Exploring Coke Zero’s Fit in Keto Dieting: Benefits and Cautions

Keto (Low Carb) | Written by Nathan Petitpas | Updated on 14 August 2024

A woman with red fingernails is holding a 3/4 full glass bottle of Coca-Cola labeled "zero sugar," with water droplets glistening on the outside, as she questions whether Coke Zero is keto.

While Coke Zero is one of the most popular diet beverages, its keto and low-carb status, or whether it should be avoided as an unhealthy drink, is a topic of discussion.1

We’ll be the fist to admit that Coke Zero has a crave-worthy flavor and minimal aftertaste compared to other low-calorie drinks but that might not outweigh some of the less than healthy ingredients within it.

To get to the bottom of this, let’s examine the current research to come to a conclusion before reviewing carbonated keto alternatives to diet beverages.

How Many Carbs Are in Coke Zero?

Coca-Cola Zero Sugar has no calories, carbs, fat, or protein. A 12 ounce can of Coke 0 contains:

  • 40 milligrams of sodium
  • 60 milligrams of potassium
  • 34 milligrams of caffeine (about ¼ the caffeine found in 12 ounces black coffee)

The ingredients in Coke Zero are:

  • Carbonated water
  • Caramel color
  • Phosphoric acid
  • Aspartame (87 milligrams)
  • Potassium benzoate
  • Natural flavors
  • Potassium citrate
  • Acesulfame potassium (also known as acesulfame K – 47 milligrams)
  • Caffeine

Coke Zero is carb free. It’s sweetened with two different artificial sweeteners, aspartame and acesulfame K.

Coke Zero As Keto-Friendly Drink

Strictly speaking, Coke Zero is keto-friendly; this drink contains zero calories and zero carbs. Many people will raise various objections to this claim, suggesting that Coke Zero can cause weight gain, exacerbate digestive problems, or even cause cancer.

A splashing liquid of a refreshing soda Coke with bubbles against a white backdrop.

Source: brainmaster via Canva.com2

We’ll examine those claims in detail.

Can Diet Coke Kick Me Out of Ketosis?

Since Coke Zero and Diet Coke contain zero carbs, they cannot kick you out of ketosis. Only food and drink that contains carbohydrates can do so.

Additionally, research indicates that diet soda does not increase insulin resistance or diabetes risk.3

Diet Coke vs Coke Zero

When comparing Coke Zero and Diet Coke keto dieters can rest easy. Both drinks are carb- and calorie-free, and have similar ingredients. The main difference is taste.

Coke Zero tastes more like Classic Coca-Cola, while Diet Coke has a slightly ‘lighter’ taste.

The Downsides of Coke Zero & Reasons It May Be an Unhealthy Drink

Many people demonize diet beverages, claiming that the artificial sweeteners it contains cause cancer, disrupt gut health, have a negative impact on mood, and cause weight gain. However, the research on these topics is often misinterpreted or blown out of proportion.

Coke Zero has been FDA-approved since 2005. The ADI (Acceptable Daily Intake) of aspartame set by the FDA is 50 milligrams of aspartame per kilogram of bodyweight per day.

A moist, clear glass filled with cold carbonated soda and ice cubes displayed against a sky-blue backdrop.

Source: George Fairbairn via Canva.com4

To put this in perspective, a 140-pound person would have to drink 36 cans of Coke Zero in one day to reach this limit.

The ADI of acesulfame K is 15 milligrams per kilogram of body weight. That same 140-pound person would have to drink 20 cans of Coke Zero in a day to reach this limit.

The Link Between Aspartame & Cancer in Rats (Debated)

The studies that link aspartame and cancer in rats rely on dosing rats with high quantities of aspartame. For example, in this study, rats were dosed with quantities equivalent to the ADI in the US.5

A 200-pound person would need to drink 51 cans of Coke Zero to mimic this response. This is nearly 5 gallons of Coke Zero! Drinking that quantity of ANY liquid would cause immediate physical problems that would be far more significant than any negative side effects from artificial sweeteners.

As far as research with humans, a study involving over 100,000 adults indicated that consuming higher-than-average quantities of aspartame and acesulfame-K may increase cancer risk.6 However, consuming traditionally sweetened soda carries associated cancer risk as well.

Ultimately, moderate or occasional consumption of Coke Zero is not associated with significant cancer risk.

Possible Mood Changes

Drinking large quantities of diet beverages (18 cans per day for a person weighing 140 lbs.) may increase irritability and depression and decrease brain function.7 Again, this is a question of dosage.

Besides, the amount of caffeine in this quantity of Coke Zero would impact mood far more than the artificial sweeteners.

Potential Digestive Problems

Some experiments performed on mice indicate that the artificial sweetener acesulfame K may have a negative impact on gut health.8 However, these mice were given a dose equivalent to 140 lb. person drinking 50 cans of Coke Zero per day.

Obviously, a pattern is emerging. Unless you’re drinking extreme and unsustainable quantities of diet beverages, these various health concerns are non-issues.

The Benefits of Coke Zero as a Low Carb Treat for Keto & Weight Loss

In moderation, research indicates diet beverages may help with weight loss and weight loss maintenance.9 This is likely because it can replace other, less-healthy drinks and help people adhere to keto diet plans without feeling deprived.

One to two 12-ounce cans per day is likely a good limit for most people.

Reports that diet beverages cause weight gain by spiking insulin or creating cravings are largely unsubstantiated. As noted above, artificial sweeteners do not contribute to diabetes risk and may even help maintain weight loss.

Ultimately, this is a personal consideration.

Diet beverages may help you adhere to your diet and could potentially impact your weight.

It’s worth experimenting to find out for yourself.

Whether you consider to consume Coke Zero should depend on whether it helps YOU stick to your keto weight loss plan.

Three red unopened cans of carbonated soda stuck in a space filled and surrounded with lots of ice cubes.

Source: DAPA Images via Canva.com10

Liquid calories can make or break weight loss efforts for many people, and ultimately, diet beverages should not be a huge source of concern. Sodas sweetened with high fructose corn syrup, alcohol, and other carb-laden beverages are much more likely to contribute to health concerns in the long run.

Some people use Coke Zero and other diet beverages as chaser for liquor to reduce empty calorie intake, a key strategy in losing weight gained from alcohol, and to prevent weight gain in the first place.

In the end, prioritize drinking ample water and incorporating beverages like green tea, known to actively promote better health and weight loss, as they are among the drinks that can reduce belly fat. Drink diet beverages in moderate amounts if you enjoy the taste and it helps you stick to your keto goals.

In this way, it can aid your weight loss efforts and serve as a zero-calorie treat when cravings strike!

Keto-Friendly Coke Zero Alternatives

While Coke Zero can be part of a successful keto diet, it’s worth exploring other alternatives as well, making the question of whether Coke Zero is keto just the tip of the iceberg.

Carbonated beverages can help fill your stomach when you’re feeling hungry and some of the options on this list even provide additional health benefits, like BCAAs, probiotics, and essential minerals.

Sparkling Water (various brands, including La Croix)

Twenty-seven cans of LaCroix sparkling water that comes in different variation such as Pamplemousse, peach-pear, berry, and keylime, arranged in a three-layer stack and displayed on a white surface against a white backdrop.

Source: WIRED on Youtube11

While La Croix started the trend, there are dozens of sparkling water options available now.

Try Perrier or Topo Chico if you prefer plain bubbles.

For a burst of fruit flavor, popular brands include Bubbly, Waterloo, and Aha. These brands have tons of tasty flavors, and if you prefer some sweetness, it’s easy to add a few drops of a keto sweetener like liquid stevia.

Zevia

Zevia is the most popular stevia-sweetened soda on the market today. For people who can’t lay their concerns about artificial sweeteners to rest, this is a great alternative to Coke Zero and other diet beverages.

Three opened cans of Zevia zero calorie soda that comes in three different flavors such as cola in blue color, cream soda in yellow color, and Dr Zevia in red color.

Source: Tami Dunn on Youtube12

Zevia comes in 18 different flavors, including:

  • Cran-Raspberry
  • Fruit Punch
  • Orange Cream
  • Black Cherry
  • Caffeine Free Cola
  • Cherry Cola
  • Cola
  • Creamy Root Beer
  • Cream Soda
  • Dr. Zevia
  • Ginger Ale
  • Ginger Root Beer
  • Grape
  • Grapefruit Citrus
  • Lemon Lime Twist
  • Mountain Zevia
  • Orange
  • Strawberry

Virgil’s

Virgil’s sells zero sugar handcrafted soda sweetened with erythritol and stevia. For people looking for a craft soda experience (perhaps to use as a mixer with high-proof alcohol), this brand is the perfect choice.

Two big men, one wearing a black t-shirt, and the other one wearing a flannel is checking different flavors of Virgil's zero sugar soda in a room with bookshelves in the background.

Source: Two Dudes Reviews on Youtube13

Their sodas come in slimline cans and glass bottles. Flavors include:

  • Grapefruit
  • Dr. Better
  • Ginger Ale
  • Root Beer
  • Vanilla Cream
  • Black Cherry
  • Lemon Lime
  • Cola
  • Orange Cream

Fit Soda

This product is a unique combination of healthy soda and sports drink. It’s made with electrolytes and branched-chain amino acids (BCAAs) to help with workout recovery.

Four cans of Fit Soda that comes in different flavors such as orange creamsicle, sparkling citrus, root bear vanilla float, and black cherry cola displayed on a white surface against a white backdrop.

Source: Fit Soda Media on Youtube14

Containing zero caffeine, it’s sweetened with sucralose (also known as Splenda). Flavors include:

  • Orange Cream
  • Root Beer Vanilla Float
  • Black Cherry Cola
  • Sparkling Citrus

Poppi

This is the only product on this list that isn’t 100% calorie- and carb-free, but since it contains only 5 grams net carbs per can, plus beneficial probiotics, it’s worth including. Initially featured on Shark Tank, Poppi soda is made with apple cider vinegar, organic fruit juice, stevia, and organic cane sugar.

Two cans of Poppi prebiotic soda in different flavors such as strawberry lemon in pink can and watermelon in light-green can displayed on top of a white shiny surface.

Source: Ace Reviews on Youtube15

Each can contains 25 calories. Flavors include:

  • Cherry Limeade
  • Strawberry Lemon
  • Raspberry Rose
  • Ginger Lime
  • Orange
  • Watermelon
  • Classic Cola
  • Doc Pop
  • Root Beer

Sparkling Ice

This popular zero-calorie drink, available at most grocery stores, comes in a staggering assortment of flavors and varieties. Keto dieters should remember that Sparkling Ice drink is sweetened with sucralose.

However, it’s also fortified with vitamins and antioxidants.

Six bottles of Sparkling Ice in different flavors such as cherry lime, pink grapefruit, peach nectarine, orange mango, coconut pineapple, and kiwi strawberry, and one close up of a bottle of Sparkling Ice in black cherry flavor on the right side.

Source: TheStreet on Youtube16

It comes in caffeinated flavors for an energy drink experience. Plus, it’s quite affordable! Flavors include:

  • Grape Raspberry
  • Black Cherry
  • Berry Lemonade
  • Black Raspberry
  • Fruit Punch
  • Cherry Limeade
  • Strawberry Watermelon
  • Strawberry Lemonade
  • Kiwi Strawberry
  • Pink Grapefruit
  • Peach Nectarine
  • Orange Mango
  • Coconut Pineapple
  • Classic Lemonade
  • Lemon Lime
  • Cherry Vanilla +Caffeine
  • Black Raspberry +Caffeine
  • Blue Raspberry +Caffeine
  • Watermelon Lemonade +Caffeine
  • Tropical Punch +Caffeine
  • Strawberry Citrus +Caffeine
  • Citrus Twist +Caffeine

Coke Zero is a low-carb treat that is ‘semi-healthy’. It can help with weight loss and keto adherence since it contains no calories or carbs.

Now that you know whether Coke Zero is keto, you can enjoy it as an occasional keto treat with confidence.

Frequently Asked Questions

Is Cherry Coke Zero Suitable For A Keto Diet?

Yes, this cherry-flavored variation on Coke Zero contains zero calories or carbs, making it keto-friendly. It’s also available in Coca-Cola Cherry Vanilla Zero Sugar.

Is Coke Zero Vanilla Keto-Friendly?

Yes, this fan favorite is calorie- and carb-free. Add a scoop of keto vanilla ice cream for a delicious keto Coke float!

Is It Safe To Drink Diet Beverages Every Day?

Drinking 1-2 cans of diet beverages each day is perfectly safe. The amount of artificial sweeteners found in this quantity of diet beverages are nowhere near the Acceptable Daily Intake set by governing boards like the FDA.

Additionally, research documenting the negative health effects of artificial sweeteners is based on much higher quantities than that found in 1-2 cans.

What Are the Best Keto-Friendly Drinks?

Diet beverages, unsweetened coffee and tea, sparkling water, and high-proof alcohol can all fit within a keto diet. And if you’re wondering is Diet Dr. Pepper keto or is Propel keto, fortunately, these and other popular sugar-free beverages fit on the keto diet.


References

1“Introducing Coke Zero Sugar | Taste For Yourself | Coca-Cola.” YouTube, 31 August 2017. Accessed 22 April 2023. <https://www.youtube.com/watch?v=ge4DT9RJICQ>

2brainmaster. Canva. Accessed 22 April 2023. <https://www.canva.com/photos/MAEEERCIYDE-splashing-coke-soda/>

3Jensen, P. N., Howard, B. V., Best, L. G., O’Leary, M., Devereux, R. B., Cole, S. A., MacCluer, J. W., Ali, T., Lee, E. T., Yeh, F. L., Yeh, J., Umans, J. G., & Fretts, A. M. (2020). Associations of diet soda and non-caloric artificial sweetener use with markers of glucose and insulin homeostasis and incident diabetes: the Strong Heart Family Study. European journal of clinical nutrition, 74(2), 322–327. <https://doi.org/10.1038/s41430-019-0461-6>

4Fairbairn, George. Canva. Accessed 22 April 2023. <https://www.canva.com/photos/MAEMAcIkZM8-full-glass-of-carbonated-soda-sofr-drink/>

5Landrigan, P. J., & Straif, K. (2021). Aspartame and cancer – new evidence for causation. Environmental health : a global access science source, 20(1), 42. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8042911/>

6Debras, C., Chazelas, E., Srour, B., Druesne-Pecollo, N., Esseddik, Y., Szabo de Edelenyi, F., Agaësse, C., De Sa, A., Lutchia, R., Gigandet, S., Huybrechts, I., Julia, C., Kesse-Guyot, E., Allès, B., Andreeva, V. A., Galan, P., Hercberg, S., Deschasaux-Tanguy, M., & Touvier, M. (2022). Artificial sweeteners and cancer risk: Results from the NutriNet-Santé population-based cohort study. PLoS medicine, 19(3), e1003950. <https://pubmed.ncbi.nlm.nih.gov/35324894/>

7Lindseth, G. N., Coolahan, S. E., Petros, T. V., & Lindseth, P. D. (2014). Neurobehavioral effects of aspartame consumption. Research in nursing & health, 37(3), 185–193. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5617129/>

8Bian, X., Chi, L., Gao, B., Tu, P., Ru, H., & Lu, K. (2017). The artificial sweetener acesulfame potassium affects the gut microbiome and body weight gain in CD-1 mice. PloS one, 12(6), e0178426. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5464538/>

9Peters, J. C., Beck, J., Cardel, M., Wyatt, H. R., Foster, G. D., Pan, Z., Wojtanowski, A. C., Vander Veur, S. S., Herring, S. J., Brill, C., & Hill, J. O. (2016). The effects of water and non-nutritive sweetened beverages on weight loss and weight maintenance: A randomized clinical trial. Obesity (Silver Spring, Md.), 24(2), 297–304. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4744961/>

10DAPA Images. Canva. Accessed 22 April 2023. <https://www.canva.com/photos/MADFHd5DTrs-soda-cans-covered-in-ice/>

11“What the Hell is in LaCroix? | WIRED.” YouTube, 15 December 2016. Accessed 22 April 2023. <https://www.youtube.com/watch?v=DPK297AbxMQ&t>

12“Zevia: Cola, Cream Soda & Dr. Zevia Review.” YouTube, 17 July 2015. Accessed 22 April 2023. <https://www.youtube.com/watch?v=D-mgj-O-izA>

13“Virgil’s New All-Natural Zero Sugar Orange Soda.” YouTube. Accessed 22 April 2023. <https://www.youtube.com/watch?v=hlX-TPKnE_w&t>

14“THE GREATEST WAY TO HYDRATE ON THE PLANET.” YouTube. Accessed 22 April 2023. <https://www.youtube.com/watch?v=SQ-FLGD16v0>

15“POPPI – Prebiotic Soda Review (As Seen on Shark Tank!).” YouTube, 11 December 2021. Accessed 22 April 2023. <https://www.youtube.com/watch?v=yt95WVeKxds&t>

16“Sparkling Ice Is Making Strong Headway in the Beverage Battle.” YouTube, 13 June 2016. Accessed 22 April 2023. <https://www.youtube.com/watch?v=PAKJ4CSQPZI&t>

About the Author

Nathan Petitpas

Nathan has been a fitness enthusiast for the past 12 years and jumps between several types of training such as bodybuilding, powerlifting, cycling, gymnastics, and backcountry hiking. Due to the varying caloric needs of numerous sports, he has cycled between all types of diets and currently eats a whole food diet. In addition, Nathan lives with several injuries such as hip impingement, spondylolisthesis, and scoliosis, so he underwent self-rehabilitation and no longer lives with debilitating pain.