That sweet, sweet taste of soda.
Most of us know how refreshing and satisfying a Coke can be. Whether it’s poured over ice on a hot summer day, is accompanying a burger and fries at lunch or is sipped alongside a tub of buttery popcorn during a blockbuster movie, it's a beverage that has a way of hitting the spot.
But no one drinks a can of cola thinking it’s actually good for them. Among the many Coca-Cola varieties that include Classic, Diet, Zero Sugar and flavored options like Cherry Coke and Vanilla Coke, one is probably better for your health than the others.
Here’s what’s different and similar between the most popular varieties of Coca-Cola, plus which ones are likely to cause the fewest issues for your health goals in the long run.
What is Coca-Cola? Is there a difference between Coca-Cola and Coke?
Coca-Cola
is more than just a soft drink; it’s a global brand empire. Founded in 1886 in Atlanta, the company has grown into the world’s largest beverage corporation, boasting over 200 iconic brands. In addition to its flagship cola, Coca-Cola owns well-known drinks like Sprite, Fanta, Powerade, Minute Maid and even the bottled water brand Dasani.
Its most iconic product, Coca-Cola Classic (usually just called Coke), is a carbonated soft drink made primarily of carbonated water, high-fructose corn syrup (or cane sugar in some countries), caramel coloring, phosphoric acid, caffeine and unspecified “natural flavors,” according to its nutrition label. Sometimes cherry- or vanilla-flavored syrup are also added to the formulation for Cherry Coke and Vanilla Coke varieties.
Thanks to its sweetness, distinct flavor, caffeine content and fizz, Classic Coke has become one of the most consumed beverages worldwide. But its high sugar content has also made it and other sugary drinks a frequent target of health experts.
“Regular sodas are one of the leading sources of added sugars in the American diet,” Caroline Susie, a registered dietitian and national spokesperson for the Academy of Nutrition and Dietetics, previously told USA TODAY. Indeed, a single 20-ounce bottle of Classic Coke contains a staggering 65 grams of added sugars, which is about 130% the recommended daily limit.
In response to growing concerns over sugar intake, Coca-Cola introduced Diet Coke in 1982 and Coke Zero in 2005. (The same drink was rebranded as Coca-Cola Zero Sugar in 2017, though it's still often called Coke Zero). Both options are sugar-free, using artificial sweeteners instead. But both varieties do differ in formulation: Diet Coke uses only aspartame and has its own distinct flavor, while Coke Zero combines aspartame with acesulfame potassium – and sometimes stevia – giving it a flavor profile some consumers feel is closer to Coca-Cola Classic, Kristina Cooke, a licensed nutritionist specializing in diabetes treatment and prevention, also previously told USA TODAY.
Is Diet Coke bad for you?
No dietitian, nutritionist or physician would classify either Diet Coke or Coke Zero as healthy, but many would call them healthier alternatives to regular soda. At the same time, even as they eliminate added sugars, some of the sugar substitutes they contain come with controversies of their own.
For instance, in 2023, the World Health Organization’s International Agency for Research on Cancer classified aspartame as “possibly carcinogenic to humans,” citing limited evidence linking high intake to liver cancer in some studies. Despite this, major regulatory agencies including the U.S. Food & Drug Administration (FDA) and the European Food Safety Authority (EFSA) continue to deem aspartame safe when consumed in moderation. Still, the science isn’t settled.
And there are other considerations as well including additional research that has raised concerns that high consumption of artificial sweeteners may increase appetite, disrupt gut bacteria and even contribute to insulin resistance. Though these effects tend to be subtle and depend heavily on individual factors, they cast some doubt on the assumption that diet soda supports weight loss or is better for overall health.
Meanwhile, the health concerns surrounding Classic, Cherry and Vanilla Coke's high sugar content are more clear-cut. Excess sugar intake is strongly linked to obesity, type 2 diabetes, fatty liver disease and heart disease.
Regardless of the variety being diet or otherwise, Susie emphasizes that soda offers “zero essential nutrients” and often displaces healthier beverage options like water, milk or unsweetened tea.
What is the healthiest Coke?
If you're looking to choose between all these less-than-ideal options, the “healthiest” Coke is probably Coke Zero Sugar, but only by a small margin.
That’s largely because Classic Coke (and its flavored Cherry and Vanilla varieties) are not only loaded with added sugars but also has a significant number of empty calories. A 20-ounce bottle of Classic Coke contains about 240 calories, energy that’s quickly burned without the benefit of fiber or other nutrients and sometimes leading to glucose spikes, sugar crashes and weight gain.
Both Diet Coke and Coke Zero Sugar sidestep these problems by being both calorie- and sugar-free. “That alone makes them better choices,” Cooke says. And since both contain the same amount of aspartame, the risks associated with artificial sweeteners are similar either way.
Where Coke Zero has a slight edge though is in its lower caffeine content: 34 milligrams per 12-ounce can compared to 46 milligrams of caffeine in Diet Coke. While moderate amounts of caffeine are generally considered safe, excessive intake may contribute to anxiety, disrupted sleep and elevated heart rate and blood pressure.
Despite this edge, either Diet Coke or Coke Zero is almost certainly a smarter pick than the classic or flavored varieties. “For those aiming to reduce added sugar intake, especially for weight management or diabetes, diet soda can be a reasonable alternative to regular soda,” Susie says.
But quantity may ultimately matter more than whichever variety you choose. “Rather than focusing on which of these beverage options someone chooses, I help people focus on how often they drink soda and how much they consume as part of their overall eating pattern,” Shelley Rael, a registered dietitian and nutritionist based in Albuquerque, New Mexico, previously told USA TODAY. “A Coke or a Diet Coke here and there isn’t a dealbreaker for health; it’s daily or excessive intake that is the bigger concern."
This article originally appeared on USA TODAY: What's the difference between Diet Coke and Coke Zero?
