Does Whole Milk Count Towards Water Intake?

November 27, 2025 •

3 min read

According to the USDA, whole milk is composed of approximately 87-88% water, meaning a significant portion of a glass of milk is pure fluid. This fact confirms that whole milk counts towards water intake, but the story is more complex due to its unique nutritional profile that affects how the body absorbs and retains that fluid.

Quick Summary

Whole milk contributes to daily fluid intake because it is mostly water, but its electrolytes, protein, and fat slow absorption and retention for potentially better, more sustained hydration than plain water, especially post-exercise.

Key Points

Water Content: Whole milk is approximately 87-88% water, so a glass contributes a significant amount of fluid to your daily intake.
Superior Retention: Due to its protein, fat, and electrolytes, milk hydrates more effectively over a longer period than plain water by slowing fluid from leaving the stomach.
Post-Workout Recovery: Milk's combination of fluid, carbohydrates, protein, and electrolytes makes it an excellent recovery drink, helping to replenish what's lost during strenuous exercise.
Nutrient-Dense Hydration: Unlike plain water, milk provides a range of essential nutrients and calories, which is beneficial for overall health but must be considered for daily caloric goals.
Not a Water Replacement: While milk is hydrating, water should remain the primary beverage for daily hydration due to its lack of calories and its efficient absorption for immediate needs.
Electrolyte Benefits: The sodium and potassium naturally present in milk help maintain the body's fluid balance, supporting nerve and muscle function.

Understanding Hydration Beyond Plain Water

For most people, the concept of hydration revolves around drinking plain water. While water is undoubtedly the ideal zero-calorie fluid source, it is not the only beverage that contributes to overall hydration. The reality is that the body draws fluid from all types of beverages and even foods that contain water, including milk. The effectiveness of a fluid for hydration, however, depends on its composition of macronutrients and electrolytes, which influence the rate of absorption and fluid retention.

The Science of Milk and Hydration

Whole milk's hydrating power comes from a potent combination of its water content and other naturally occurring components. A glass of whole milk is roughly 88% water. This high liquid percentage is combined with a unique mix of macronutrients and electrolytes that influence how the body handles the fluid. Studies have shown that the natural sugar (lactose), protein, and fat in milk slow down the rate at which fluid leaves the stomach. This delayed gastric emptying means the fluid is absorbed more gradually, leading to less immediate urination and better fluid retention over a longer period. Additionally, milk's electrolytes, such as sodium and potassium, are critical for maintaining fluid balance in the body, which further enhances its rehydration capabilities.

How Whole Milk Compares to Other Beverages

Recent research has even suggested that milk can be more hydrating than plain water in certain scenarios. A 2016 study published in The American Journal of Clinical Nutrition developed a Beverage Hydration Index (BHI) to compare the hydrating effects of different drinks. The study found that both full-fat and skim milk ranked higher than plain water in terms of maintaining fluid balance. This is not a reason to replace all water with milk, but it illustrates milk's effectiveness as a hydrating beverage, especially in specific situations like post-exercise recovery.

Whole Milk vs. Other Milk Varieties and Fluids

Different milk types and beverages offer varying hydration benefits. While all milks are primarily water, their nutritional composition affects their hydrating properties. Whole milk, with its higher fat content, provides a more energy-dense rehydration option.


Feature	Whole Milk	Skim Milk	Sports Drink	Plain Water
Water Content	~88%	~90%	>90%	100%
Key Hydration Factor	Electrolytes, Protein, Fat	Electrolytes, Protein	Electrolytes, Sugar	Zero Calories
Best For	Post-intense exercise recovery where energy is needed	Daily hydration for those watching calories; post-exercise	Replenishing carbohydrates and electrolytes during prolonged exercise	Regular, daily hydration with no added calories
Retention Period	Longer duration due to fat and protein slowing absorption	Longer duration than water due to electrolytes and protein	Intermediate; depends on sugar concentration	Quick hydration; no retention-slowing components
Calorie Count	High	Low	Varies; can be high	Zero

How to Incorporate Milk into Your Hydration Strategy

Adding milk to your routine can be an effective way to meet fluid goals and gain valuable nutrients, but it's important to do so in balance. For most daily needs, plain water is still the best and most calorie-efficient choice. However, whole milk's unique nutrient profile makes it particularly useful for rehydration after moderate to intense exercise. The protein helps with muscle repair, and the carbohydrates replenish energy stores, making it a functional recovery drink. For children or individuals who may not be eating enough, milk can be a source of both fluid and nutrients. The key is to see milk as part of your total fluid intake, not a replacement for water.

Conclusion: Whole Milk's Role in Fluid Balance

In conclusion, does whole milk count towards water intake? The answer is an unequivocal yes, and it may even provide superior, longer-lasting hydration than plain water in specific situations. Whole milk contains a high percentage of water, along with electrolytes, carbohydrates, protein, and fat that work together to slow fluid absorption and improve retention in the body. While water should remain the cornerstone of your daily hydration, especially for general purpose needs, a glass of whole milk can be a powerful and nutritious rehydration tool after a strenuous workout or as part of a balanced diet. Individuals with dietary restrictions like lactose intolerance, however, should consider fortified alternatives to get similar nutritional benefits.

Disclaimer

The information in this article is for informational purposes only and does not constitute medical advice. Consult a healthcare professional or registered dietitian for personalized advice regarding your dietary and hydration needs.

Frequently Asked Questions

No, you should not replace all your water intake with whole milk. While milk is hydrating and nutritious, it is also calorie-dense. Drinking enough milk to meet all fluid requirements would lead to excessive calorie consumption and potentially unwanted weight gain.

Studies show that both whole and skim milk are more hydrating than water over a longer period. While skim milk has a slightly higher water content, whole milk's additional fat and protein can slow gastric emptying even further, promoting sustained hydration.

Milk often proves superior for rehydration after exercise because it provides a better balance of protein, carbohydrates, and electrolytes. Traditional sports drinks focus primarily on replenishing carbs and some electrolytes, while milk offers a more comprehensive recovery package.

Yes, whole milk can help with mild dehydration by replenishing both fluids and electrolytes. However, for severe dehydration, an oral rehydration solution formulated to restore fluid balance quickly is more appropriate.

Plant-based milks, such as almond or soy, contain high percentages of water and contribute to hydration. However, most lack the natural balance of electrolytes and macronutrients found in cow's milk, which contribute to better fluid retention.

The primary reason milk hydrates so well is the presence of electrolytes like sodium and potassium, along with protein and fat. These components help the body absorb water more efficiently and retain it for longer by slowing down its passage through the digestive system.

The best way to use whole milk for hydration is strategically, such as a post-workout recovery drink. For general, daily hydration needs, stick primarily to water, but know that a glass of milk is a nutritious and effective way to contribute to your overall fluid intake.