Mountain Dew is higher in calories, sugar, and caffeine than Coca-Cola, and it contains additives that Coke doesn’t. But Coca-Cola is actually more acidic, which matters for your teeth. Neither drink is a healthy choice, but the differences between them are real and worth understanding if you’re deciding between the two or cutting back on one.
Calories and Sugar
A 12-ounce can of Mountain Dew has 174 calories, while the same size Coca-Cola Classic has 155 calories. That 19-calorie gap might sound small, but it adds up over daily or weekly consumption. Both drinks get virtually all their calories from sugar.
Federal dietary guidelines recommend that added sugars make up less than 10% of your total daily calories. On a standard 2,000-calorie diet, that’s about 200 calories from added sugar per day, or roughly 12 teaspoons. A single can of Mountain Dew burns through 87% of that limit. A Coke uses up about 78%. Either way, one can leaves almost no room for added sugar from anything else you eat or drink that day.
Both drinks are sweetened with high-fructose corn syrup, and the fructose content may be higher than you’d expect. Researchers at the University of Southern California’s Keck School of Medicine analyzed popular sodas including Coca-Cola, Mountain Dew, and others made with HFCS. They found the actual fructose-to-glucose ratio was closer to 60:40, meaning 50% more fructose than glucose. That matters because your liver processes fructose differently than other sugars, and high fructose intake is linked to fatty liver disease and metabolic problems.
Caffeine Content
Mountain Dew contains 54 mg of caffeine per 12-ounce can. Coca-Cola has 34 mg in the same serving. That makes Mountain Dew roughly 60% higher in caffeine. Zero Sugar Mountain Dew pushes even higher, to 68 mg per can.
For context, a standard cup of brewed coffee has about 95 mg. So neither soda is an extreme caffeine source, but the difference between them is meaningful if you’re sensitive to caffeine, drinking multiple cans, or giving soda to kids. Diet Coke, interestingly, has more caffeine than regular Coke at 46 mg per can.
Which One Is Worse for Your Teeth
This is where the comparison gets interesting, because Coca-Cola actually wins the “worse” title. Tooth enamel starts to break down when exposed to liquids below a pH of 5.5, and both sodas fall well below that threshold. But Coca-Cola Classic has a pH of 2.37, while regular Mountain Dew comes in at 3.22.
That difference is more significant than it looks. The pH scale is logarithmic, so a drop of one full unit from pH 3.0 to 2.0 represents roughly a tenfold increase in how readily the drink dissolves tooth enamel. Dental researchers classify beverages below pH 3.0 as “extremely erosive” and those between 3.0 and 3.99 as “erosive.” Coca-Cola falls squarely in the extremely erosive zone, while regular Mountain Dew sits just above that line in the erosive category.
The acids responsible are different too. Coca-Cola relies on phosphoric acid for its tangy bite. Mountain Dew uses citric acid, which gives it that citrus flavor. Both erode enamel, but the lower pH of Coke means it has greater immediate erosive potential on contact with your teeth. If dental health is your primary concern, Coke is technically the harsher drink.
Artificial Colors and Additives
Mountain Dew gets its yellow-green color from Yellow 5 (tartrazine), a synthetic dye that has drawn more scrutiny than most food colorings. It’s associated with allergic reactions, particularly in people with asthma or aspirin sensitivity. A well-known study found that exposure to a mixture including tartrazine increased hyperactivity in children aged 3 and 8 to 9. It’s also been linked to hives and swelling of the lips, tongue, and throat in sensitive individuals.
Coca-Cola uses caramel color, which carries its own concerns. The main issue is a chemical called 4-methylimidazole, a byproduct of how caramel color is manufactured. Animal studies have flagged it as a potential problem at high doses, with effects on white blood cell counts and possible gastrointestinal issues. The risks at the levels found in a can of soda are debated, but neither coloring agent is something your body needs.
Brominated Vegetable Oil
Mountain Dew historically contained brominated vegetable oil (BVO), a stabilizer used to keep citrus flavoring evenly mixed. PepsiCo removed BVO from Mountain Dew around 2020, and the FDA has since revoked BVO’s authorization as a food ingredient entirely. The agency cited evidence that bromine accumulates in the body at all exposure levels tested and causes thyroid damage in animal studies. The ban takes full effect in 2026, giving remaining manufacturers time to reformulate. This is no longer a difference between the two drinks, but it’s part of Mountain Dew’s history that shaped its reputation.
The Overall Comparison
Here’s how the two stack up in a 12-ounce can:
- Calories: Mountain Dew 174, Coca-Cola 155
- Caffeine: Mountain Dew 54 mg, Coca-Cola 34 mg
- pH (acidity): Mountain Dew 3.22, Coca-Cola 2.37
- Coloring: Mountain Dew uses Yellow 5, Coca-Cola uses caramel color
- Sweetener: Both use high-fructose corn syrup with a roughly 60:40 fructose-to-glucose ratio
Mountain Dew delivers more calories, more sugar, and more caffeine per can. It also contains a food dye with a longer list of documented sensitivities. Coca-Cola, on the other hand, is significantly more acidic and does more immediate damage to tooth enamel on contact. Neither drink offers any nutritional benefit.
If you’re choosing between the two, Mountain Dew is the slightly worse option by most nutritional measures. It gives you more of the things you’re trying to limit (sugar, calories, caffeine) in every serving. But the real gap between them is smaller than the gap between either soda and water, unsweetened tea, or any other zero-sugar drink. Swapping one soda for the other isn’t a meaningful health improvement. Drinking less of either one is.