Is Coke Zero Bad For You? A Registered Dietitian Answers

Is Coke Zero Bad For You? A Registered Dietitian Answers

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Coke Zero, also called Coke Zero Sugar, is a zero-calorie soda that many consumers consider to be healthier than regular Coke. The brand claims that this drink “has a great taste with zero sugar or calories.”

But does Coke Zero have any unhealthy ingredients? Is it healthier or less healthy than regular Coke? How is it sweetened? And how do real customers describe its taste and effects?

In this article we’ll answer all of these questions and more as we analyze the ingredients in Coke Zero based on medical studies to give our take on whether it’s bad for you or if it’s a healthy, low-calorie option.

We’ll also review the ingredients in regular Coke to compare which is healthier, and share customer reviews including taste tests.

Ingredient Analysis

Coke Zero ingredients

The ingredients in Coke Zero are shown above. Aspartame and acesulfame potassium are the sweetening ingredients, and both are artificial sweeteners.

Aspartame was shown in a medical review published in the Environmental Health journal to be potentially carcinogenic (cancer-causing) based on clinical trials on animals.

Acesulfame potassium has been shown in a clinical trial to cause harm to the intestinal tract.

Phosphoric acid is a flavor enhancer that may have a negative impact on bone health. As we documented in our analysis of Diet Coke ingredients, medical studies have shown that women regularly consuming drinks containing phosphoric acid have lower blood calcium levels, which can lead to osteoporosis.

Potassium benzoate is a preservative which was shown in a clinical trial published in the Food and Chemical Toxicology journal to be toxic to human cells.

Caffeine is also included in this drink, but it’s a relatively low amount that shouldn’t have a negative effect on the vast majority of consumers. Only 34 milligrams (mg) of caffeine is included, which is equivalent to around 33% of the dose in one cup of coffee.

Overall, we consider Coke Zero to be bad for you. It provides essentially zero nutrition and contains a number of ingredients that may be harmful to human health according to the clinical trials cited in this section.

But how does it compare to other Coke drinks? We’ll analyze in the next section.

Is Coke Zero Healthier Than Regular Coke?

Coke Nutrition Facts

The Nutrition Facts for regular Coke (20 ounce bottle) are shown above. The most notable thing is the added sugar.

Coke contains 65 grams (g) of added sugar per bottle, which exceeds the Daily Value by 30%. A 2019 medical review reports that added sugar consumption in excess is associated with increased risk of obesity, diabetes, cardiovascular disease and some types of cancer.

The added sugar is actually in the form of high fructose corn syrup rather than regular white sugar. This may be even unhealthier. As we documented in our review of Ghost Protein Powder, high fructose corn syrup is strongly linked to obesity in clinical trials.

The two ingredient lists are very similar. The main difference is that Coke is sweetened with high fructose corn syrup and Coke Zero is sweetened with artificial sweeteners.

We consider Coke Zero to be healthier than regular Coke, because the negative health effects of such a high dose of high fructose corn syrup seem clearer in our opinion than that of artificial sweeteners.

But is Coke Zero healthier than Diet Coke? The ingredients in Diet Coke are shown below:

Diet Coke ingredients

You’ll note that the ingredients are extremely similar to Coke Zero.

There is no acesulfame potassium in Diet Coke, but there is citric acid which is a flavor enhancer shown in a medical review published in the Toxicology Reports journal to cause whole-body inflammation in some individuals.

We consider Diet Coke to be healthier than Coke Zero because it only contains one artificial sweetener.

Is Diet Soda Bad for the Body and Brain?

An interesting, animated video published by Insider Science examined whether diet soda intake could be harmful to the body and brain. The video is only three minutes long:

Doctor Discusses Health Effects of Coke Zero

A medical doctor named Dr. Idz discussed the health effects of Coke Zero on the H3 podcast:

Our Healthy Soda Pick

Olipop is our healthy soda pick.  

This natural soda uses no flavoring additives or refined sugar, and is instead flavored with nutritionally-rich botanical ingredients like mandarin juice (which is clinically shown to be a potent antioxidant), nopal cactus and calendula flower.

The cans have only 2 to 5 g of added sugar from natural sources like cassava root syrup and apple juice.

Stay up-to-date on our research reviews


We consider Coke Zero to be bad for you, although nearly anything in moderation in the context of a healthy diet is likely fine. So while we certainly wouldn’t recommend drinking Coke Zero daily, if it’s an occasional indulgence it shouldn’t be a problem.

Coke Zero contains two artificial sweeteners that may have negative health effects according to clinical research, but we still consider Coke Zero to be healthier than regular Coke due to the high amount of added sugar in regular Coke in the form of high fructose corn syrup.

We would recommend Diet Coke over Coke Zero because it has one fewer artificial sweetener.

There are more options today for whole-food-based soda options than there were in the past, with brands selling soda alternatives sweetened naturally with fruit. We consider these to be healthier options than commercial soda.