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    Can You Drink Coke Zero While Intermittent Fasting?

    When it comes to intermittent fasting, you are often told that you cannot eat or drink anything with calories while you are in your fasting period. However, drinks that do not have any calories are often allowed. This usually includes black coffee, tea and water. Usually, diet sodas such as Coke Zero are not mentioned. If you are wondering if you can drink Coke Zero while fasting then it really depends on what your fasting goals are. 

    What is Intermittent Fasting?

    Intermittent fasting is an eating plan that rotates from an eating period to a fasting period. It is often a popular diet choice for those who are looking to lose weight. Instead of focusing on what you can or cannot eat, intermittent fasting is only about when you eat. 

    There are many different methods to do intermittent fasting, the most popular one is usually the 16/8 intermittent fasting. This is where you fast for 16 hours and eat for the remaining 8 hours of the day. This method is great for beginners because you most likely only need to skip breakfast or dinner. 

    When you stop eating, your body eventually runs out of the sugar stored in your body and will turn to burning fat to help keep your body running. This generally starts at around 12 hours into your fast and maximizes the fat burning at 16 hours. 

    When you are in your eating period, you can eat anything you want. You are not limited to eating certain foods or clean eating like in some diets. However, it is suggested that you do try to keep within your calorie limit as you will gain weight if you are eating more than your body is burning in a day. You will not lose weight or become healthier if you fill your eating periods with high calorie unhealthy foods.

    When you are fasting you are not suppose to consume any calories at all. This means you should not eat anything and stick to drinking black coffee, straight tea and water. Any food and drinks that contain any calories will technically break your fast.  

    Coke Zero Sugar will be changing its flavor – KIRO 7 News Seattle

    Can You Drink Coke Zero While Intermittent Fasting?

    People usually assume that because a drink has zero calories, it should not break a fast, right? However, that is not true. Calories are not the only thing that will break a fast. The ingredients in your diet sodas have the potential to break your fast too. However, depending on your fasting goal, it might be possible for you to drink Coke Zero while you are doing your intermittent fast. 

    Coke Zero uses artificial sweeteners to sweeten the Coke beverage without adding any calories. It does to provide any calories and is not a significant source of nutrition. Because it uses sweeteners, it does not contain any sugar in the drink. Coke Zero is sweetened using a blend of aspartame and acesulfame potassium (Ace-K) to help sweeten the drink without adding any calories. 


    Aspartame is a popular sweetener for many diet sodas. It has been used for decades and it is about 200 times sweeter than sugar, therefore only a small amount is necessary to match the sweetness that is provided by sugar. Aspartame is actually made up of two amino acids – aspartic acid and phenylalanine. When you consume it, the aspartame is broken down into the amino acids and used in metabolism and protein synthesis. 

    Acesulfame Potassium

    Acesulfame Potassium

    Acesulfame potassium is another sweetener that is calorie free. Because it provides a slight bitter after taste, it is often blended with other sweeteners such as aspartame in food and drinks. Acetoacetic acid and potassium is combined together to form the stable acesulfame potassium. 

    Currently there still isn’t enough studies to prove or disprove that sweeteners such as aspartame and acesulfame potassium can provoke an insulin reaction. If there is no calories and insulin response to the sweeteners, it might be possible that your fast is still going. If you are fasting for weight loss, it might be possible for you to drink Coke Zero. 

    Because we cannot be 100% certain whether sweeteners can stimulate insulin release, it is probably ideal to skip Coke Zero if you want a true fast. However, If you feel that it is difficult to hold off on Coke Zero while you are fasting or it might be beneficial to helping you maintain your fast, you can try fasting with Coke Zero to see if you get good results. If it works out fine and you are achieving weight loss, then feel free to continue. 

    If you are fasting for gut rest then you will have to stop drinking Coke Zero. Some people fast to help protect their gut microbiome. However, the sweeteners in Coke Zero are digested and therefore it will stimulates your gut. Artificial sweeteners may even change the balance of the bacteria in your gut. In fact, artificial sweeteners can turn your healthy bacteria in your gut microbiome into harmful microbes and might even cause harmful health effects to you. 

    Since aspartame is digested into amino acids, it will break your fast if you are fasting for autophagy. Amino acids are protein molecules that will stimulate your mTOR pathway. The mTOR is responsible for cell growth and reproduction. This means that when mTOR is stimulated, autophagy will turn off. Therefore, drinking Coke Zero will lead to a break in your fast and preventing autophagy from happening in your body. 


    When in doubt, it is best to avoid it. It may or may not have an impact on your fast, it really depends on what your fasting goals are. If you really cannot avoid drinking diet sodas such as Coke Zero while you are in your fasting period, then give it a try. See how you feel during your fast and take note on the effect it has on your fast.  

    2 thoughts on “Can You Drink Coke Zero While Intermittent Fasting?

    1. Informative post. Thank you for mentioning that artificial sweeteners can damage the gut microbiome and cause harmful health effects. I have recently learned about this and feel that it speaks volumes to the fact that people should avoid foods containing artificial ingredients.

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