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Does Celsius Break a Fast? Unveiling the Truth Behind Fasting Myths

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What is Celsius? | Does Celsius break a fast? | Is Celsius keto friendly? | Why it’s important to keep a fasting window

There are plenty of energy drinks on the market today, but one of the most popular energy drinks recently has been Celsius. Celsius is a low-calorie, zero-sugar energy drink advertised as a fitness drink to speed up metabolism and provide energy. With athletes like Jake Paul endorsing Celsius, it has risen to the top of the energy drink market. 

With so many new foods and drinks available today, it can be challenging to figure out if something will break your fasting window while intermittent fasting. Since the basis of intermittent fasting depends on keeping a fasting window and an eating window, it’s important to know which foods will or won’t break a fast. 

In this article, we will answer questions like can you drink celsius while fasting? How many calories in celsius?, and is celsius keto friendly?. We will also take a look at what’s in Celsius and why it’s important to keep your fasting window. 

Does Celsius Break a Fast

What is Celsius? 

Celsius is a popular energy drink that made its way onto the market around 2004. Marketed as a healthier energy drink, Celsius is used for better performance in the gym and on the field. 

There are several different products that Celsius offers including Celsius Heat, the original Celsius, and Celsius Essentials. They also have a powder “on-the-go” drink option.The original celsius comes in 23 different flavors such as sparkling strawberry lemonade and sparkling mango passion fruit. 

According to the Celsius website, their product contains the following key ingredients: 

  • Green Tea Extract
  • Guarana Seed Extract
  • Ginger Root
  • Vitamin B
  • Vitamin C
  • Chromium

Additionally, their products are kosher, vegan, sugar free, and soy free. Since Celsius is an energy drink, it does contain a large amount of caffeine (about 200 mg per can). The FDA recommends no more than 400 mg per day of caffeine for healthy adults. 

This amount is generally not associated with negative side effects, however some people metabolize caffeine differently and are more sensitive to its effects. 

So, if you are asking yourself, “how many celsius can I drink in a day?”, it’s best to drink no more than 2 cans for the average, healthy person. This would be a total of 400 mg of caffeine which is the FDA’s recommended limit for daily caffeine. It’s important to talk to your healthcare provider if you are unsure how much caffeine is safe for you to drink. 

Similarly, some people feel the effects of caffeine quicker than others. How long does Celsius take to kick in would be dependent on the individual, but typically caffeine takes about 30 to 60 minutes to take effect. Sometimes the effects of caffeine can be felt up to 5 hours after it was first consumed, so it’s best to limit caffeine a few hours before you plan to go to bed. 

Does Celsius Break a Fast

Does Celsius break a fast? 

So let’s answer the main question here, does Celsius break a fast? The answer for most people who practice intermittent fasting is no, original Celsius does not break a fast

Anything with a significant amount of calories will break a fast, so how many calories in Celsius? With only 10-15 calories per can of Celsius, it doesn’t contain a significant amount of calories to raise insulin levels during a fast. It also doesn’t contain any carbohydrates or protein which, even in small amounts, can raise insulin levels. 

Two ingredients contained in Celsius, green tea and ginger, are widely used during fasting windows and would not break a fast. Vitamins by themselves are also calorie-free and would not break a fast. It is worth noting that Celsius does contain sucralose which some studies have suggested could change glucose, insulin, and GLP-1 levels. 

Intermittent fasting can be practiced for a variety of reasons. No matter how long your fasting window is, it’s important to maintain little to no food intake during that time. Some choose to do dry intermittent fasting where no food or water is allowed during fasting windows. In this case, Celsius would break their fast. 

However, for most people who are doing intermittent fasting to try to lose weight or for overall health, Celsius would not break their fast. This is similar to how black coffee does not break a fast. Herbal tea and zero-calorie drinks are allowed during a fasting window as well. (Read What can you drink during intermittent fasting? For more on this) 

It’s important to note that drinking a significant amount of caffeine while fasting might make you feel jittery and dizzy. The average cup of coffee contains about 120mg of caffeine while Celsius contains 200mg. If you are sensitive to caffeine, you may want to wait and drink Celsius after having some food. 

Timing is important when it comes to intermittent fasting. Since intermittent fasting is a schedule of when to eat, it can be tailored to your specific schedule and lifestyle. 

If you typically exercise in the morning, for example, then you may want to have your eating window start sometime around your exercise time. Most people choose to have the longest portion of their fasting window while they are sleeping. 

There are many types of intermittent fasting schedules ranging from fasting for 16 hours and eating for 8 hours to fasting for 20 hours and eating for 4 hours. Your intermittent fasting schedule would depend on a variety of factors. 

One important reason to consider when choosing an intermittent fasting type is why you are doing intermittent fasting in the first place. Is it for weight loss? Or more energy? It’s essential to consider this as you are choosing the schedule that is right for you. 

Is Celsius keto friendly? 

Another reason that intermittent fasting is so popular is because it works so well with other diets. Since intermittent fasting doesn’t restrict any types of foods, it is compatible with diets like paleo, vegan, and keto

The keto diet is a low-carbohydrate, high-fat, and moderate protein diet. The idea is to keep carbohydrate intake extremely low so your body goes into ketosis to retrieve stored fat for energy. Foods that contain high amounts of carbohydrates (like pastas, breads, cookies, and crackers) are not allowed. You will want to be sure and read ingredient labels while following a keto diet to ensure there is little to no carbohydrates in the foods you eat. 

Drinks can be a little trickier on a keto diet. There are plenty of keto-friendly drinks such as apple cider vinegar, green tea, and coffee. Depending on the type of keto diet you choose, artificial sweeteners may or may not be allowed. Celsius does contain sucralose (an artificial sweetener), but doesn’t contain any net carbohydrates so it is keto friendly for many on the keto diet. 

Intermittent Fasting and Loose Skin

Why it’s important to keep a fasting window

Even though it can be difficult to stay away from food for 14, 16, 18, or even 20 hours, it’s important to maintain your fasting window while intermittent fasting. Here are a few benefits of keeping your fasting window: 

Lower insulin levels

Intermittent fasting works because during the fasting period, the body has a chance to undergo cellular repair and lower insulin levels. Lower insulin levels can have beneficial effects on blood sugar control which reduces the risk of insulin resistance. 

When insulin levels are consistently raised due to high carb foods or added sugars, this can decrease cell sensitivity to insulin leading to insulin resistance. Reducing the risk of insulin resistance also decreases the risk for certain health conditions like type 2 diabetes. 


During a fasting window, a process called autophagy can occur. This is a process where cells remove other damaged cells. 

Autophagy is important to keep cells and your body healthy. Consistently keeping regular fasting hours ensures this important cellular process can do its job. 

Helps with weight loss

It is also beneficial to keep your fasting windows if you are intermittent fasting for weight loss. When you consistently maintain your fasting window, then you aren’t snacking late at night. This means you are likely taking in less calories overall which may lead to weight loss. 

This is why intermittent fasting works for weight loss, even if you don’t regularly count calories.

So, as you can see, it’s important to maintain a fasting window while intermittent fasting. There are many foods and drinks that can break a fast so you should consider which ones will break your fast. 

As a general rule of thumb, any foods or drinks that contain a significant amount of calories will break your fast. The specific calorie amount can be different for different types of intermittent fasting but it’s generally in the range of 15-25 calories will break a fast. 

Coming in at 10 calories, Celsius energy drink isn’t likely to break a fast. Celsius does contain quite a bit of caffeine, so this is something to consider. Some people may experience the side effects of too much caffeine on an empty stomach. 

With green tea extract, B vitamins, and vitamin C, Celsius can be a good option for someone looking for an energy drink that won’t break a fast.

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