Does Milk Give More Hydration Than Water? The Surprising Truth

October 19, 2025 •

2 min read

According to a 2016 study published in the American Journal of Clinical Nutrition, both skim and whole milk were found to be more hydrating than plain water over a four-hour period. The research revealed a surprising truth about whether or not does milk give more hydration than water, challenging conventional wisdom and highlighting milk's unique composition for fluid retention.

Quick Summary

Studies show milk can offer more prolonged hydration than water due to its nutrient content, which slows digestion and promotes fluid retention. While water is ideal for daily intake, milk's electrolytes, carbs, and protein make it particularly effective for rehydration after intense exercise.

Key Points

Milk contains electrolytes: Sodium and potassium in milk help the body retain fluids more effectively than water.
Nutrients slow fluid absorption: Protein, fat, and lactose in milk delay gastric emptying, leading to slower, more prolonged hydration.
Water is ideal for daily hydration: For general, low-calorie hydration needs, plain water remains the best and most practical choice.
Milk excels for post-exercise recovery: After an intense workout, milk replenishes lost electrolytes, fluids, and muscle glycogen more efficiently than water.
Consider the calories: Milk adds calories to your diet, so it is not a suitable substitute for water for consistent, everyday fluid intake.

The Science Behind Milk's Superior Hydration

While water is the standard for hydration, research into the body's fluid retention mechanisms has shown that milk often ranks higher on the "Beverage Hydration Index" (BHI). This is because milk contains electrolytes, carbohydrates, and proteins that are not found in plain water.

The Role of Electrolytes and Nutrients

Water passes through the digestive system quickly, but milk's electrolytes like sodium and potassium help the body hold onto fluid, leading to less urine production. The carbohydrates and proteins in milk slow down digestion, allowing for more gradual and sustained fluid absorption.

Milk for Post-Exercise Recovery

Milk's ability to retain fluid and replace electrolytes makes it particularly beneficial after strenuous exercise. It helps restore fluid balance and provides nutrients for muscle recovery, making it a popular choice for athletes.

Comparison: Milk vs. Water for Hydration

For most daily hydration needs, water is the best choice due to its lack of calories and accessibility. However, milk offers advantages in specific situations.


Feature	Water	Milk (Cow's)
Primary Hydration Benefit	Fast, immediate fluid replenishment.	Slower, more sustained fluid retention.
Nutrient Content	None (unless fortified with minerals).	Electrolytes (Sodium, Potassium), Protein, Carbs, Fat.
Caloric Content	0 calories.	Varies by type, can be high (e.g., whole milk).
Best for Daily Use	Yes, ideal for continuous, low-calorie hydration.	No, not ideal for primary daily hydration due to calories.
Best for Post-Workout	Acceptable for light workouts.	Superior for intense, sweaty workouts and muscle recovery.
Fluid Retention	Exits the body relatively quickly.	Nutrients slow gastric emptying, retaining fluid longer.

Water: The Everyday Hydration Staple

Water is the recommended first choice for daily hydration because it is calorie-free and essential for normal bodily functions. Drinking milk as the primary source of hydration is generally not recommended due to its caloric content.

Other Factors Affecting Hydration

Other factors impact hydration, including physical activity and health. Beverages high in sugar or alcohol can be less hydrating.

Conclusion: Finding the Right Drink for the Job

Scientific research supports the idea that milk can be more hydrating than water for sustained fluid retention, especially after dehydration. However, water remains the best option for everyday hydration. Milk is a strategic choice for post-workout recovery when nutrient replenishment is needed. The best drink depends on your specific hydration needs.

For more detailed research, refer to the study: A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index.

Frequently Asked Questions

Yes, in certain situations. Studies have shown milk can provide more prolonged hydration than water because its nutrient content (electrolytes, protein, fat) slows fluid absorption, helping the body retain fluid for longer.

Water is the best choice for everyday hydration because it contains no calories, is widely available, and is essential for all bodily functions. Milk's caloric density makes it unsuitable as a primary, constant source of fluids.

Both skim and whole milk have been shown to be more hydrating than water. The difference in fluid retention between them is not significant, but low-fat milk offers the hydrating benefits with fewer calories.

While chocolate milk is an effective recovery drink due to its carbs, protein, and electrolytes, it is not significantly more hydrating than plain milk. For hydration purposes, plain milk is sufficient.

Milk is particularly beneficial for rehydration after an intense and sweaty workout. It helps replenish lost fluids, electrolytes, and provides nutrients for muscle recovery.

No, beverages high in concentrated sugar are generally less hydrating than water. The high sugar content can pull water from the body into the small intestine, counteracting hydration.

Plant-based milks like almond or soy milk have a high water content but typically lack the same balance of electrolytes, carbohydrates, and protein as cow's milk. While they contribute to hydration, their overall fluid retention effect may be less pronounced.