Can you drink coffee while intermittent fasting? What other drinks are okay and not okay when doing keto and IF? I’ll tell you in this article!

RELATED: Is Coffee Bad for the Liver

In this article:

Let’s Dial-In on What You Should and Should Not Drink
Which Liquids Are Allowed with Intermittent Fasting?
What You Can Drink While Fasting: The Bottom Line

Can You Drink Coffee While Intermittent Fasting?

Let’s Dial-In on What You Should and Should Not Drink

Drink icons infographic | Can You Drink Coffee With Intermittent Fasting? And Other Acceptable Liquids

"Can I drink liquids while I am fasting?" This is one of the most common questions people have when starting off with the keto diet and intermittent fasting. It can be confusing to figure out which intermittent fasting liquids are acceptable and which are not.

Can you drink as much water as you want? Can you drink coffee while intermittent fasting? Will beverages like zero-calorie diet soda interfere with fat burning during the fasting hours? In this article, I'll answer all of those questions and more, so you can be confident knowing what to drink while fasting and what not to.

Which Liquids Are Allowed with Intermittent Fasting?

It is important to only consume low-calorie drinks during a fasted state. They should not spike insulin, stop the fat burning, or inhibit your weight loss efforts. Below is a list of beverages. These are the ones people most commonly wonder if they can include in their keto diet and intermittent fasting eating plan. I'll let you know which are okay, which you can have a little of, and which should be avoided completely if you want to see the true benefits of intermittent fasting like fat loss and better health.

1. Tea

Drinking small amounts of tea won't be a problem while intermittent fasting, but be aware that many teas do contain caffeine. Small amounts of caffeine won't break fasting, but a lot of caffeine can start to stimulate insulin levels⁽¹⁾. This gets in the way of ketosis and weight loss. So, limit caffeinated tea. Non-caffeinated herbal teas are the best choice, and you can drink as much of those as you'd like.

The final verdict: Feel free to drink plenty of non-caffeinated herbal tea. Only drink small amounts of caffeinated tea.

2. Coffee

So, can you drink coffee while intermittent fasting? Many people are afraid that if they start the keto diet and fasting protocol, they have to give up coffee completely. While I definitely don't recommend drinking coffee all day long, I think it is totally fine to drink a little bit in the morning.

One cup won't be an issue. It might help tide you over and prevent some hunger in the morning before your first meal of the day⁽²⁾. However, too much coffee isn't good. It revs up your adrenals, which activates cortisol and then spikes insulin.

Do not add sugar to your coffee because this increases blood sugar. Xylitol and erythritol are acceptable alternatives if you need a sweetener. A small amount of milk or cream is also acceptable, so add a splash if you prefer.

What about bulletproof coffee? Adding butter or fat to your coffee is okay for some people. But for others, this just adds enough calories for the coffee to act like an actual meal. For some, it kicks them out of fat burning.

The final verdict: It is okay to have a cup of coffee in the morning as long as you don’t add sugar and just use a small amount of cream and maybe a little bit of butter.

3. Water

Lemon water | Can You Drink Coffee With Intermittent Fasting? And Other Acceptable Liquids

Drinking water is not a problem while doing intermittent fasting. You want to stay hydrated so drink water as much as possible. When you are fasting, you naturally lose some water and electrolytes. So, it is important to keep your body replenished while doing this diet. Consider adding some electrolytes to your water. You might be in need of salt or potassium⁽³⁾.

You don't have to drink just straight, flat water either. Carbonation is completely fine and won't interfere with intermittent fasting at all. I love Pellegrino or other sugar-free brands. You can even add a little bit of fresh lemon for a refreshing flavor and added health benefits⁽⁴⁾. Don’t drink vitamin water as it comes with a lot of sugar.

The final verdict: Drink plenty of water and consider adding electrolytes or lemon.

4. Diet Soda

Because diet soda has little to no calories at all), some people think it might be a good option while fasting. But, diet soda is artificially sweetened, and artificial sweeteners like aspartame absolutely increase blood sugar and spike insulin levels⁽⁵⁾. This makes it a very bad idea to drink diet soda while doing the ketogenic diet and the intermittent fasting diet. They definitely slow down ketosis.

If you can find diet soda sweetened only by xylitol or stevia, those can be okay, but any sodas sweetened with aspartame are off limits (which includes most sodas labeled "diet"), even if they have zero calories.

The final verdict: Do NOT drink diet soda.

RELATED: Replace Your Coffee with Matcha Tea

5. Apple Cider Vinegar

Apple cider vinegar is like a superfood tonic. It has so many health benefits, including helping regulate blood sugar, decreasing the need for insulin, improving digestion, and helping a fatty liver ⁽⁶⁾. This makes it one of the best intermittent fasting liquids. Choose a high-quality brand. I like Bragg's organic, raw apple cider vinegar.

Combine apple cider vinegar with some water and drink it daily for all its amazing health effects. You'll find my thoughts on when to take apple cider vinegar in this video.

The final verdict: Apple cider vinegar is a very healthy fasting drink.

6. Alcohol

You might be thinking, "Well hard liquor doesn't have calories, so it should be okay, right?" Wrong!

Alcohol acts as a toxin, kills cells, causes a fatty liver, depletes vitamins, dehydrates you, and so much more. In terms of is it bad for fasting? Alcohol definitely blocks your body’s ability to burn fat, which is ultimately the goal of intermittent fasting for weight loss⁽⁷⁾. It gets in the way of weight loss. Alcohol inhibits liver function and totally knocks you out of ketosis. Do not consume it.

The final verdict: Do NOT drink alcohol.

7. Coconut Water

While it is touted as a healthy drink, coconut water is actually not very healthy. It is really high in sugar. It might be high in electrolytes, but the high sugar content is a real problem⁽⁸⁾. Any type of sugar in the diet raises insulin, and so coconut water definitely inhibits fat burning and becomes a problem when fasting. If you are looking for weight loss, ditch coconut water.

The final verdict: Do NOT drink coconut water.

8. Almond Milk

Almond milk | Can You Drink Coffee With Intermittent Fasting? And Other Acceptable Liquids

Compared to milk and milk alternatives, unsweetened almond milk actually doesn't have a lot of sugar or carbs in it. Rice milk, for example, has way more carbohydrates and sugar. Almond milk only has 1 gram of carbs and 0 grams of sugar in a cup. Don't drink too much of it, but a little bit here and there is not a problem. Just make sure you choose an unsweetened brand and check for other ingredients you might be sensitive to.

The final verdict: Unsweetened almond milk is okay in small amounts.

9. Milk

I would not recommend drinking milk while fasting. It actually has quite a lot of sugar per serving, which boosts insulin and stops fat burning. However, a little splash of grass-fed, organic milk in your coffee isn’t a problem.

The final verdict: Don't drink a lot of milk. A splash in your morning coffee is okay.

What You Can Drink While Fasting: The Bottom Line

While following a low-carb keto diet and doing intermittent fasting with a proper workout routine, the goal is to go into the fat burning mode. This helps get your body healthy, lose weight, and make you feel great. But, don't worry. While you are fasting, you don't have to starve your body of anything and everything. There are many acceptable low-calorie beverages to drink during your fasting time. Having a little something to drink can help stave off hunger pangs and can be satisfying between meals.

Let's review the acceptable liquids for intermittent fasting.

Totally okay to drink:

Water (with electrolytes, carbonated, with lemon, etc.)
Apple cider vinegar
Herbal teas

Not a problem in small amounts:

Coffee
Caffeinated tea
Unsweetened almond milk
Grass-fed, organic milk in your coffee

Off limits:

Diet soda
Alcohol
Coconut water

If you’re a coffee lover, the question “can you drink coffee while intermittent fasting?” is surely one of the first things you need an answer to. Hopefully, this guide answers your question and sheds more light on the matter to make sure your intermittent fasting works.