Nutrition Diet: What's the Unhealthiest Soda to Drink?

October 8, 2025 •

4 min read

Studies have shown that regular consumption of sugary beverages significantly increases the risk of developing conditions like type 2 diabetes and metabolic syndrome. Given these severe health concerns, many people are driven to ask: What's the unhealthiest soda to drink?

Quick Summary

While all sugary soft drinks are harmful, Mountain Dew is consistently highlighted as a top contender for the unhealthiest due to its exceptionally high sugar and acid content, along with problematic artificial additives.

Key Points

Mountain Dew is exceptionally unhealthy: Due to its very high sugar content, high acidity from citric acid, and historical use of additives like BVO, it's a top contender for the unhealthiest soda.
Excessive sugar leads to major health issues: High-fructose corn syrup in regular sodas contributes to weight gain, type 2 diabetes, and fatty liver disease.
Acid erodes tooth enamel: The phosphoric and citric acids in both regular and diet sodas can lead to significant dental decay and erosion.
Diet sodas have their own risks: Artificial sweeteners may impact gut health, increase cravings, and are still highly acidic, challenging their reputation as a healthy alternative.
Energy drinks are potent and risky: These beverages combine excessive sugar and stimulants like caffeine, posing serious risks to heart and metabolic health.
Healthier alternatives exist: Sparkling water, kombucha, and naturally flavored teas are excellent replacements for soda that provide flavor without the harmful additives.

The Core Culprits: What Makes a Soda Unhealthy?

To understand what's the unhealthiest soda to drink, one must look beyond just calories and examine the key ingredients that drive negative health outcomes. The primary concerns in most soft drinks revolve around high sugar levels, damaging acids, and a cocktail of artificial additives.

Excessive Added Sugar

The most common and detrimental ingredient in soda is added sugar, often in the form of high-fructose corn syrup (HFCS). Regular sodas are notorious for containing sugar levels that far exceed daily recommendations in a single serving. Excessive sugar intake is directly linked to:

Weight Gain and Obesity: Sugary drinks are a source of "empty calories" that do not produce the same feeling of fullness as solid food, leading to overconsumption.
Type 2 Diabetes: The rapid and consistent blood sugar spikes from liquid sugar can cause insulin resistance over time.
Nonalcoholic Fatty Liver Disease: The liver metabolizes fructose from HFCS, and an overload can lead to fat accumulation in the liver.

Damaging Acids

Sodas contain a high level of acidity from ingredients like phosphoric acid and citric acid, which can be harmful to dental health even in diet versions.

Tooth Decay and Enamel Erosion: The high acidity softens tooth enamel, making it more vulnerable to erosion and decay. When combined with sugar, it provides a perfect breeding ground for cavity-causing bacteria.
Bone Health: Some research suggests that the phosphoric acid in cola may interfere with calcium absorption and lead to lower bone mineral density, particularly in women.

Artificial Additives

Beyond sugar and acid, some sodas contain other questionable additives that contribute to their unhealthy profile. These include artificial colors like Yellow 5 and preservatives like sodium benzoate. Certain beverages, specifically citrus-flavored ones, historically contained brominated vegetable oil (BVO), an emulsifier linked to neurological issues that is banned in Europe and now being phased out in the U.S.

The Top Contenders for Unhealthiest Soda

Based on a combination of extreme sugar content, high acidity, and specific concerning additives, certain sodas consistently top the list of the most unhealthy choices.

Mountain Dew

Mountain Dew is frequently singled out as one of the worst offenders for several reasons:

Highest Sugar Content: A 12-ounce can contains more sugar than a similar-sized can of Coke, leading to more significant blood sugar spikes.
Unique Dental Damage: Its citric acid content, which is different from cola's phosphoric acid, can be particularly erosive and aggressive toward tooth enamel.
Controversial Additives: Mountain Dew has historically contained artificial dyes like Yellow 5 and, until recently, BVO.

Energy Drinks

While not always classified as traditional soda, energy drinks share similar traits and are arguably even worse. Brands like Rockstar often combine excessive amounts of sugar with high levels of caffeine and other stimulants. The extremely high doses of both can cause jitters, sleep disturbances, and increased heart rate, making them dangerous for sensitive individuals.

High-Sugar Fruit Sodas

Brightly colored, fruit-flavored sodas like Fanta Orange are often loaded with artificial dyes and HFCS, offering little to no nutritional value. Despite their fruity branding, these beverages are just as detrimental as colas due to their high sugar content and artificial nature.

Diet vs. Regular Soda: The Lesser of Two Evils?

For years, diet soda was promoted as a healthier alternative due to its zero-calorie, zero-sugar nature. However, it presents its own set of concerns.

Artificial Sweeteners: Many diet sodas contain artificial sweeteners like aspartame, sucralose, and acesulfame potassium. While these are approved by regulatory bodies, research has linked them to altered gut microbiota, increased cravings, and metabolic dysfunction. The World Health Organization even classified aspartame as a possible carcinogen.
Dental Erosion: Diet sodas are still highly acidic and contribute to dental enamel erosion, even without the sugar.

The Unhealthy Soda Comparison Table


Beverage (12 oz)	Calories	Sugar (grams)	Acid Content	Notable Additives	Primary Health Concerns
Mountain Dew	170	46	Citric Acid	Yellow 5, HFCS	Dental erosion, high sugar load, artificial dyes
Rockstar Energy	~160	~63 (per 16 oz)	Citric Acid	Excessive Caffeine, Taurine, Guarana, HFCS	Heart rate, blood pressure, sugar overload
Coca-Cola Classic	140	39	Phosphoric Acid	Caramel Coloring, HFCS	Sugar load, dental decay, bone density issues
Fanta Orange	~195 (per 16.9 oz)	44 (per 20 oz)	Citric Acid	Artificial dyes (Yellow 6, Red 40), HFCS	High sugar, artificial dyes
Diet Coke	0	0	Phosphoric Acid	Aspartame, Caramel Coloring	Artificial sweeteners, dental erosion

Healthier Hydration Alternatives

Quitting soda doesn't mean giving up satisfying beverages. There are many healthier and flavorful alternatives to consider:

Sparkling Water: Offers the fizz of soda without the sugar or artificial sweeteners. Infusing with fruits like lemon, lime, or cucumber adds natural flavor.
Kombucha: This fermented tea contains probiotics that are beneficial for gut health. Look for low-sugar varieties.
Herbal Iced Tea: Unsweetened or lightly sweetened with natural low-calorie options like stevia can provide flavor and caffeine (if desired) without the negative effects of soda.
Water with a Splash of Juice: A small amount of 100% fruit juice added to sparkling water provides a fruity taste with far less sugar than a full-strength fruit drink.
Prebiotic Sodas: Brands like Poppi or OLIPOP offer a soda-like experience with lower sugar and added prebiotics for gut health.

Conclusion

While a definitive single "unhealthiest" soda is debatable and depends on individual health factors, most nutritional experts point to Mountain Dew as a primary offender. Its extreme combination of sugar, high acidity, and concerning artificial additives creates a trifecta of harm, especially for dental and metabolic health. Furthermore, relying on diet soda is not a guilt-free escape, as artificial sweeteners carry their own set of health risks. Ultimately, the healthiest approach is to replace sugary and artificially sweetened sodas with water, unsweetened tea, or naturally flavored sparkling water. By prioritizing these healthier hydration options, you can significantly reduce your risk of chronic diseases and improve your overall well-being. For more insights on healthier dietary choices, explore authoritative resources like the American Heart Association's guidelines on added sugars.

Frequently Asked Questions

Mountain Dew is consistently found to be among the highest in sugar content, with a 12-ounce can containing significantly more sugar than a can of Coca-Cola.

While diet soda has no calories or sugar, it is not necessarily a healthy alternative. It still contains acids that harm teeth and artificial sweeteners with potential negative effects on gut health and metabolism.

High-fructose corn syrup is a cheaper, highly processed sweetener used in many sodas. The high fructose concentration is processed differently by the liver and has been linked to obesity, type 2 diabetes, and fatty liver disease.

The combination of high sugar and high acidity in soda creates a perfect storm for dental damage. The acid erodes enamel, and the sugar feeds bacteria that produce more acid, leading to cavities and tooth decay.

Historically, many citrus-flavored sodas, including Mountain Dew and Fanta, contained BVO as an emulsifier. Due to health concerns, many companies, including PepsiCo and Coca-Cola, have pledged to remove it.

Studies have shown an association between cola consumption, particularly the phosphoric acid it contains, and lower bone mineral density in women, potentially by interfering with calcium absorption.

Excellent healthy alternatives include sparkling water (plain or infused with fruit), kombucha, unsweetened iced tea, or prebiotic sodas from brands like Poppi.

Energy drinks are often grouped with soda but can be even more harmful due to their excessive levels of both sugar and stimulants like caffeine, which pose additional cardiovascular risks.