Is Diet Coke or Coke Zero Better For Keto?

minute read | Last update: Nov 30th2022

This article is backed by studies and reviewed by a certified dietician.

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Are you on a keto diet and wondering if the can of Diet Coke sitting in your fridge is okay for your Ketosis?

If you are, this is the right place for all your doubts!

The answer to this question is you can have Coke Zero or Diet Coke as they both have rather similar effects on your keto diet. They are low-carb beverages with close nutrient profiles, making no option better or worse than the other. The only catch is that these drinks contain unhealthy elements like aspartame, potassium benzoate, and acesulfame K, which might not be the best for your body.

To understand this better, read on ahead as we discuss the ins and outs of drinking Diet Coke on a keto diet coupled with information on the ingredients of this drink and its nutritional value.

Is Diet Coke and Coke Zero the same?

Diet Coke and Coke Zero are both beverages with zero calories and sugars and somewhat similar ingredients. They contain carbonated water, phosphoric acid, potassium benzoate, caramel color, Caffeine, and natural flavors.

The significant difference is that Coke Zero comes with two extra ingredients: potassium citrate and acesulfame potassium, whereas Diet Coke consists of Citric acid.

Taste-wise, most people prefer Coke Zero since it tastes just like Classic Coca-Cola. On the other hand, Diet Coke has a light taste and blend of flavors new to your palette. Plus, Coke Zero consists of limited Caffeine content compared to Diet Coke.

Ketosis with Diet Coke

When you are on a keto diet, your body’s metabolism is altered into a state called Ketosis. What does this ‘ketosis’ mean, though? The body doesn’t burn carbs but fats for energy during this state. Ketosis is achieved by maintaining low carbohydrate levels in the diet.

A 12-ounce can of the classic sugar-sweetened Coca-Cola has about 39 grams of carbs, while Diet Coke or Coke Zero has zero. So, it becomes a fit for your keto diet! With a low carb count (between 20 to 50 grams in a day) through Coke Zero, you will be able to maintain the ketosis state.

While Diet Coke is essentially keto-complaint, a negative is that it leads you to crave even more. The artificially sweetened drink aims to trick the body into believing the carbs have all been taken in. But, sooner or later, your body will realize it is not the case and lead you to overeat.

Coke Zero Nutritional Information

You can find four typical flavors in the case of Coke Zero – Original, Cherry, Vanilla, and Orange Vanilla. The regular size for these cans should be about 12 Fl oz. Technically speaking, Coke Zero has zero fats, zero carbs along with 0 protein.

Coke Zero also contains about 40 mg of Sodium in the Original, Vanilla, and Cherry flavors while 35 mg of Sodium in the Orange Vanilla flavor. There will be some limited amounts of potassium in the mix. Additionally, you will also find Caffeine in the drink constituents.

Artificial Sweetener in Your Diet Coke

The flavor in your Diet Coke or Coke Zero is obtained through a combination of artificial sweeteners and flavorings. Such elements substitute table sugar and bring a sweet taste to the product that the buyers love.

These artificial sweeteners are none other than acesulfame potassium (Ace-K) and aspartame. We will talk more about these in the coming section.

Aspartame and Acesulfame Potassium in Diet Coke

Aspartame and Acesulfame Potassium in Coke Zero build a sweet taste with zero calories and zero sugars in the bottles. Acesulfame potassium is a calorie-free sweetener that doesn’t increase the sugar levels in the body. On the contrary, Diet Coke only contains aspartame as the sweetening agent.

Keto-Friendliness of Aspartame and Acesulfame potassium

Additives like Aspartame and Acesulfame potassium do not contribute to the calorific content of the drink but are related to many other harmful health risks. While your state of Ketosis will not be affected, you will hold a chance of issues like weight gain and the risk of diabetes.

Carbs and Other Ingredients in Diet Coke during Keto

Coke Zero or Diet Coke consists of absolutely 0 sugars and 0 calories. This is excellent news for people on keto diets and low-carb regimes. Several other ingredients are present in this beverage. Let’s see the effects of some of them below.

Flavoring and artificial sweeteners like acesulfame potassium (Ace-K) and aspartame are not an issue for the carbohydrate levels in the body. Although, you might end up experiencing increased chances of health problems in the coming times.

Moreover, Coke Zero also comes with 34 mg worth of Caffeine in a 12-ounce serving which has both negatives and positives. Caffeine is excellent as an energy booster and dehydrates the body if taken in large quantities. The main reason for this is that Caffeine is a diuretic that stimulates the body's need for urination.

The beverage also has Sodium and Potassium, both of which are necessary minerals for your body for proper heart function and other vital body processes. Additionally, Potassium Benzoate is one of the controversial additives present in Diet Coke or Coke Zero. It is strongly recommended to avoid this food item if you are on a keto diet.

How is Diet Coke bad for Ketosis?

Diet Coke is a Dirty Keto food that will help your body potentially reach Ketosis and even lose the hard weight – but it will also pave the path to health problems in the future.

The artificial sweeteners in Diet Coke, aspartame, and acesulfame K are carb-free but lead to gut health problems if consumed on a regular basis. You will also experience elevated cravings upon consumption of Diet Coke, which will cause over-eating and a potential weight gain.


Coke Zero or Diet Coke is okay to be taken on a keto or low carb diet – mainly because of the 0-sugar content making it technically keto-friendly. At the same time, the artificial sweeteners and harmful ingredients make the beverage do worse than good to your body.

If you or your loved one are on a strict keto diet, it is recommended to go for more naturally sweetened drinks to make the most out of the healthy diet.


Can I consume Diet Coke on Keto?

Yes, you can consume Diet Coke on Keto without disrupting the low carbohydrate levels in your body. If you consume the drink in moderate amounts and under control, the drink should not be very harmful to your body.

Is Coke Zero Keto-Friendly?

Coke Zero or Diet Coke can be considered Keto-friendly due to the low net carbs in these drinks. It is still best to avoid this form of ‘Dirty Keto’ foods because of the unhealthy ingredients such as aspartame, potassium benzoate, and acesulfame K.

About the author

The Authentic Keto Team is here to bring you health tips that help you with losing weight fast. We focus on a clean keto diet for beginners because we believe that is the easiest and most simple way to healthy eating. Our keto weight loss tips will not only bring you into ketosis fast but will also help you to improve your mental health, sleep problems, and wellness.

- Our goal is to make keto success easy. -

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