What Can You Drink while Intermittent Fasting and What Breaks a Fast?

By HumanWindow
Updated on 4 May 2023
Expert Content

What breaks your fast? This is one of the most common questions around when it comes to Intermittent Fasting.

Intermittent Fasting has become incredibly popular in recent years as more and more people look to take their health and fitness journeys to the next level.

But the question about what does and doesn’t break your fast seems to be one of intense debate. For example, does a pre workout supplement break your fast?

In this article, we’re going to take a close look at the things that will break your fast, and what is safe to consume while fasting that won’t bring you out of the fasted state.

We’re also going to bring you an expert comment from Intermittent Fasting expert Max Lowery for a detailed answer to this specific question.

So, with the introductions out of the way, let’s start taking a closer look at what breaks your fast.

Editor's note: The content on this website is meant to be informative in nature, but it should not be taken as medical advice. Our articles and the products featured in them are not intended for use as diagnosis, prevention, and/or treatment of health problems. Always speak with a certified medical professional before making any changes to your lifestyle, diet, exercise routine, and/or taking any supplements.

What is Intermittent Fasting?

If you’re reading this article, the chances are you already know about the basics of Intermittent Fasting, but let’s quickly cover the basics anyway.

Intermittent Fasting is simply a general term given to various eating patterns that involve fasting (not eating) for short periods of time.

For example, you may choose to split your day into a 16-hour ‘fasted period’ and an eight-hour ‘eating window’.

Intermittent Fasting is believed to have a number of health benefits, and it has become a popular diet trend over the last few years.

Intermittent Fasting

(Photo: Adobe Stock)

There is more scientific research emerging which suggests that fasting could be beneficial at helping to improve overall health.

Many people also choose to try Intermittent Fasting because of its link to weight loss.

What Can You Drink while Intermittent Fasting?

First things first, you can drink as much water as you like while Intermittent Fasting.

Generally speaking, it is also widely considered to be fine to drink Black Coffee (with no sugar or milk) and things such as Green Tea and Herbal Tea (again, without milk or sugar).

Coffee and Caffeine

Black Coffee (Photo: Adobe Stock)

The reason why these drinks are usually permitted while fasting is because their calorific content is usually negligible.

Things such as fruit juice or smoothies will break your fast, as they contain considerable numbers of calories.

‘Zero calorie’ sodas and drinks often contain artificial sweeteners which could bring you out of a fasted state. Generally speaking, we advise to stay away from these types of products, as we are not fans of artificial sweeteners in general.

So, to summarize, water is definitely OK. Herbal Teas and Black Coffee without milk or sugar are also generally considered to be OK during your fast.

What Breaks Your Fast?

As we touched on above, the answer to the question of what breaks your fast is usually down to whether the substance in question contains calories or not.

Things such as fruit juice, smoothies or protein shakes will definitely break your fast. And obviously any food will also break your fast.

There is quite a bit of debate about which supplements break your fast or not. There is no definitive answer to this question, as it depends on the product in question.

That being said, if a supplement contains things such as sweeteners, or anything else that could contain calories, then it is likely to break your fast.


(Photo: Adobe Stock)

Protein shakes will definitely break your fast as they contain calories and usually some form of sweetener.

Some people take BCAA (branched chain amino acid) supplements while fasting. Although they may have benefits, there is some debate about whether they could break your fast. If you’re in doubt and want to make sure that you’re not breaking your Fast, then do not take BCAAs while Intermittent Fasting.

The general rule to remember when it comes to working out what breaks your fast or not is that if it contains calories, it will probably bring you out of the fasted state.

If you are keen to make sure that you won’t be breaking your fast, our advice it to stick to just drinking water during your fasting window.

That way, you can be 100 per cent sure that you’ll remain in a fasted state.

Expert Comment

Max Lowery

Max Lowery (Photo: Tom Joy)

We spoke to Intermittent Fasting expert and personal trainer Max Lowery to get his thoughts on this specific question.

We asked Max what does and doesn’t break your fast, and this is what he said.

Max says: “I work closely with somebody called Dr Adam Collins, who is a professor of nutrition with more than 30 years’ experience in the field and is based at Surrey University.

“He has done specific research on fasting and how it affects the body, the body clock, and how when you eat changes things.

“I’ve asked him this specific question (about what you can have while fasting), and essentially you’re fine to drink as much water as you like.

“Black Coffee is fine, Green Tea is fine, Herbal Tea is fine. There will be a thermic effect of these things on the body, so your body temperature might increase but that won’t take you out of the fasted state.

“A splash of milk is probably fine in your Tea or Coffee. But it really depends on what your goals are (from Intermittent Fasting).

“If your only goal is weight loss, then having a splash of milk in your Coffee or Tea is not going to stop you from losing weight.

“But if you’re looking at getting the digestive benefits, the insulin sensitivity benefits and resetting your body, then maybe you should be a bit more strict with it.

“When you start adding butter, and other things, into Tea and Coffee, that certainly takes you out of your fasted state.

“The reason they do it with [things like] Bulletproof Coffee is because it’s pure fat. You’ll still be burning fat, but you’ll be out of the fasted state. You are upping the calories a bit and it’s allowing people to not eat for a bit longer.”

Anything Else to Consider?

As always, we think that it’s important not to get too hung up on the specific details.

If you’re looking to get the health benefits of Intermittent Fasting, then you should probably stick to a water-only fasting schedule, that way you can be 100 per cent sure that you’ll remain in the fasted state.

Things such as Black Coffee and Green Tea should be fine to be consumed while fasting, within reason.

It’s also important to make sure that you’re sticking to a good diet, getting plenty of rest and training regularly.

Intermittent Fasting can be a great tool to help you achieve your fitness and health goals, but overall balance is important.

We always strongly recommend that you speak to a medical professional before thinking about trying Intermittent Fasting for the first time.

Does Pre Workout Break Fast?

(Photo: Adobe Stock)

Wrapping Things Up – Our Final Thoughts

So, that brings us to the end of our look at what you can drink while Intermittent Fasting and what breaks your Fast.

We’ve covered the basic facts about Intermittent Fasting and have also looked at some of the substances it should be safe to consume without bringing you out of the fasted state.

You can drink as much water as you like, and things such as Green Tea, Herbal Tea and Black Coffee should also be OK.

All protein shakes will break your fast, and some supplements which contain calories or sweeteners are also likely to bring you out of the fasted state.

If you’re looking for a 100 per cent guaranteed way to make sure that you are not inadvertently breaking your fast, then sticking to a water-only fast is a proven and effective option.

As Max mentioned in his comment, it’s all about your goals. If you’re looking to lose weight, then small things such as a splash of milk in your Coffee will not be a big deal.

However, if you’re looking to reap the other health benefits of Fasting, then you may want to be more strict with it and stick to water only while on your Fast.

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