Does lemon water break a fast?

I am standing here in my kitchen, 14 hours into my fast and about to drink this refreshing water with freshly squeezed lemon juice while I am suddenly wondering: wait… will this lemon water break my fast? Needless to say, this is not my intention. Let’s dive deeper into this question and see if yes or no I am about to break my fast this morning, earlier than anticipated.

Lemon in body of water

Short answer

If you want the short answer right away, here you go: no, lemon water will not break your fast. The main reason is that it will not spike your insulin level as there are too few calories into this drink. That’s why it won’t have an impact on your fasting state.

Now let’s dive a little bit deeper into what fasting actually means and what are the variable factors to take into account.

Fasting overview

What is fasting?

You might have heard of intermittent fasting or even started doing it already as it is becoming more and more popular based on the health benefits it can provide. But what is it exactly?

Fasting is the willful refrainment from eating any food or other forms of calories for a certain period of time. Hence, intermittent fasting is a general term that covers diverse eating behaviors involving fasting for short periods of time. We can also refer to it as time-restricted eating. In a way, you simply decide when you eat and restrict it to a specific time period.

There are various ways of practicing intermittent fasting like the 16/8 method which involves fasting for 16 hours and eating during an 8-hour time frame. Eat-stop-eat is another interesting method that involves a 24-hour fast twice a week. Or alternate-day fasting involves a 24-hour fast every other day. There are other various ways of practicing intermittent fasting if you want to learn more about this.

What happens in your body when you are fasting?

First of all, after we ingest food or drinks that contain carbohydrates or glucose, the level of glucose in the blood will rise. In response to that rise, the pancreas will release a hormone called insulin, to gradually decrease that blood glucose level. Insulin will enable the glucose to enter the body’s cells, where it will be either burned for energy or stored as glycogen or fat.

Between meals, as long as we don’t eat anything else, our insulin level goes down. The fat cells will then release their stored sugar in order to be used as energy. The level of insulin when fasting is < 174 pmol/L.

What leads to breaking a fast?

When we eat, blood glucose level will rise after carbohydrates are broken down into glucose and other simple sugars and enter the bloodstream. Insulin will then be released in two phases: one right after the food is eaten, for about 15 minutes; the other one is more gradual over the next 1 to 3 hours. Insulin level will rise within a range of 125 to 1900 pmol/L based on the time after eating and come back to a level lower than 174 pmol/L after 3 hours (more details here).

Breaking a fast means that your insulin level will spike up over that standard fasting level and your body will work towards decreasing that blood glucose level. This is literally triggered by the calories ingested.

While strictly speaking, staying as close as 0 calorie is best during a fast, the general rule of thumb is that with fewer than 50 calories, you will remain in a fasted state. Whether this number is totally exact is still to be proven, but overall a little amount of calories won’t likely spike your insulin enough to impact your fasting state.

What lemon water does to your body?

Before going into its impact on fasting state, it’s important to understand why we want to drink lemon water in the first place.

Lemon water has indeed various health benefits. Lemon is rich in vitamin C which is a powerful antioxidant, it helps support your immune system and is involved in a lot more body functions. It also promotes digestion, can fight bloating and reduce kidney stone risk.

Among other benefits, the taste of lemon water itself can also help alleviate hunger, which is always helpful during a fast.

Slice lemon cut with a knife on a board

So does lemon water break a fast?

As we already eluded earlier, no it won’t break your fast. The calorie content is too small to trigger an insulin spike. However, like everything, it doesn’t mean we can go crazy on the amount of lemon juice we add in the water. Be reasonable. The table below will help you have an understanding of calories count related to lemon water.

Calories count examples

Let’s look at a few examples of calories count for lemon water:

Number of calories Does it break your fast?
1 tablespoon3No
1/2 lemon yield6No
1 lemon yield12No
1/2 lemon yield with
1 tablespoon of honey

It all depends on the quantity

As you can see in the table above, it all depends on the quantity. Of course, if you are planning to squeeze a dozen lemons in your water, the calorie amount will be much higher than a few tablespoons and only then, it could impact your fasting state. However, if you are drinking a reasonable amount of lemon juice in your water, you will be fine. Please refer to the table above to determine the quantity best suited for you. I usually go with half a lemon squeezed in a big glass of water or a few slices of lemon in my water bottle to drink it throughout the day.

Beware of its acidity

Another point worth mentioning when talking about lemon water is its acidity. This acidity can be harmful to your teeth by causing erosion, which is the loss of tooth enamel. Please note that once it’s metabolized, it actually becomes alkaline in the body with many health benefits.

To prevent this, especially if you are drinking lemon water on a regular basis, it can be useful to drink it with a straw. But please be nice to the environment and prefer reusable ones. It is also advised to rinse your mouth with water after. Also, don’t brush your teeth right away as there is still acidity in your mouth, wait for at least 30 minutes.

Level-up your lemon water

A few slices of lemon or freshly squeezed lemon juice mixed in water are all great options, but if you want a bit of diversity, adding some other ingredients can also be beneficial.

I am not talking about sweeteners whether artificial or natural (like honey or maple syrup for example) as that would definitely bring up the calorie content. The sugar will spike your insulin, which is not what we want when we are fasting.

Ginger is a great option to add. Among other benefits, ginger is anti-inflammatory, it can help fight infections and lower blood sugar. It can treat many forms of nausea and also contains 6-gingerol than may help prevent cancer. If you want more information on how to do use ginger into your lemon water, this video will definitely help you:

Another great option to mix into your water is cucumber. Cucumber is rich in potassium, which is an electrolyte that helps to keep your blood pressure at an optimal level. Alternatively, mint-flavoured water is a great source of antioxidants and vitamin A.


If you enjoy lemon water and want to drink it during your fasting period, go ahead. It won’t break your fast and the health benefits related to drinking more water mixed with healthy ingredients are worth it.

Disclaimer: The information we provide at is not intended to replace a consultation with a qualified medical professional. By interacting with this site, you agree to our disclaimer. Read more.

Mel H.

Mel is the founder of and has always been passionate about health and wellness. When she realized several years ago the importance of food as information for the body and not just as fuel, she started her journey of learning everything she could about the subject. That is how she discovered the power of intermittent fasting. Mel loves sharing her knowledge and experience with our readers. Her approach to sharing valuable information is based on scientific facts, data-based insights, and unbiased results. Mel is a Certified Functional Medicine Health Coach and now focuses on supporting moms, helping them overcome stress and overwhelm.

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