Can You Drink Coffee While Intermittent Fasting for Weight Loss?

Does a cup of coffee break a fasted state?

Keep reading to learn if caffeine while fasting will help or hurt your fasting window when it comes to intermittent fasting for weight loss.

Before we talk about whether caffeine helps or hurts your fast, I wanted to let you know this blog may contain affiliate links where I receive a small commission. I also link to the same resources that helped me lose 100 pounds with a low carb and intermittent fasting lifestyle.

Can You Drink Coffee While Intermittent Fasting for Weight Loss?

While the answer to this question isn’t cut and dry, I’ve got good news for all of the coffee lovers. In most cases coffee consumption during intermittent fasting will not break a fast. It can even be a good idea since coffee can increase the benefits of intermittent fasting in some people.

The benefits of fasting with a cup of joe might include:

Improved brain function
Reduced inflammation
Reduced blood sugar
May reduce hunger pangs during the fasting state

When Does Coffee Break Your Fast?

There are two big things things in general that will break a fast:

Anything with calories
Anything with a sweet taste

While not all fasting experts agree on this, the short answer is if you’re having either of these things while fasting for weight loss, you’re making your fasted time harder on yourself.

This includes adding artificial sweeteners, heavy cream, and even that seemingly harmless splash of milk.

More on what you should add to your cup of coffee in a minute…

But Doesn’t Coffee Have Calories?

While coffee can’t claim zero calories, when you drink it black it comes pretty close. According to Cronometer, my favorite macro tracking app, black coffee contains 1.8 calories per cup. That’s typically not enough of a caloric intake to kick your body out of a fasted state.

This is mostly true since coffee has a bitter taste. The bitter taste makes it safe for most people to consume during the fasting period.

What About Adding Artificial Sweeteners to Coffee?

This is where opinions start to vary in the fasting community. Many assume since most keto-friendly sweeteners are low calorie, they’re OK to add to coffee while you patiently wait for your first meal.

Consuming zero-calorie beverages, like artificially sweetened coffee, leads to low insulin sensitivity. While you may think this is a good thing, it makes you more insulin resistant. The more insulin resistance you have, the harder it will be to lose weight with a keto diet.

When you consume anything sweet during fasting hours, insulin is triggered. Your body expects a sweet tasting food to follow soon after. This causes insulin to rise. Insulin can remain spiked longer when you don’t give your body what it expects.

In the case of added sweeteners, the number of calories is really null and void. It’s that sweet taste that tricks your body into believing food is on the way. This includes sweeteners that claim they are natural, as well as sugar alcohols.

Sweeteners can also cause small changes to your gut microbiome overtime, which can interfere with long term gut health.

The bottom line is while I don’t believe consuming too many sweetened foods helps anytime of day, I’d definitely avoid them while trying to speed up weight loss on an empty stomach.

Be Wary of Coffee Shop Coffee:

Stopping at Starbucks may be the highlight of your day. If it is, I won’t tell you to stay away. I do want to add this quick warning – big enough to have it’s own bolded section.

You have to be careful when it comes to the drinks you order from coffee shops. Many chains add sweetener right to the coffee you order without even asking your permission! This is more prevalent when it comes to the iced coffee varieties.

I always make sure to explicitly say no sweetener when I order coffee. You may need to do this even with drinks that aren’t supposed to have added sweeteners in the first place. Some baristas are new and get a little sweetener-happy when handing out your morning coffee.

Does Bulletproof Coffee Break My Fast?

Before I answer this question, let me explain what bulletproof coffee is. (Also known as BPC).

Many in the keto community add healthy fats like coconut oil, MCT oil, and grass-fed butter to coffee to increase fat loss on a ketogenic diet.

While this is a whole other controversial topic in itself since some say bulletproof coffee has too much fat, BPC can be one of the best ways to sneak healthy fats into a keto meal plan. We teach this tactic to Keto Challengers since this is important if you’re not able to eat enough fat to trigger ketosis.

Far too many women come into the challenge because they’re stuck in a weight loss stall. Fasting too much to get enough fat to trigger ketosis is sometimes the culprit. Adding an intermittent fasting routine before you are fat adapted is another big problem.

This is why bulletproof coffee is on the menu for some challengers. BPC doesn’t stop at just coffee either. Many people add healthy fats to green tea, herbal teas, or even bone broth to ensure a healthy fat boost throughout the day.

While I do believe BPC can have beneficial effects for some people looking to lose weight on a ketogenic diet, I recommend sticking with plain black coffee during the fasting window. Save the health benefits that come along with bulletproof coffee for your eating window.

Let’s use a common 16:8 intermittent fasting approach as an example:

This is an intermittent fasting schedule where you remain in a fasted state for 16 hours. You only consume calories in an 8-hour window each day. In case you’re not familiar with a 16:8 fast, the time you sleep does count towards time in a fasted state.

To achieve a 16 hour fast, let’s say you stop eating all food after dinner at 6 pm. You can keep a clean fast going by drinking plain water until you go to bed. Do not drink coffee that late in the evening since that will screw up sleep. Not getting quality sleep leads to entirely different weight loss problems.

In order to receive the best effects of intermittent fasting, continue to drink only plain water and plain black coffee until it’s time to open your feeding window at 10 am.

Just like that, you completed an easy 16:8 fast where you were able to keep both insulin levels and blood glucose levels low.

If following a 16:8 fast doesn’t come just like that to you, watch this video on how to easily combine an intermittent fasting plan with keto for better weight loss results.

Regular Coffee or Decaffeinated Coffee – Which is Better for Fasting?

The effects of coffee during your fasting window really depends on the state of your hormones. While coffee in general can be anti-inflammatory, drinking too much caffeine won’t benefit your metabolic health if you display signs of adrenal dysfunction.

Some signs of adrenal fatigue include:

Brain fog
Cravings for sweet and salty foods
Poor stress response and mood regulation
Feeling fatigue throughout the day, especially upon waking

If you display these symptoms while following a keto and intermittent fasting lifestyle, adding even more stress to the equation with too much caffeine intake is bad news bears.

Cutting most carbs out of your diet with a ketogenic diet is a stress to your body. This is especially true if your digestive system isn’t up to par when adding more fat and protein to your meal plan.

Going long periods without food, aka intermittent fasting, is also a stress to your body.

While these stressors can be an effective way to burn fat for many, if you also display signs of adrenal fatigue and then add too much coffee on top of this, all three of these combined can create levels of stress hormones that are out of control. AKA – you won’t lose weight. And you’ll feel pretty bad on top of it!

How can you reap the benefits of coffee and intermittent fasting if you’re stressed out?

If you do have any signs of adrenal dysfunction, I would never recommend what most people consider a safe level of caffeine intake. Most say it’s OK to have up to four conventional cups of coffee each day. If your body is already stressed out, drinking that much caffeine isn’t doing you any favors.

One obvious switch is to swap the real thing out for a decaffeinated version. This is your best bet since you’ll still get all of the polyphenols that lead to the anti-inflammatory benefits of coffee.

Another tactic to try is to reduce coffee intake when it comes to the caffeinated variety to only one cup in the morning. If you still want coffee the rest of the day, keep the decaffeinated version flowing.

Caffeine While Fasting Recap:

To settle the big question: can you drink coffee while intermittent fasting and still lose weight?

The basic answer is yes. In some instances, drinking coffee can even help extend your fast!

But we’re talking plain black coffee here – no added sweeteners and no splash of cream. While you can add a little bit of salt to make coffee less bitter, please quit basing intermittent fasting on staying under a certain calorie count during the fasting window.

Following this outdated fasting logic hurts your long term results.

If your primary goal is fat loss, keeping a clean fast will take you much further. It takes many people a long time to come to this same conclusion. There’s hardly anyone out there who will tell you once they started following a clean fast, it was harder to lose weight.

If you’re overly stressed and experiencing signs of adrenal fatigue, caffeine in general is a bad idea. Adding more caffeine to a keto and intermittent fasting plan is a just plain awful strategy.

Love learning all of the intermittent fasting strategies that helped me lose 100 pounds? Watch this free keto masterclass to learn 3 big mistakes most keto dieters make that keep them stuck.