Many people have turned away from regular Coca-Cola for several compelling reasons. A single can contains a hefty 140 calories and a staggering 39 grams of sugar. Moreover, the American version is sweetened with high fructose corn syrup, which some studies suggest might trigger appetite increases and potentially cause more liver damage than regular table sugar (sucrose). With this awareness, soda lovers often find themselves caught in the Coke debate: Coke Zero versus Diet Coke.
It’s important to clarify that diet sodas aren’t exactly health foods, especially when compared to healthier alternatives. Yet, if you’re torn between these two zero-sugar, no-calorie options—or just want to make your whiskey and Coke a bit more guilt-free—you might be asking yourself which is the healthier choice: Coke Zero or Diet Coke?
To put this age-old debate to rest, we consulted a registered dietitian to dive into the nutritional details of both beverages.
About Hone Health
At Hone Health, we are a passionate team comprising health-focused journalists, editors, fitness enthusiasts, medical reviewers, and product testers. To present you with researched-backed insights about energy drinks and nutrition, we’ve consulted registered dietitian nutritionists and examined various reputable studies and medical resources.
About the Expert
Lena Bakovic, M.S., R.D.N., C.N.S.C., is a registered dietitian with Top Nutrition Coaching. She specializes in chronic disease, weight management, and gut health.
Coke Zero vs. Diet Coke: A Closer Look at Ingredients
Coke Zero
Below are all 10 of the ingredients you can find in a can of Coke Zero:
- Carbonated water
- Caramel color
- Phosphoric acid
- Aspartame
- Potassium benzoate (to protect taste)
- Natural flavors
- Potassium citrate
- Acesulfame potassium
- Caffeine
- Phenylalanine
Diet Coke
Catch these 9 ingredients on the back of your Diet Coke:
- Carbonated water
- Caramel color
- Aspartame
- Phosphoric acid
- Potassium benzoate (to protect taste)
- Natural flavors
- Citric acid
- Caffeine
- Phenylalanine
Interestingly, Coke Zero and Diet Coke share nearly identical ingredients. Coke Zero employs two types of artificial sweeteners—aspartame and acesulfame potassium—while Diet Coke relies solely on aspartame. But why should you care? The safety of both sweeteners has been a topic of contention:
- Aspartame: Found in both drinks, aspartame is a zero-calorie sweetener derived from phenylalanine and aspartic acid. Although it is currently recognized by the FDA as safe, some research suggests it may affect mood, lead to toxic liver disease, and even have potential carcinogenic (cancer-causing) properties. Nonetheless, more extensive human studies are still required.
- Acesulfame potassium: Coke Zero adds acesulfame potassium to its ingredient list as another zero-calorie sweetener. Similar to aspartame, this ingredient has sparked debate, as some research indicates potential long-term cancer risks. However, the National Cancer Institute, World Health Organization (WHO), and FDA have established its safety for daily intake at 50 mg per kilogram (kg) of body weight.
Ingredients Verdict: Coke Zero
Both drinks contain similar ingredients, but the order of their components suggests that Diet Coke uses aspartame more prominently. The FDA stipulates that ingredients must be listed by weight, making Coke Zero the more favorable option regarding this ingredient.
Coke Zero vs. Diet Coke: Nutrition detail
- Sweeteners Breakdown
Coke Zero and Diet Coke are both sweetened with artificial sweeteners that are significantly sweeter than regular sugar—200 to 700 times, in fact. Registered dietitian Lena Bakovic, R.D.N., notes that both sodas have no effect on blood sugar levels, which means you won’t experience spikes after consumption like you would with regular Coke.
While Bakovic doesn’t deem Diet Coke substantially healthier due to its reliance on just one artificial sweetener, she does warn that some consumers may want to avoid artificial sweeteners if they’re sensitive to them or concerned about possible carcinogenic effects. Digestive issues, headaches, and other side effects could arise for those who are particularly sensitive to these ingredients.
- Calories, Sodium, and Caffeine: What You Should Know
Both Diet Coke and Coke Zero boast zero calories. Yes, that means they won’t interfere with your fast if you’re intermittent fasting!
In terms of sodium, both contain 40 mg per 12 fl oz serving, which comprises about 2% of your daily sodium intake—considered low.
When it comes to caffeine, Diet Coke has a bit of an edge with 46 mg compared to Coke Zero’s 34 mg. If you’re caffeine-sensitive or want to keep your buzz to a minimum after a few cups of coffee, choosing Coke Zero might be the way to go. Of course, both options offer caffeine-free versions if you’d prefer to skip it altogether.
Nutritional Verdict: A Tie
According to Bakovic, the nutritional profiles of both beverages are quite similar. If caffeine is a concern for you, then Diet Coke’s slightly higher caffeine content could be a deciding factor. But if you’re looking for a caffeine-free option, both drinks are available without it
Taste Test: Coke Zero vs. Diet Coke
Now, let’s get to the moment you’ve been waiting for: which soda actually tastes better? After sampling both, here’s the rundown:Diet Coke has a distinct, slightly bitter aftertaste that’s different from the sugary sweetness of regular Coca-Cola. If you prefer a more subtle flavor, you might find Diet Coke appealing.
In contrast, Coke Zero is remarkably close to the original Coca-Cola taste and has a much sweeter, almost syrupy flavor. Many people find it hard to believe there’s no real sugar in it.
Taste Verdict: Coke Zero
While both Diet Coke and Coke Zero have their unique fan bases, many Reddit users also agree that Coke Zero offers a taste that’s more similar to the classic Coca-Cola. For some, that resemblance might be the game-changer they’ve been looking for.
