We’re kind of a caffeine-addicted culture. Coffee, tea, soda, energy drinks…
But can you drink energy drinks while intermittent fasting?
In short, you can, but it may not be a good idea.
It also depends on the particular drink, your individual response to sweeteners, and how strict you want to be with your fasting.
Let me explain.
Avoid Energy Drinks with Sugar
Whether you’re talking about Red Bull, Monster, or some other brand of energy drink, if you drink the sugary version it’s just like drinking a soda.
And that’s definitely not okay when you’re fasting. Avoid any sugary drinks.
Be Cautious with Zero Calorie Energy Drinks
For various reasons, it’s not ideal to consume artificial sweeteners when you’re fasting.
Don’t get me wrong, it’s better to have a little aspartame than to drink something sugary. But it can certainly have its downsides, and sometimes it can completely throw you off track.
Here’s why:
Even though artificial sweeteners have basically no calories, and they don’t really raise your blood sugar or insulin levels, they can still make you get hungry or crave sweets.
Dealing with hunger when you’re fasting can be tricky, so obviously it’s better to avoid things that make you get hungrier.
Whether it’s diet soda, a sugar-free energy drink, or adding Splenda to your tea or coffee, see if you can get by without sweeteners.
The bottom line?
You’re more likely to make it through your fast smoothly without having to quit if you avoid sweeteners.
Try to Avoid Artificial Sweeteners in the Long Run as Well
As I explain in my post about diet soda and fasting, various studies have shown a connection between artificial sweetener use and health problems like obesity, diabetes, and depression (to name a few).
That doesn’t prove that artificial sweeteners cause those problems, necessarily. But it’s a suggestion that they may.
One possible mechanism is that any of these sugar substitutes cause various changes to the bacteria in your intestines, called your “gut flora”.
The constitution of your gut flora seems to be connected to your overall health, including mental health. So basically you may not want to mess around with the gut flora by putting weird artificial stuff in your body.
At least, if you do, be aware of the risks.
You Can Still Get Various Health Benefits from Fasting Even With Energy Drinks
As long as you do sugar-free energy drinks, you can still get various health benefits from fasting while you use them.
For example, if your goal is to normalize your blood sugar or insulin levels, reduce your body fat, or cure fatty liver, you can probably still accomplish that while you drink energy drinks.
That’s assuming of course that the energy drink doesn’t stimulate so many cravings that you decide to quit your fast and give up!
While it’s better to avoid energy drinks during a fast, it’s not crazy to do a self-experiment and see how your tolerance is. If you don’t get a lot of cravings, maybe it’s ok to keep using the energy drinks.
On a related note, sometimes I’ve tried drinking diet soda when I fast, and I do okay. But I’ve also noticed that my energy levels tend to be a little more steady when I avoid artificial sweeteners. Your experience may be similar.
Related Questions
To finish up, here are a few related questions you might be wondering about.
Do Zero Calorie Energy Drinks Break a Fast?
Basically the answer’s no, as long as you’re able to keep fasting.
As I mentioned above, artificial sweeteners can stimulate cravings or hunger, which might make it more difficult to fast. So in that case, you’d be a lot better off without the sweeteners.
Otherwise, drinking a zero calorie energy drink doesn’t “break” a fast–unless your goal is to do a really “clean” fast, in which case you wouldn’t use things like that.
Can You Use Energy Drinks during Extended Fasting?
Whether you’re talking about short-term intermittent fasting, or prolonged fasting, the answer is the same.
It’s “okay” to use something like an energy drink, but it might make fasting more difficult.
Furthermore, if you’re trying to be really strict (because you want to maximize autophagy for example), then you should probably avoid any sweeteners at all.
What Else Can I Drink to Get Caffeine While Fasting?
This one’s pretty easy.
Some better options that don’t contain artificial sweeteners include black coffee and green tea. Both of these seem to have some additional health benefits, and neither of them really does anything to disrupt your fast.

You could even try something like “bulletproof” coffee as well, which means adding some additional fat sources to your coffee. Just don’t go too overboard. 🙂
Summary and Final Thoughts
Can you drink energy drinks while intermittent fasting?
Yes, you can. But it’s probably not ideal.
It also depends somewhat on your individual tolerance, and your goals.
Definitely avoid any sugary drinks. When it comes to artificially sweetened drinks, including diet soda and certain types of energy drinks, they’re not ideal but some people can get away with it.
The main problem is that any sweetener can stimulate cravings, hunger, or other sensations that make it more difficult for you to continue fasting.
Artificial sweeteners have also been linked to variou harmful long-term effects like obesity, diabetes, and depression. So it’s probably better to avoid them anyway.
However, if you find drinking a zero calorie energy drink doesn’t really disrupt your fast, then it may not be the end of the world. You can certainly still get a lot of health benefits from fasting under those conditions.
Like a lot of things, you may need to do some self-experimentation and see what works for you. Each person is a little different so the answer is not always the same.
Happy fasting!