Does Cucumber Water Break a Fast? [Intermittent Fasting Tips]

Jan 22, 20212 min read

Updated: Jan 19, 2022

New to Intermittent Fasting and wondering if your daily cup of cucumber water will break a fast? Today, I'm sharing everything you need to know about cucumber water and Intermittent Fasting so that you can start achieving your wellness goals!

Does Cucumber Water Break a Fast?

There are two ways to approach Intermittent Fasting. One is from a true fast perspective. In this circumstance, any food or drink (other than pure water) will break a fast. Typically this is used for religious or specific therapeutic purposes. The second method is fasting mimicking. During a true fast, the storing hormone, insulin, is low. This allows the body to naturally switch into fat burning (aka lipolysis). This low insulin state can be "mimicked" by not consuming any food or drink that will spike insulin. The two macronutrients that spike insulin are protein and carbohydrates. By only consuming pure fat ingredients and liquids, this can mimic the true fast and allow the body to continue using fat as fuel. If weight loss is your goal with Intermittent Fasting, either Intermittent Fasting approach can be used.

So that brings us to our question: does cucumber water break a fast? If you are using a true fast, then adding cucumber to water will break a fast. However, if you're using the fasting mimicking approach, the answer depends on how much cucumber is in your water.

Cucumber contains carbohydrates, which is one of the macronutrients that spikes insulin. A good rule of thumb is to aim for less than 1 gram of protein and/or carbohydrates in order to stay in your "fasted" state. Using 1/8 of a medium sized cucumber brings you at less than 1g of carbohydrates. So if you're using a few slices of cucumber, you're in the clear. However, if you juice 1/4 or more of a medium sized cucumber, this is where we start to get into a little bit of murky territory. At this point, the amount of carbohydrates and protein starts to exceed that one gram rule. This still likely won't be enough to cause insulin to be secreted. However to be safe, you can opt for 1/8 or less of a cucumber in your water during your fasted state.

Pssst - wondering what type of fasting is best for your goals? Click below for my free Intermittent Fasting Schedule quiz to find out!

Will Lemon Cucumber Water Break a Fast?

When combining multiple ingredients in your water, it's important to consider the compounding effect. Roughly 1/4 of a lemon alone is safe during the fasted period, just like how 1/8 of a cucumber alone is in the clear. However, when combined, the grams of carbohydrates and protein add up as well.

In order to stay under the one gram rule, you can aim for a combination of 1/16 cucumber (or a few slices) with 1/8 lemon (or 1 slice of lemon) when combining both in your water during your fasted state.