You already know that you can’t eat during the fasting part of your intermittent fasting schedule, but one of the most common questions from IF newcomers are “What can you drinkduring intermittent fasting?” and “Will it break my fast if I drink ______?”
In this post, we’ll explore what’s okay to drink during a fast, and what it’s best to avoid.
The Logic of Fasting
Before jumping into what beverages are okay to have during a fast, and which are not, let’s talk about what we’re trying to accomplish with a fast in the first place. That will help us understand why certain things are okay, and others we want to avoid.
Much of the benefit of intermittent fasting comes from the prolonged lowering of blood glucose levels. Blood glucose levels spike after we eat (and can vary enormously based on what we eat), and then gradually drop over the course of several hours. After many hours of not eating, blood glucose and insulin levels drop far enough that the body eventually begins to look for other sources of energy like protein or fat.
So the simple goal is to avoid raising blood glucose level, which pretty much any caloric intake will do. But it also means we can still enjoy some of our favorite beverages, just being sure not to introduce any calories by adding sweeteners or creamers.
Beverages to Enjoy
Since we’re trying to avoid spiking out glucose levels, there are several calorie-free beverages we can enjoy without breaking a fast:
✅ Black Coffee
✅ Unsweetened Tea
Both coffee and tea without sweeteners or creamers may be difficult to get used to for some fasters, so I’d encourage you to try a variety of different coffees and tea to find one that works for you without any modifications. With coffee, for example, you could try out a low acidic variet which may be more palatable without any creamer. For tea, you can try a green or white tea which both tend to have lower tannin levels than black tea, making them less “harsh” to drink.
Beverages to Avoid
Again, the rule is to avoid any kind of caloric intake, so that means most beverages aside from the above are not allowed, including the following:
❌ Soda or juice
❌ Coffee or tea with creamers or sweeteners
Again, any food or drink with caloric value will definitely break a fast, so definitely avoid these choices.
Beverages to Be Wary Of
There’s one category which is a little more complicated, and you’ll need to make up your own mind:
⁉️ Drinks sweetened with artificial sweeteners
Artificial sweeteners are a tricky topic in intermittent fasting. Some people (including myself) avoid them entirely, but others point out that there are some calorie-free options which won’t break a fast. Even though some artificial sweeteners are completely calorie free and generally don’t have an impact on blood glucose levels, there is some conflicting research on the topic and indications artificial sweeteners may have other undesirable impacts on gut bacteria, etc. There is also some evidence to suggest that artificial sweeteners are not good for weight loss for reasons entirely unrelated to blood sugar levels.
If you do choose to use artificial sweeteners, do a bit of further research and choose one that’s calorie-free and safe for fasting. If you have any doubt, I’d opt to avoid artificial sweeteners as part of a fast.
Beverages to Try
There are a couple of beverages you might not consider drinking otherwise which are actually excellent choices as part of a fast:
✅ Water with a pinch of salt
✅ Water with lemon or lime juice
✅ Sparkling water
All of these alternatives are okay to consume without breaking a fast and may be more palatable than just plain water all of the time. The “pinch of salt” in particular may be helpful to give you some of the minerals you’d be missing out on by not eating. If you go down this path, feel free to try different varieties of salt–there really are big differences?
Recap: Calories Bad, Calorie-Free Options Good
In the end, it’s quite simple: consuming food or drink with any calories will break your fast, but there are plenty of good-tasting, calorie-free beverages to choose from. As for artificial sweeteners, it’s simplest to avoid them, but probably okay if you’re careful about which ones you consume.
And don’t be afraid to try new things! There are so many varieties for coffees and teas. Even if you think you don’t like black coffee or unsweetened teas, chances are you can find something you do like if you try some different options.