Fasting refers to a designated period of abstaining from eating for religious, health, or other reasons.

When fasting, hydration is particularly important due to electrolyte shifts in your body.

While water is the gold standard when it comes to staying hydrated, some people prefer alternatives like lemon water. That said, you may wonder whether lemon water can break a fast.

Although lemon water is generally safe to drink during a fast, this guidance may depend on whether it contains any added ingredients, as well as the purpose of your fast.

This article covers the details of whether lemon water breaks your fast.

a pitcher of lemon water, glasses of water with lemon slicesShare on Pinterest
Photography by Aya Brackett

Lemon water contains minimal calories and nutrients. A 16-ounce (470-mL) glass provides (1):

  • Calories: 9
  • Carbs: 3 grams
  • Sugar: 1 gram
  • Fiber: 1 gram
  • Protein: 0 grams
  • Fat: 0 grams

Lemon water hardly has any measurable nutritional value, making it nearly calorie-free.

In strict terms, consuming any number of calories will break a fast. That said, human metabolism is complex and doesn’t operate like an on-and-off switch (2).

In reality, drinking plain lemon water, which contains minimal calories, is unlikely to affect your fast.

In fact, a large study in 1,422 fasting individuals permitted herbal tea with honey and freshly squeezed fruit or vegetable juice. The participants maintained ketosis — a common indicator of a fasting state — while consuming these beverages (3).

That said, if you add calorie-containing ingredients like sugar to lemon water, it will kick you out of your fast.

Reasons for fasting

When deciding whether to drink lemon water, consider the reason for your fast.

If you’re fasting for weight loss, your allowance for small numbers of calories throughout the day is fairly high.

You should still achieve sizable weight loss even while consuming very few calories during a fasting period. In fact, some fasting diets allow up to 800 calories per day (4, 5).

Yet, if you’re fasting for medical or religious purposes, the calorie tolerance may be much lower. Sometimes these fasts call for little to no calorie intake.


In general, plain lemon water is unlikely to break your fast, though you should be sure not to add sugar.

There are multiple methods of fasting, each of which has certain protocols. The type of fast may determine whether lemon water is permitted.

Intermittent fasting

Intermittent fasting is a popular method in which you cycle between periods of eating and fasting. This approach is most often utilized to promote weight loss.

Several types of intermittent fasting exist, though they’re all meant to reduce your daily or weekly calorie intake.

Several studies suggest that this eating pattern may promote weight loss when followed consistently, but compared with traditional dieting, research shows no additional weight loss benefits (6, 7).

Plain lemon water is perfectly acceptable for intermittent fasting.


Ramadan is an Islamic holy month that includes a form of intermittent fasting (8).

For a whole lunar month each year, those who observe this holiday only eat meals during nighttime hours.

This is a fairly strict pattern of fasting in which no food or drink is consumed during the day. Therefore, lemon water isn’t permitted during the fasting period.

Medical fasting

When fasting for a medical procedure, you must adhere tightly to fasting protocols to avoid any complications.

In certain situations, you may be able to drink clear liquids up to a few hours before a procedure.

It’s important to check with your healthcare professional to determine whether any foods or beverages are allowed during your fasting period.


The most common types of fasting are intermittent fasting, religious fasting (such as for the month of Ramadan), and medical fasting, each of which has varying levels of strictness.

The type of lemon water you drink — and the number of calories it contains — determines its effect on your fast.

As a rule of thumb, any beverage containing more than a handful of calories per cup (240 mL) will likely break your fast.

plain lemon waterwon’t break a fast
lemon-herb waterwon’t break a fast if it’s low calorie
artificially flavored lemon waterwon’t break a fast if free of added sugar
lemonadewill break a fast due to its sugar content
diet lemonadewon’t break a fast as long as it’s low calorie

To determine whether a packaged lemon water beverage is acceptable to drink during a fast, it’s important to read the nutrition facts panel to figure out its calorie and sugar contents.


Several types of lemon water exist. Lemon water beverages with added sugar, such as lemonade, will break your fast. It’s important to read the food label for packaged lemon water drinks to determine their calorie and sugar contents.

Fasting involves abstaining from eating for a given period for weight loss, religious, medical, or other purposes.

Considering its low calorie content, plain lemon water will not break your fast in most cases.

Yet, other lemon beverages may contain added sugar, so it’s smart to read the food label to determine the calorie content.

In addition, you should research the guidelines for your particular fasting approach.

Lastly, it’s best to check with a healthcare professional before starting a fasting protocol, especially if you have an underlying health condition.