Is a zero-sugar drink healthier than a diet drink?

November 7, 2025 •

4 min read

While both labeled as diet-friendly, the health impacts of zero-sugar and diet drinks are relatively similar, often containing artificial sweeteners and offering no nutritional value. The key to understanding if a zero-sugar drink is healthier than a diet drink lies in examining their subtle differences in composition and potential health effects.

Quick Summary

This article explores the ingredients, artificial sweeteners, and potential health impacts of zero-sugar and diet drinks. It addresses the marketing differences and helps consumers understand that despite a name change, the core health concerns remain similar, emphasizing moderation and considering healthier alternatives.

Key Points

Limited Health Difference: There is minimal health distinction between 'diet' and 'zero-sugar' drinks, as both use artificial sweeteners and offer no nutritional benefits.
Artificial Sweeteners at Play: Common artificial sweeteners include aspartame and acesulfame potassium, which can potentially disrupt metabolism and increase cravings for sweet foods.
Potential Health Risks: Frequent consumption of both types of beverages is linked to health issues like metabolic syndrome, heart disease, gut microbiome disruption, and dental erosion.
Branding Over Nutrition: The labeling difference is often a marketing strategy to appeal to different consumer preferences, with 'zero-sugar' designed to taste more like the original.
Water is the Best Alternative: Experts recommend plain water as the healthiest choice, with other natural options like infused water or unsweetened tea also being far superior.
Moderation is Prudent: For those who choose to drink these beverages, it is important to do so in moderation and not rely on them as a daily hydration source.

What are diet drinks and zero-sugar drinks?

Diet and zero-sugar beverages are both formulated to offer a sweet taste without the calories of traditional sugary sodas. The primary difference often comes down to marketing and a slight variation in the blend of artificial sweeteners used to achieve a specific flavor profile. Brands like Coca-Cola and Pepsi have used these different labels to appeal to broader audiences, with 'zero-sugar' often aiming for a taste closer to the original full-sugar version. For instance, Diet Coke has a lighter taste, while Coca-Cola Zero Sugar is engineered to taste more like Classic Coke by using a blend of sweeteners. However, from a nutritional and health perspective, they are more alike than different.

The truth about artificial sweeteners

The zero-calorie status of both diet and zero-sugar drinks is due to the use of artificial sweeteners, which are far sweeter than sugar and contain virtually no calories. While considered safe for consumption by regulatory bodies like the FDA in moderation, the long-term health effects of these chemicals are a topic of ongoing research and debate.

Common culprits: The primary artificial sweeteners found in these drinks include aspartame, acesulfame potassium (Ace-K), and sometimes sucralose. Aspartame is common in diet drinks like Diet Coke, while zero-sugar versions often blend aspartame and Ace-K.
Metabolic response: Some research suggests that the intense sweetness without calories can confuse the brain, potentially increasing cravings for sweet, high-calorie foods and disrupting metabolic processes. This can paradoxically contribute to weight gain despite consuming zero-calorie beverages.
Gut health: Certain studies indicate that artificial sweeteners may negatively affect the balance of bacteria in the gut microbiome, which is crucial for digestive and metabolic health. A disrupted microbiome has been linked to potential issues with blood sugar control.

Potential health risks linked to sweetened drinks

Beyond metabolism and gut health, there are other potential health concerns associated with frequent consumption of diet and zero-sugar sodas.

Cardiovascular concerns: Observational studies have linked the consumption of artificially sweetened beverages to an increased risk of cardiovascular problems, including heart disease and high blood pressure. A World Health Organization review associated non-sugar sweeteners with an increased risk of type 2 diabetes and cardiovascular diseases.
Neurological effects: Aspartame, in particular, has been linked in some studies to neurological issues like headaches, mood disorders, and even an increased risk of stroke and dementia. More definitive research is needed, but the potential risks are a concern for some consumers.
Dental erosion: Both diet and zero-sugar sodas are often acidic, which can lead to the erosion of tooth enamel over time. This can cause increased tooth sensitivity and a higher risk of cavities.
Kidney health: High consumption of soda, regardless of sugar content, has been associated with an increased risk of chronic kidney disease.

Comparison table: Zero-sugar vs. diet drinks


Feature	Diet Drinks	Zero-Sugar Drinks	Health Considerations	Recommended Alternative
Sweeteners	Primarily aspartame	Blend of aspartame, acesulfame potassium, and sometimes other sweeteners	Both rely on artificial sweeteners with controversial long-term health effects.	Naturally sweetened alternatives (stevia, monk fruit)
Flavor Profile	Lighter, often with citrus notes	Designed to taste more like the full-sugar original	Flavor differences are purely preference; no health advantage to either.	Fruit-infused water
Calories	Zero	Zero	Calorie-free, but may disrupt metabolic processes and increase cravings.	Plain water
Nutritional Value	Zero	Zero	No vitamins, minerals, or other nutrients. Empty calories/sweetness.	Sparkling water with natural juices
Dental Impact	Highly acidic, causing tooth enamel erosion	Highly acidic, causing tooth enamel erosion	Both contribute to dental problems over time due to acidity.	Water or low-fat milk
Regulatory Status	FDA approved sweeteners for moderated use	FDA approved sweeteners for moderated use	Safe in small doses, but potential long-term risks are still under study.	Unsweetened tea or coffee

Are there healthier alternatives?

For those seeking to reduce their reliance on artificially sweetened drinks, several healthier alternatives can satisfy a craving for flavor without the associated risks.

Plain water: The most fundamental and best option for hydration, with zero calories, sugar, or additives.
Infused water: Add slices of lemon, cucumber, or berries to water for a natural flavor boost without extra calories or chemicals.
Unsweetened tea or coffee: These can be enjoyed hot or iced and offer natural flavors without added sugars or artificial sweeteners.
Sparkling water with natural juice: A splash of 100% fruit juice in sparkling water provides natural sweetness and flavor with less sugar than regular soda.
Naturally sweetened drinks: Some sodas use natural sweeteners like stevia or monk fruit. While often healthier, their effect on cravings and metabolism can still be a consideration.

Conclusion

When comparing a zero-sugar drink to a diet drink, the reality is that the health differences are negligible. Both rely on artificial sweeteners that, while approved for consumption, are associated with a range of potential health concerns, from metabolic disruption and increased cravings to negative effects on gut and cardiovascular health. The key distinction is often simply a branding choice and a subtle tweak to the flavor profile, not a significant health improvement. Experts, like those at the Cancer Council SA, advise against swapping sugary drinks for either diet or zero-sugar alternatives, recommending water and other naturally healthy options instead. For optimal health, the best approach is to reduce overall intake of both and focus on hydration from wholesome, natural sources.

Takeaways for informed drinking

Zero-sugar vs. diet: The terms often refer to similar products with negligible health differences; both use artificial sweeteners.
Artificial sweeteners: While FDA-approved, they are linked to potential long-term risks, including metabolic changes, increased cravings, and gut health issues.
Health concerns: Regular consumption of both diet and zero-sugar beverages is associated with risks like cardiovascular problems, neurological issues, and dental erosion.
Best choice: Plain water remains the healthiest option for hydration.
Natural alternatives: Infused water, unsweetened tea, or sparkling water with natural juice can provide flavor without the drawbacks.
Moderation is key: If you do consume diet or zero-sugar drinks, do so in moderation, not as a daily replacement for healthier options.

Frequently Asked Questions

The main difference between a zero-sugar and a diet drink is often a marketing and flavor profile distinction, not a significant nutritional one. Zero-sugar drinks are generally formulated to taste more like the original full-sugar version using a blend of artificial sweeteners, while diet drinks might have a lighter flavor from a different sweetener combination.

Not necessarily the exact same blend, but they both rely on artificial sweeteners. For example, Diet Coke traditionally uses only aspartame, while Coca-Cola Zero Sugar uses a mix of aspartame and acesulfame potassium (Ace-K). However, all these artificial sweeteners are generally associated with similar potential health concerns.

While zero-sugar and diet drinks are calorie-free, some studies suggest they may increase cravings for sweet, high-calorie foods, potentially leading to overeating and weight gain. The intense sweetness without the calories can disrupt the brain's hunger and satisfaction signals.

The safety of artificial sweeteners is still a subject of debate, although regulatory bodies generally consider them safe in moderation. However, concerns have been raised about potential links to metabolic syndrome, type 2 diabetes, and negative effects on the gut microbiome, with long-term effects still under investigation.

Neither is better for dental health, as both diet and zero-sugar sodas are highly acidic due to ingredients like phosphoric and citric acid. This acidity can erode tooth enamel over time, regardless of whether sugar is present.

Plain water is the healthiest beverage choice for hydration. Other excellent options include infused water with fruits or vegetables, unsweetened tea, or unsweetened coffee.

Swapping sugary drinks for diet or zero-sugar alternatives can reduce calorie intake, but experts caution against viewing them as a truly 'healthy' replacement. For optimal long-term health, the goal should be to reduce reliance on all sweetened beverages and transition to water.