Written by Stephen Anton PhD on October 21st, 2020

With the amount of people who start their day with coffee, and the surging popularity of intermittent fasting, many are wondering: Does coffee break a fast?

Below I’ll cover whether coffee breaks a fast and other details related to coffee and intermittent fasting.

Technically, any calories “break” a fast. However, the fasting state can be maintained when you consume very few calories.

While a zero-calorie fast maximizes results, an extremely low calorie fast still provides substantial results.

“So, can I drink coffee while fasting?”

Black coffee, yes. A cup of black coffee has less than five calories and no carbs or protein, so it practically does not affect fasting.

For all other types of coffee, the sections below provide additional information.

Autophagy improves overall cell function (improves overall health). If the goal is to enhance autophagy, you should consume very few calories during fasting.

If you are focused on autophagy, your coffee should have less than:

Autophagy is delicate. The closer to pure black coffee you can get, the better.

Ketosis improves fat loss (among other things).

If the goal is to maintain ketosis, you can consume some calories, provided they are mostly from high fat additions, such as cream, butter, or medium-chain triglycerides.

These additions will not take the body out of a ketogenic state, so you can add them to coffee without breaking ketosis.

If you are focused on ketosis, your coffee should have less than:

As you can see, ketosis is not as delicate as autophagy. Still, the less additional ingredients you consume, the more benefits you will experience.

Coffees come in many different styles. Below is a list of the 21 most popular types of coffee and whether or not they break a fast:

Overall, does coffee break a fast depends on the reason for your fast (autophagy or ketosis), and the type of coffee you consume.

In general, fasting and coffee can coexist without breaking a fast. In fact, there may be synergistic effects when fasting and coffee are combined correctly.

To help create a proper pairing, remember that black coffee is best and if you have to add ingredients, limit calories, carbs, and protein.