Can I drink Pepsi instead of water?

January 10, 2026 •

3 min read

According to the USDA, a standard 12-ounce can of Pepsi contains roughly 9 teaspoons of added sugar, providing empty calories with no nutritional benefit. This fact alone highlights the stark health differences between this sugary beverage and plain water.

Quick Summary

Replacing water with Pepsi is detrimental to health, increasing risks of obesity, diabetes, and dental erosion. Water is the only truly healthy beverage for complete hydration and bodily functions, lacking the sugar, acid, and caffeine of soda.

Key Points

Pepsi is not a substitute for water: Despite being mostly water, the high sugar, caffeine, and acid content makes it unsuitable for healthy hydration.
Significant health risks exist: Consistently choosing Pepsi over water dramatically increases the risk of obesity, Type 2 diabetes, heart disease, and dental decay.
Pepsi offers empty calories: A single can contains excessive sugar and calories with no nutritional benefits, unlike water which is essential for bodily functions.
Caffeine can have a diuretic effect: The caffeine in Pepsi can increase urination, which can lead to a net loss of fluid in the body over time.
Healthier alternatives are available: For those who crave the taste and fizz, opting for seltzer, flavored sparkling water, or fruit-infused water is a much better choice.

Water vs. Pepsi: The Fundamental Difference

While soda is primarily composed of water, the additional ingredients fundamentally change its effect on the body, making it a poor substitute for pure water. Regular Pepsi is loaded with high-fructose corn syrup, artificial flavors, and phosphoric acid, which create a drastically different nutritional profile. Water, on the other hand, is a simple, calorie-free fluid essential for life, performing crucial functions such as regulating body temperature, lubricating joints, and transporting nutrients. The key takeaway is that the 'hydration' from Pepsi comes with a heavy baggage of negative health consequences.

The Immediate Health Impacts

Consuming Pepsi instead of water leads to immediate and noticeable effects on the body. The high sugar content causes a rapid spike in blood sugar, followed by a crash that can leave you feeling tired and craving more sugar. Caffeine, another component in cola drinks, acts as a diuretic, which can increase urination and, in some cases, lead to fluid loss, undermining its own hydrating properties. The carbonation and high acidity can also cause gastric irritation, bloating, and digestive discomfort for some individuals.

The Long-Term Consequences of Swapping Water for Soda

Over time, making Pepsi your primary source of hydration can lead to severe and chronic health problems. The excessive sugar intake is directly linked to increased risks of:

Obesity and weight gain
Type 2 diabetes due to insulin resistance
Heart disease and high cholesterol
Non-alcoholic liver disease
Kidney problems, including kidney stones
Dental decay and erosion of tooth enamel due to sugar and acid

Water vs. Pepsi: A Nutritional Comparison


Feature	Water	Pepsi (Regular)
Calories	0	~155 per 12 oz can
Sugar	0	~41g per 12 oz can
Caffeine	0	~38mg per 12 oz can
Acidity (pH)	Neutral (~7)	Highly Acidic (~2.5)
Nutritional Value	Essential for bodily functions	None (empty calories)
Hydration Effect	Optimal	Sub-optimal, offset by diuretics and sugar
Dental Health	Beneficial	Highly damaging due to sugar and acid

Healthier Alternatives to Pepsi

If you find yourself craving the fizz and taste of soda, there are much healthier ways to satisfy that urge without the negative side effects. Switching gradually can help your taste buds adjust away from the intense sweetness.

Flavored Seltzer or Sparkling Water: Provides the bubbles and can be enhanced with fruit slices for flavor without the sugar or artificial sweeteners.
Unsweetened Iced Tea: A low-calorie option that offers variety.
Water with Fruit Infusions: Adding slices of cucumber, lemon, lime, or berries to water can make it more interesting.
Kombucha: A fermented tea that offers a fizzy tang with probiotic benefits, though some brands can contain sugar.

The Psychological Aspect of Soda Consumption

Beyond the physical toll, relying on soda can also form a powerful habit, fueled by the addictive nature of both sugar and caffeine. The dopamine release in the brain from sugar intake creates a reward-seeking cycle that can be difficult to break. By consciously choosing healthier alternatives, you can retrain your palate and your brain to appreciate more wholesome sources of hydration.

Conclusion

While a can of Pepsi can technically contribute a small amount of fluid, it is not a suitable or healthy replacement for water. The high levels of sugar, calories, caffeine, and acid pose immediate and long-term risks to your dental, metabolic, and cardiovascular health. For true hydration and overall well-being, water remains the best, most essential choice. The transition from soda to water, while challenging at first, is one of the most beneficial changes you can make for your health. To explore the broader impact of sugar-sweetened beverages on health, read more from the Centers for Disease Control and Prevention (CDC).

Frequently Asked Questions

Yes, Pepsi is primarily water, and that fluid does technically count toward your intake. However, the high sugar and caffeine content effectively counteracts the hydrating benefits, making it a poor choice.

While diet Pepsi is calorie and sugar-free, research suggests that artificial sweeteners can still have negative effects on the gut microbiome, insulin sensitivity, and can increase cravings for sweet foods. Water is always the healthier option.

Yes. The caffeine in soda is a mild diuretic that promotes fluid loss through urination. The high sugar content can also draw water from the body during metabolism, making it less hydrating than pure water.

The high acidity and sugar content in Pepsi can severely damage tooth enamel. The acid erodes the enamel, while the sugar feeds bacteria that produce more acid, leading to cavities and decay.

Pepsi is a source of empty calories and added sugar. Liquid calories are less filling than solid food calories, so you're more likely to consume more total calories without feeling full, contributing to weight gain.

Switching from soda to water can lead to multiple health benefits, including weight loss, improved metabolism, better dental health, clearer skin, and reduced risk of chronic diseases like diabetes and heart disease.

Experts recommend limiting soda intake as much as possible due to the significant health risks. For optimal health and hydration, water should be the primary beverage choice.