The Best and Worst Diet Sodas—Ranked!
Although we're familiar with the ill effects of artificial sweeteners, one study went ahead and shed light on the frightening link between zero-calorie artificial sweeteners to diabetes and obesity. And to make matters worse, another study revealed that daily diet soda drinkers grow about two-and-a-half more inches of belly fat each decade than those who don't drink the stuff.
"Diet drinks cause insulin to be released in your gut because their artificial sweeteners are sweet like sugar, and that actually prevents weight loss," Miriam Jacobson, RD, CDN, told us. "Insulin is your body's primary fat-storage hormone, so it will have the body hold onto any extra fat."
Diet sodas also harm the immune system because their acidity causes havoc with our gut bacteria. And the phosphoric acid that's present in many cans has been shown to leach calcium from our bones.
While every diet soda is bad for you, some are clearly worse than others. We looked at various brands and closely imagined the ingredients of popular diet sodas in America. Read on to discover where your favorite cola landed—and discover our No. 1 pick, which might become your new go-to. Plus, don't miss We Tasted 9 Diet Sodas & This Is the Best.
How We Ranked Them
First, we measured the amount of artificial sweetener in each soda, paying special attention to aspartame, the most pervasive sweetener. The low-calorie sugar alternative, made by joining two amino acids with an alcohol, is 180 times sweeter than sugar—and the subject of controversy. Some researchers claim to have linked aspartame to brain tumors and lymphoma, but the FDA insists the sweetener is safe for humans. We recommend you limit your consumption. And given the public's interest in limiting their aspartame intake, we gave demerits to diet sodas with high aspartame counts.
Then, also docked points for high levels of ingredients you wouldn't expect in your beverage—like vegetable oils and tree bark—and gave high marks to brands with more natural blends.
And now, without further ado here are popular diet sodas ranked from the worst options to the one that isn't all that bad. And while you're uncovering the truth about sodas, be sure to check out 108 Most Popular Sodas Ranked By How Toxic They Are.
Diet Mountain Dew
Ingredients: Carbonated Water, Concentrated Orange Juice, Citric Acid, Natural Flavor, Potassium Benzoate (Preserves Freshness), Citrus Pectin, Aspartame, Potassium Citrate, Caffeine, Sodium Citrate, Acesulfame Potassium, Sucralose, Gum Arabic, Sodium Benzoate (Preserves Freshness), Calcium Disodium EDTA, Yellow 5
Previously, this soda with the lime-green hue used to contain brominated vegetable oil, which has bromine (something that was also said to be found in brominated flame retardants). In citrus-flavored soda drinks, BVO acts as an emulsifier, but it has since been removed from the Diet Dew's list of ingredients. Still, there are plenty of reasons why this diet soda is still one to avoid!
Fresca Original Citrus
Ingredients: Carbonated Water, Citric Acid, Concentrated Grapefruit Juice, Potassium Citrate, Aspartame, Potassium Sorbate, Acacia Gum, Acesulfame Potassium, Natural Flavors, Glycerol Ester of Rosin, Potassium Benzoate and Calcium Disodium EDTA, Carob Bean Gum
After a long day of hard work and play, do you like to sit back and relax and crack open a can of Glycerol Ester of Rosin? Didn't think so! The wood resin is added to many fruit sodas to help the fruit-flavored oils mix better with the water. While it's not necessarily harmful, let us repeat: you're drinking oil and water…
Ingredients: Carbonated Water, Cane Sugar, Caramel Color, Natural Flavors, Phosphoric Acid, Potassium Benzoate, Caffeine, Stevia Leaf Extract
If you think you're doing yourself a favor by opting for Coca-Cola's sugar- and stevia-sweetened beverage over the traditional red can, you might want to take a closer look at the nutrition label. Its natural packaging is there to distract you from the cold, hard facts: A 12-ounce can of the stuff contains 24 grams of sugar, which is especially troubling given that The American Heart Association recommends men should consume no more than 36 grams of added sugar per day, and women shouldn't have more than 25 grams. The World Health Organization even recommends we reduce our daily sugar intake to about 25 grams a day to most effectively ward off obesity, heart disease, cancer, and diabetes. In fact, the green can packs in as much sugar as you'll get from eating five Oreo cookies.
Ingredients: Carbonated Water, Sugar, Caramel Color, Phosphoric Acid, Natural Flavor, Caffeine, Purified Stevia Leaf Extract
Pepsi's answer to Coca-Cola Life—also made with pure sugar and Stevia Leaf extract—says it's "all the fun you love about Pepsi with 30% less sugar than regular Pepsi." Stay "true" to yourself and instead satisfy your craving with one of best proteins for weight loss!
Dr. Pepper Ten
Ingredients: Carbonated Water, High Fructose Corn Syrup, Caramel Color, Phosphoric Acid, Aspartame, Sodium Benzoate (preservative), Caffeine, Natural and Artificial Flavors, Acesulfame Potassium, Sodium Phosphate
Only the soda companies could blend two evils—high fructose corn syrup and artificial sweeteners—and market it as a healthier choice. The Ten line does just that. "Both Ten and a zero-calorie brand are bad," Isabel Smith, MS, RD, CDN, tells us, "but for the sake of fewer bad ingredients, the zero-calorie is better." Dr. Pepper Ten may have just 10 calories per serving, but it also contains sneaky substances such as aspartame and caramel color. To easily burn off any of these sodas—without spending hours in the gym—don't miss this list of the essential best ways to speed up your metabolism.
Pepsi Zero Sugar
Ingredients: Carbonated Water, Caramel Color, Phosphoric Acid, Aspartame, Potassium Benzoate (preserves freshness), Caffeine, Natural Flavor, Acesulfame Potassium, Citric Acid, Calcium Disodium EDTA, Panax Ginseng Root Extract
Is your local store sold out of Coke Zero Sugar? Try this wannabe, which adds extra caffeine from ginseng to fool folks into thinking this is an all-natural energy drink.
Mello Yello Zero
Ingredients: Carbonated Water, Citric Acid, Aspartame, Sodium Benzoate, EDTA, Acacia, Potassium Citrate, Acesulfame Potassium, Caffeine, Sucrose Acetate Isobutyrate, Natural Flavors, Coconut Oil, Yellow #3.
You know when you add some Mentos to a two-liter Diet Coke and the whole thing explodes? (Don't try that at home.) That's thanks to the Gum Acacia in the candy, a natural emulsifier, which is also in this soda.
Ingredients: Carbonated Water, Citric Acid, Potassium Citrate, Aspartame, Natural Flavors, Potassium Benzoate, Modified Food Starch, Acesulfame Potassium, Yellow 6, Glycerol Ester of Rosin, Coconut Oil, Red 40.
Just like its full-calorie cousin, Fanta Zero is an unsavory blend of oils and artificial colors. Skip!
Sunkist Zero Sugar
Ingredients: Carbonated Water, Citric Acid, Sodium Citrate, Sodium Benzoate (preservative), Aspartame, Malic Acid, Modified Food Starch, Natural Flavors, Caffeine, Ester Gum, Acesulfame Potassium, Yellow 6, Red 40
What do you get when you combine carbonated water with aspartame and a host of hard-to-pronounce chemicals? This citrus-inspired sip. It gets its alluring orange color from Yellow 6 and Red 40. A Journal of Pediatrics study linked Yellow 5 to hyperactivity in children and Canadian researchers found Red 40 to be contaminated with known carcinogens.
Ingredients: Carbonated Water, Caramel Color, Phosphoric Acid, Aspartame, Potassium Sorbate and Potassium Benzoate, Artificial and Natural Flavors, Acesulfame Potassium, Caffeine, Monosodium Phosphate, Lactic Acid, Polyethylene Glycol
A "spicy" cherry soda found mostly in the South, Pibb Zero contains propylene glycol, a preservative, thickening agent, and stabilizer, also used as antifreeze to de-ice airplanes, as a plasticizer to make polyester resins, and found in electronic cigarettes. In other words, it's a nutritional zero.
Diet Barq's Root Beer
Ingredients: Carbonated Water, Caramel Color, Potassium Sorbate and Sodium Benzoate, Aspartame, Citric Acid, Acesulfame Potassium, Artificial and Natural Flavors, Acacia, Potassium Chloride
As with aspartame, we recommend you limit Acesulfame Potassium, a zero-calorie sweetener that often appears with sucralose or aspartame to create a flavor closer to sugar (it's 200 times sweeter). Although the FDA does not recognize it as a carcinogen, some experts disagree; the sweetener has been found to cause adverse effects in mice's gut microbiome. It's used here to sweeten the root beer, but you'll also find it in Diet Pepsi, Fresca, and Coke Zero Sugar. For decadent fat-burners without the guilt, don't miss this list of the best healthy carbs to eat for weight loss!
Diet Mug Root Beer
Ingredients: Carbonated Water, Caramel Color, Sodium Benzoate, Aspartame, Citric Acid, Natural and Artificial Flavor, Calcium Disodium EDTA (To Protect Flavor), Quillaia Extract
The ingredient to worry about here is not the odd-sounding Quillaia tree bark, but rather the caramel color and aspartame.
Diet Dr. Pepper Cherry
Ingredients: Carbonated Water, Caramel Color, Natural and Artificial Flavors, Aspartame, Sodium Benzoate (preservative), Citric Acid, Phosphoric Acid, Caffeine, Malic Acid, Sodium Phosphate, Red 40
The cherry version of Diet Dr. Pepper is worse than the original because of the artificial color Red 40, which Canadian researchers found to be contaminated with known carcinogens.
Diet Dr. Pepper Cherry Vanilla
Ingredients: Carbonated Water, Caramel Color, Natural and Artificial Flavors, Aspartame, Sodium Benzoate (preservative), Citric Acid, Phosphoric Acid, Caffeine, Malic Acid, Red 40
Like old school Cherry, the Vanilla also has Red 40—and no actual vanilla.
Dr. Brown's Diet Black Cherry
Ingredients: Carbonated Water, Cherry and Other Natural Flavors, Citric Acid, Aspartame, Sodium Benzoate, Sodium Citrate, Caramel Color and Artificial Color (Red 40)
Don't trust a "doctor" who prescribes caramel color and Red 40. Leave this drink out of your fridge for the sake of better health.
Diet Dr. Pepper
Ingredients: Carbonated Water, Caramel Color, Aspartame, Phosphoric Acid, Artificial and Natural Flavors, Sodium Benzoate, Caffeine.
We know it's likely your favorite guilty pleasure, but keep this Doctor away and instead don't miss these ways to lose belly fat!
Diet Mug Cream Soda
12 fl oz: 0 calories, 0 g carbs (0 g sugar)
Ingredients: Carbonated Water, Natural and Artificial Flavor, Sodium Benzoate (preserves freshness), Aspartame, Citric Acid, Caramel Color, Yucca Mohave Extract, Calcium Disodium EDTA
Don't worry too much about the Yucca Mohave Extract—it just makes your artificially-sweetened carbonated water foamy. Instead, wonder: Where's the cream?
Coke Zero Sugar
Ingredients: Carbonated Water, Caramel Color, Phosphoric Acid, Aspartame, Potassium Benzoate, Natural Flavors, Potassium Citrate, Acesulfame Potassium, Caffeine
Coca-Cola rebranded Coke Zero as Coke Zero Sugar back in summer 2017. Like Coke Zero, Coke Zero Sugar is sweetened with a mix of aspartame and Ace-K. The only difference? The soda giant tweaked its blend of proprietary natural flavors. Don't let the fact that this diet drink tastes like real Coke fool you! Thing is, it could make you gain weight like the real thing, too.
"Even though diet drinks are calorie-free, they cause insulin to be released in your gut because their artificial sweeteners are sweet like sugar, and that actually prevents weight loss," says Jacobson. "Insulin is your body's primary fat-storage hormone, so it will have the body hold on to any extra fat," she explains, adding that, "Trying to lose weight by trading a Coke for this is doing the body just as much harm, if not more, because of all the chemicals in the calorie-free version."
Flavored Diet Coke
12 fl oz: 0 calories, 0 g carbs (0 g sugar)
Ingredients: Carbonated Water, Less Than 0.5% of: Natural Flavors, Caramel Color, Phosphoric Acid, Aspartame, Acesulfame Potassium, Potassium Benzoate, Potassium Citrate, Caffeine
Diet Coke decided to change things up in 2018 with the introduction of four calorie-free flavors: Feisty Cherry and Ginger Lime, a bold change made to modernize the brand. While the flavors sound nothing but fun and fruity, their ingredient lists are full of additives. You're better off sipping on one of these healthy soda alternatives that will make it easy to quit soda.
Ingredients: Carbonated Water, Caramel Color, Aspartame, Phosphoric Acid, Potassium Benzoate, Natural Flavors, Citric Acid, Caffeine
The best-selling diet soda in the world still has a rather lackluster ingredient list, no matter how you spin it.
Diet Coke With Splenda
Ingredients: Carbonated Water, Caramel Color, Aspartame, Phosphoric Acid, Potassium Benzoate, Sucralose, Caffeine, Acefulsame Potassium, Citric Acid, Tartaric Acid
After reviewing more than 110 animal and human studies, the FDA decided in 1999 to approve sucralose, aka Splenda, for use in all foods. Sucralose opponents argue that the amount of human research is inadequate, but even groups like the Center for Science in the Public Interest have deemed it safe. Too bad this one's a bit hard to find.
Ingredients: Carbonated Water, Caramel Color, Aspartame, Phosphoric Acid, Potassium Benzoate (Preserves Freshness), Caffeine, Citric Acid, Natural Flavor, Acesulfame Potassium
Pepsi axed aspartame in its formula back in 2015, replacing it with Ace-K and sucralose. But when former fans demanded the return of the original recipe, the brand acquiesced and injected the sweetener back into the cans.
Caffeine-Free Diet Coke
Ingredients: Carbonated Water, Caramel Color, Aspartame, Phosphoric Acid, Potassium Benzoate, Natural Flavors, Citric Acid
Although we're not against caffeine—it's proven to boost metabolism and aid weight loss—excessive caffeine messes with your sleep schedule and suppresses functions of key immune agents. And insufficient sleep opens the door to colds, upper respiratory infections and other ills. So if you're on your third can of DC for the day, switch to this, if you must.
Caffeine-Free Diet Pepsi
Ingredients: Carbonated Water, Caramel Color, Phosphoric Acid, Potassium Benzoate (Preserves Freshness), Citric Acid, Natural Flavor, Acesulfame Potassium, Potassium
As we've said, we're into caffeine, as long as you don't overdo it. But why drink a can of chemicals if you're not even benefiting from the buzz?
7Up Zero Sugar
Ingredients: Filtered Carbonated Water, Citric Acid, Potassium Citrate, Potassium Benzoate (Preservative), Aspartame, Acesulfame Potassium, Natural Flavors, Calcium Disodium EDTA
What separates this from all the rest? No artificial coloring. Yet it's still filled with artificial sweetener. Many of the unhealthiest foods on the planet contain this metabolism-disrupting ingredient!
Ingredients: Carbonated Water, Citric Acid, Potassium Citrate, Natural Flavors, Potassium Benzoate, Aspartame, Acesulfame Potassium
As with the Diet 7Up, the Sprite Zero has no artificial colors. But why settle for artificial flavors?
Zevia Ginger Root Beer
Ingredients: Carbonated Water, Stevia Leaf Extract, Natural Flavors, Citric Acid
This small company, founded by soda-loving parents who wanted something healthier for their children, distributes a variety of classic flavors from cola to ginger ale to grape without using artificial sweeteners or artificial colors. Instead, they're sweetened with stevia.
"Unlike other sweeteners—specifically artificial sweeteners—they are not thousands of times sweeter than sugar, so they may cause less metabolic confusion in terms of sweetness as compared to caloric delivery, although more research still needed," Smith tells us. Brilliantly, this root beer tastes like the real thing—and is clear, because there's no caramel color.
16 fl oz: 0 calories, 0 g carbs (0 g sugar)
Ingredients (Black Raspberry): Purified Water, Black Raspberry, Other Natural Flavors from non-GMO Plants and Natural Caffeine from Coffee Beans
OK, we're totally cheating here. Hint Water isn't carbonated, cola-flavored, or sold in 64-ounce Big Gulps. But these flavored bottled waters do have 60 milligrams of caffeine derived from coffee beans. That's more than you'll find in Diet Dr. Pepper (41 milligrams), Diet Coke (47 milligrams), or even Mountain Dew (54 milligrams). So you get all of the pop, with none of the calories—and each flavor is sweetened not with aspartame, but with fruit juice or spice. Try the Black Raspberry (and don't overdo it, since caffeine can dehydrate you), and you'll never go back to Diet Coke again.
Ingredients: Filtered Carbonated Water, Bai Proprietary Sweetener Blend (Erythritol, Stevia Extract), Natural Flavors, Cherry Juice Concentrate, Malic Acid, Citric Acid, Fruit and Vegetable Juice (for color), Coffeefruit Extract, White Tea Extract, Ascorbic Acid, Sodium Citrate.
Founded by coffee guru Ben Weiss in his Princeton basement, Bai5 is a line of all-natural fruity drinks with exotic flavors like Guatemala Guava, Jamaica Blood Orange, and Bolivia Black Cherry. They're sweetened with fruit juice, erythritol, and stevia (not aspartame) and powered by 45 milligrams of caffeine, thanks to the tea and coffeefruit. This one diet soda you can sip on and not be as worried!