Part of our Mushroom Coffee guide library.
Short answer: Strictly speaking, most mushroom coffee does break a fast, because it has some calories. One serving of NeuroCoffee has 25 calories, while plain black coffee has only about 2 calories per cup. Whether that matters depends on your fasting rules: if your fast allows no calories at all, drink mushroom coffee during your eating window instead. Adding milk, creamer or sugar adds more calories either way. No study has tested mushroom coffee during fasting.
Many people who fast drink black coffee to get through the morning, so it is natural to ask whether a mushroom coffee is just as fine. Here is how many calories mushroom coffee has, how that compares with black coffee, and how to fit it into your fasting schedule.
What you'll learn
- How many calories mushroom coffee has compared with black coffee
- What "breaking a fast" means in fasting studies
- Whether additions such as MCT oil, milk or creamer change the answer
- How to fit mushroom coffee into a fasting schedule
Does mushroom coffee have calories?
Yes, a few. Mushroom coffee blends contain coffee plus mushroom extracts and sometimes other ingredients, and those add calories that black coffee does not have:
| Drink | Serving | Calories |
|---|---|---|
| Black coffee, brewed | 1 cup (8 fl oz, 237 g) | About 2 (USDA FoodData Central: 1 calorie per 100 g) |
| NeuroCoffee (mushroom coffee) | 2 tbsp (6 g) | 25 (Product Facts) |
| NeuroMatcha (mushroom matcha) | 2 tbsp (6 g) | 20 (Product Facts) |
| Any blend with milk, creamer or sugar | Varies | More, depending on what you add |
Other mushroom coffee brands vary, so check the calories per serving on the label.
What counts as breaking a fast?
It depends on the rules you follow. In a well-known U.S. trial of 16:8 time-restricted eating, participants were told to eat only between noon and 8 p.m. and to completely abstain from caloric intake the rest of the time (Lowe et al., 2020). By that kind of rule, anything with calories, including a mushroom coffee, breaks the fast.
Some people follow looser rules and allow a small number of calories during their fast. There is no research showing exactly how many calories are "too many," and none on mushroom coffee specifically, so if you are unsure, follow the strictest version of your plan.
What about MCT oil, milk and creamer?
- MCT oil and coconut milk powder are fats, and fats have calories. NeuroMatcha contains both (Product Facts), which is part of why it has 20 calories per serving.
- Milk, creamer and sugar add more calories than the coffee itself, so a mushroom coffee latte breaks a strict fast.
- Sweeteners vary; check the label of anything you add.
How to fit mushroom coffee into a fasting schedule
- Strict fast (no calories): drink water, black coffee or plain tea while fasting, and have mushroom coffee with your first meal.
- Looser fast: if your plan allows a small number of calories, a plain serving of mushroom coffee without milk or sugar adds only a little. Decide in advance, so you stay consistent.
- Watch your stomach. Caffeine increases the release of stomach acid, which can lead to an upset stomach or heartburn (MedlinePlus), and that can feel worse on an empty stomach. See when to drink mushroom coffee for more on drinking it before food.
- Mind the timing. If your eating window runs late, remember that mushroom coffee still contains caffeine; see does mushroom coffee have caffeine?
Who should be careful with fasting
Talk to your health care provider before you start fasting if you have diabetes or take medicines that lower blood sugar, take other regular medication, are pregnant or breastfeeding, or have a history of an eating disorder. The same goes for adding caffeine on an empty stomach if you have GERD or ulcers (MedlinePlus).
Common myths (quick reality check)
Myth: Mushroom coffee has zero calories, like black coffee. Reality: Most blends have a few. NeuroCoffee has 25 calories per serving, compared with about 2 in a cup of black coffee.
Myth: The mushrooms are what breaks the fast. Reality: It is the total calories that matter for a strict fast, whether they come from mushroom extracts, MCT oil, milk or sugar.
Myth: A few calories never matter. Reality: It depends on your rules. Many fasting plans, including those used in trials, allow no calories during the fasting window.
Frequently asked questions (FAQ)
Does mushroom coffee break a fast?
Strictly, yes, because most mushroom coffee has a few calories. NeuroCoffee has 25 per serving, compared with about 2 in a cup of black coffee. If your fast allows no calories, have it with your first meal.
How many calories are in mushroom coffee?
It depends on the brand. One serving of NeuroCoffee (2 tablespoons) has 25 calories and NeuroMatcha has 20. Milk, creamer or sugar add more.
Does black coffee break a fast?
Black coffee has about 2 calories per cup, so many fasting plans allow it. A strict zero-calorie fast would technically exclude it.
Can I drink mushroom coffee during intermittent fasting?
Yes, during your eating window. During the fasting window, it depends on whether your plan allows a small number of calories.
Does MCT oil break a fast?
MCT oil is a fat and has calories, so it breaks a strict fast. Some mushroom blends, such as NeuroMatcha, contain MCT oil.
Is it OK to drink mushroom coffee on an empty stomach?
Many people do, but caffeine increases stomach acid, which can cause an upset stomach or heartburn. If that happens, have it with food.
Related guides
- When to drink mushroom coffee
- Does mushroom coffee have caffeine?
- Does mushroom coffee make you poop?
- Mushroom coffee vs regular coffee
- Mushroom coffee side effects
Disclaimer and when to seek help
This article is for general education and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure, or prevent any disease. Talk to your health care provider before fasting if you have diabetes or another medical condition, take medication, are pregnant or breastfeeding, or have a history of an eating disorder.
References
- U.S. Department of Agriculture. "Beverages, coffee, brewed, prepared with tap water" (FDC ID 171890). FoodData Central, SR Legacy.
- Lowe DA, et al. "Effects of time-restricted eating on weight loss and other metabolic parameters in women and men with overweight and obesity: the TREAT randomized clinical trial." JAMA Internal Medicine, 2020;180(11):1491-1499. doi:10.1001/jamainternmed.2020.4153
- MedlinePlus (U.S. National Library of Medicine). "Caffeine".
- OurJrney. Product Facts: caffeine, serving size and ingredients.
