Does lemon water break a fast?

A slice of lemon or a small squeeze in water has almost no calories and is generally considered fine. Larger amounts of juice add sugar and can end the fast.

Does sparkling water break a fast?

No, as long as it is plain or naturally flavoured with no sugar or calories.

Can you drink too much water while fasting?

It is possible but uncommon. Drink steadily through the day instead of large amounts at once, and let thirst guide you.

Does water break a fast?

The short answer is no, and you should be drinking more of it, not less.

Short answer

No. Plain water does not break a fast. It has no calories and does not affect blood sugar or insulin. Still and sparkling water are both fine during intermittent fasting, and staying hydrated makes fasting easier.

Why water does not break a fast

A fast is broken by calories. Water has none, so your body stays in the fasted state however much you drink. This applies to intermittent fasting for health or weight. Religious fasts and fasting before surgery or some medical tests have their own rules, so follow those instructions instead.

Lemon water, sparkling water and the rest

Sparkling water: fine, as long as it is unsweetened.
Water with a slice of lemon: a slice or a squeeze adds a negligible amount and is generally accepted. A glass of lemon juice is not.
Electrolytes: unsweetened, zero-calorie electrolytes are fine. Sweetened sports drinks are not.
Flavoured water: check the label. If it has sugar or calories, it ends the fast.
Zero-calorie sweetened drinks: no calories, but opinions differ. If you want a clean fast, leave them for your eating window.

For coffee, tea and everything else, see what you can drink while fasting.

Why drinking water helps you fast

Thirst is easy to mistake for hunger. A glass of water often settles it.
You normally get some of your water from food. When you are not eating, you need to drink it.
Headaches and tiredness during a fast are often signs you need more fluid.

Track water during your fast with Bide

Bide has a water tracker on the same screen as the fasting timer, so the two habits support each other.

Find the water card under the timer
It shows how much you have had today against your daily goal.
Add a drink in one tap
Use +250 ml or +500 ml, or enter your own amount. Glass, cup, mug and bottle presets are there too.
Check your day
The water log lists every entry by time. Remove one if you tapped by mistake.

Coming soonApp Store

Coming soonGoogle Play

Free trial. No account needed.

Common questions

A slice of lemon or a small squeeze in water has almost no calories and is generally considered fine. Larger amounts of juice add sugar and can end the fast.

Sources

The studies and health guidance this guide draws on.

Water, drinks and hydrationNHS
Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and SulfateNational Academies Press, 2005
Intermittent Fasting and Human Metabolic HealthJournal of the Academy of Nutrition and Dietetics, 2015

This guide is general information, not medical advice. Talk to a doctor before fasting if you are pregnant or breastfeeding, under 18, have a health condition or take medication.

Short answer

Why water does not break a fast

Lemon water, sparkling water and the rest

Why drinking water helps you fast

Track water during your fast with Bide

Find the water card under the timer

Add a drink in one tap

Check your day

Common questions

Sources

Keep reading