Does an Artificial Sweetener like Stevia or Sucralose Break Your Fast?
Does an artificial sweetener break a fast? (Photo: Adobe Stock)
Human Window Staff
By Human Window Staff
Updated on September 30, 2019

If you practice intermittent fasting on a regular basis, then it’s pretty important that you know what does and doesn’t break your fast. So where do artificial sweeteners fit into the equation?

Many people who fast regularly will also consume products that use sweeteners such as stevia or sucralose.

But will these sweeteners kick you out of a fasted state and what do you need to be aware of?

If you’re looking for the answers to these questions, then the chances are, you’re looking to find out whether you can get away with consuming a supplement or drink that uses sweeteners during your fasting window.

This article is going to take a detailed look at artificial sweeteners, intermittent fasting, and whether the two can be used together or not.

We’re going to get into detail about the basics that you need to know about intermittent fasting, and whether having a sweetener while doing it is a good idea or not.

So, with the introductions out of the way, let’s start taking a closer look at whether an artificial sweetener breaks you fast or not.

What is Intermittent Fasting?

In its simplest form, Intermittent Fasting (IF) is simply a general term for various eating patterns that involve fasting (not eating) for short periods of time.

For people who don’t practice it regularly, the word ‘fast’ can make it sound more dramatic than it actually is.

In truth, it just means reducing the ‘window’ in which you eat food during the day.

Intermittent Fasting
(Photo: Adobe Stock)

Simply put, intermittent fasting means that you will be eating your meals in a shorter time window than normal.

There are many different protocols when it comes to intermittent fasting, ranging from the extreme to the easy to follow.

One popular intermittent fasting method is a daily 16-hour minimum fast with an eight-hour ‘eating window’.

This simply means that you would stop eating at, say, 8pm in the evening. And you then would not eat anything until 12pm the following day.

What ‘fasting’ means, generally speaking, is not consuming any calories. That means that during a fasting window, you would not eat any food or drink any beverages that contain calories.

Most people accept that some black coffee or tea (with no sugar or milk) will not break a fast, even though they do contain a small number of calories.

There are various debates about whether certain supplements will break your fast or not. Generally speaking, if they contain calories, they will break a fast. For more information, check out our guide to whether pre workouts break a fast.

You may, at this point, be wondering what the benefits to intermittent fasting actually are and why you might want to practice it regularly.

There is an increasing amount of research emerging that suggests incorporating some form of intermittent fasting into your daily or weekly routine could bring about some pretty significant benefits.

We’re not going to go into too much detail here about the science behind it. If you’d like to know more about fasting and its potential benefits, then we recommend you take a close look at our dedicated guide here at Human Window.

If you’d like to learn more about intermittent fasting and the potential benefits it can bring, check out our interview with 2 Meal Day founder Max Lowery. It’s also worth hearing what Siim Land has to say on fasting and metabolic autophagy.

The Bottom Line: Intermittent Fasting is the name given to the practice of sticking to eating patterns that involve fasting (not eating) for short periods of time. It is believed to have a number of health benefits. There are numerous intermittent fasting protocols. A simple and easy to follow one is a a daily 16-hour minimum fast with an eight-hour ‘eating window’.

What is an Artificial Sweetener

So, now that we’ve covered the basics about intermittent fasting, it’s time to take a closer look at artificial sweeteners.

Simply put, artificial sweeteners are low-calorie or calorie-free chemical substances used instead of sugar to sweeten foods and drinks. They are also used in certain supplements such as pre workouts.

There are lots of different types of artificial sweeteners out there, including the likes of aspartame, sucralose, stevia and xylitol.

Many pre workout supplements use sweeteners (Photo: Adobe Stock)
Many pre workout supplements use sweeteners (Photo: Adobe Stock)

Some of the perceived benefits of artificial sweeteners is that they can have less effect on blood sugar levels, and also may help prevent tooth decay, when compared to actual sugar.

Simply put, artificial sweeteners can help to improve the taste of certain products, like protein powders and pre workout supplements. However, most of them do not increase blood sugar levels, which is seen as a positive factor.

The Bottom Line: Artificial sweeteners are low-calorie or calorie-free chemical substitutes for sugar that are added to food and drinks for taste. They are also used in certain supplements. Most sweeteners do not increase blood sugar levels like actual sugar does, and the use of them instead of sugar may help to prevent tooth decay.

Does an Artificial Sweetener Break Your Fast?

So, now that we’ve covered the basics about Intermittent Fasting and Artificial Sweeteners in general, it’s time to see whether a sweetener will break your fast or not.

If you’ve done any research for yourself, then you’ll know that there is plenty of conflicting research out there when it comes to artificial sweeteners and health.

Whether a sweetener breaks your fast or not comes down to whether it contains calories or triggers an insulin response in the body.

As most sweeteners are designed to be low or zero calorie, and also not raise blood sugar levels, it’s often assumed that sweeteners do not bring you out of a fasted state.

The truth, however, is not crystal clear. Yes, some sweeteners are designed to have no calories and not trigger an insulin response. But your body will still have to process them in some way or another.

There is no definitive answer to whether a sweetener will break your fast or not. On paper, they appear not to, but we recommend steering clear of them during your fasting window.

A lot of the answer to this question will depend on how strict you’re being when it comes to your intermittent fasting protocol.

Simply put, if you’re looking to ensure that you are staying in a fasted state, then we don’t recommend consuming any supplements, food or drinks that contain artificial sweeteners.

The only way to 100 per cent guarantee that you will remain in a fasted state is to only drink water during your fasting window.

That said, most people accept that drinking black coffee or black tea is acceptable, even though both drinks do contain a small number of calories.

Although sweeteners are deemed to be safe by authorities in the EU, we would always much prefer to be getting our nutrition from natural sources rather than something man-made.

The Bottom Line: Although sweeteners are claimed not to contain any calories or trigger insulin responses in the body, we recommend staying away from them if you want to be sure of staying in a fasted state. If you want to be sure that you’re staying in a fasted state, then only consume water during your window. On top of this, we’re not big fans of artificial sweeteners in general and we prefer to consume natural foods as opposed to man-made ones.

A pre workout supplement drink (Photo: Adobe Stock)
A pre workout supplement drink (Photo: Adobe Stock)

Anything Else to Consider?

As we mentioned above, the only way to be 100 per cent sure of remaining in a fasted state is to only drink water during your fasting window.

If you’ve landed on this article looking for information about artificial sweeteners and fasting, the chances are that you are looking to see if you can get away with consuming a supplement or low-calorie drink during your window.

We would recommend not to do so and instead stick to just water – and black coffee and tea if necessary.

That being said, if you are not too fussed about being 100 per cent accurate with your fasting window, then consuming some sweeteners here and there would probably not make a huge difference in the long run.

We always strongly recommend that you speak to a certified medical professional before beginning any fasting protocol.

Conclusion – Our Final Thoughts

So, that brings us to the end of our look at artificial sweeteners and intermittent fasting.

On paper, most sweeteners will not bring you out of a fasted state.

However, we recommend not to consume sweeteners or anything else other than water, black coffee and black tea during your fasting window if you want to be sure of seeing the benefits.

Best pre workout supplements
We've picked out the top five leading pre workout supplements on the market right now.