster or keep you there longer, while tasting great and boosting your energy levels, mood, and focus.
If you’re regularly doing long fasts or struggling to adapt to the Ketogenic diet, definitely check this out.
6. Branch chain amino acids (BCAAs)
If you’re doing intense workouts while in a fasted, empty-stomach state, I HIGHLY recommend you look into taking BCAAs before the gym.
One of the downsides to fasting and doing fasted workouts is that, sometimes, your energy level just isn’t there. Fatigue sets in and it’s harder to push through to the end of tough workouts.
BCAAs help reduce that fatigue and protect your muscle from too much breakdown while you crush it in the gym.
They’re a really important supplement for building or maintaining muscle through exercise while fasting.
(If you’re fasting but not doing much in the way of working out, you won’t really need these.)
Here’s my favorite BCAA (Amazon link), specifically designed to fuel fasted training.
For shorter fasts like 16, 18, or even 20 hours, there’s not a whole lot you really need.
It’s not super difficult to make it through a short fast like that.
For full day and especially multi-day fasts, or when just beginning to transition to the Ketogenic diet or intermittent fasting, you may need some help in your arsenal.
I’d say the most important thing is to make sure you’re well-hydrated and loaded with the right electrolytes. That’s why my favorite thing to drink during fasting is Kino Octane (Amazon link) because it hits you with energy and electrolytes at once!
But again, most of what I’ve mentioned is completely optional, though it might make your life quite a bit easier.
Best of luck during your fasts, friends! And I hope this has helped.