Should You Drink Milk If You're Dehydrated?

Dehydration is a condition that occurs when too much fluid is lost from your body and not replenished.

Varying levels of dehydration exist, ranging from mild to severe. Severe dehydration is rare in the general, healthy population, while mild dehydration can be more common.

The main causes of dehydration include not drinking enough fluids, diarrhea, fever, and excessive sweating or urinating.

The most common signs of dehydration include (1):

• dry mouth or tongue
• thirst
• fatigue
• dry skin
• muscle weakness
• lack of focus
• dizziness

An accurate way to assess your hydration status is to have your doctor order labs to measure certain blood values, including sodium and potassium, which are the major electrolytes in your body involved with hydration (2).

That said, blood tests are typically not practical or available when looking to quickly assess your hydration status. Instead, the easiest way is to examine your urine color (3).

For most people, lemonade-colored urine reveals optimal hydration status, while darker, amber-colored urine indicates mild dehydration.

Summary

Severe dehydration is rare in the healthy population, though you may experience mild cases on occasion. The most practical method of determining your hydration status is to examine your urine color.

A 1-cup (240-mL) serving of whole cow’s milk contains (4, 5):

Milk is a decent source of sodium and potassium, the two major electrolytes in your body. These electrically charged minerals are important for maintaining hydration (2).

With 8 grams of protein per cup, milk is also a good source of protein, a nutrient that’s especially important when recovering from exercise (6).

Milk also provides carbohydrates, another important nutrient that may help prevent dehydration (7).

Lastly, given that whole milk provides 150 calories per cup, you may want to consider whether it fits your daily calorie needs before using it to quench your thirst on a regular basis.

Summary

Cow’s milk can be an appropriate beverage option for rehydration due to its electrolyte and carb content. In addition, it’s a good source of protein, making it a good exercise recovery drink.

If you believe you’re becoming dehydrated, it’s important to replenish your body’s fluid and electrolyte stores. For example, pay particular attention to your fluid and electrolyte intake during times of increased sweating.

This can be accomplished by drinking a variety of beverages or eating foods with a high water content.

Conveniently, milk may be a fitting beverage for rehydration due to its electrolyte content.

For example, a 2007 study in 11 healthy adults found low fat milk to be the beverage of choice for rehydration after mild exercise-induced dehydration, compared with water or a sports drink (8).

In addition, a 2015 study looking at the effects of 13 beverages on overall hydration status found milk to be comparable to an oral rehydration solution in terms of maintaining fluid balance (9).

However, this study looked at individuals with normal hydration status and therefore only applies to maintaining fluid balance — not treating dehydration. Meanwhile, data on the effectiveness of milk for treating more serious dehydration is limited.

Also, keep in mind that if you eat a nutritious, varied diet and consistently drink plenty of fluids, these efforts alone may be sufficient to maintain your fluid and electrolyte balance — even without adding milk to your hydration regimen.

Lastly, if you suspect that you’re severely dehydrated, seek medical attention immediately.

Is it better than water for hydration?

While water is viewed as the gold standard for hydration, it lacks important electrolytes that are important for restoring your fluid balance.

As such, you may want to choose an electrolyte-containing beverage like milk for rehydration, especially when you may not be getting enough electrolytes from your diet, such as during times of illness.

In fact, the above mentioned 2007 study found milk to be better than water or a sports drink for treating mild dehydration following exercise (8).

In addition, the aforementioned 2015 study on the hydrating effects of 13 beverages found that milk was superior to water at preventing dehydration (9).

Considering that not everyone prefers to drink milk, other hydrating beverage options include sports drinks, orange juice, or commercially made hydration drinks. Just make sure that your choice fits your overall nutrition and calorie goals.

Summary

Data suggests that cow’s milk is superior to plain water when it comes to maintaining fluid balance. As such, it may be a fitting beverage during times of mild dehydration.

While plain, full fat cow’s milk tends to be the most popular type of milk consumed worldwide, it’s worth considering the hydrating effects of other types of milk.

Low fat, skim, or fat-free milk

To reduce their overall fat or calorie content, some people opt for either low fat, skim, or fat-free milk.

When it comes to hydration, skim milk appears to be slightly more hydrating than full fat milk, which may have to do with its reduced fat content (10).

Therefore, for those looking to reap the hydration benefits of cow’s milk while also cutting down on calories, skim milk may be a better option.

Chocolate milk

Chocolate milk generally consists of a chocolate syrup mixed into either full fat or low fat cow’s milk.

It’s been touted as an excellent recovery beverage following exercise due to its balanced ratio of protein, carbs, and electrolytes.

Some studies confirm this acclamation, suggesting that chocolate milk is superior to water or other post-workout carb-containing beverages (11, 12, 13).

That said, further high quality research is needed to determine whether chocolate milk is better than regular milk for hydration purposes.

It’s also important to note that it generally contains a high amount of added sugar and calories, which makes it an unsuitable beverage choice for some people.

Nondairy milk

Given the rising popularity of vegetarian and vegan diets, many nondairy alternatives to cow’s milk have become available in recent years.

While some of these alternatives seek to provide a nutritional content similar to that of cow’s milk via fortification, many fall short on protein content. Here’s how popular milk alternatives compare with cow’s milk:

Furthermore, milk alternatives sometimes contain added sugars, so make sure to read the nutrition facts panel before making your purchase.

Summary

Though full fat cow’s milk is generally the most popular option, some prefer other milk alternatives. When it comes to hydration, you should review the nutrition facts to ensure a sufficient electrolyte content.

While severe dehydration is rare among healthy people, mild cases can occur, especially during times of increased sweating or illness. The most practical method of determining your hydration status is to examine your urine color.

If you find yourself becoming dehydrated, it’s important to drink enough electrolyte-containing fluids to replenish those that were lost.

Cow’s milk can be a fitting beverage option for rehydration due to its electrolyte content. Plus, it’s a good source of protein. Still, before making it your go-to rehydration drink, keep in mind that it’s relatively high in calories per serving.

Many milk alternatives contain fewer electrolytes than cow’s milk and may also contain added sugars. Thus, it’s important to read the nutrition facts panel before making your beverage choice.

If you worry you’re experiencing a more severe case of dehydration, it’s important to consult a healthcare professional for a further workup.