Does Milk Count as Fluid?

Cow’s milk is still one of the most-consumed beverages in America. But does it hydrate as well as water? Read on to see what experts say.

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milk hydration
Drinking milk is associated with a lower risk of many chronic diseases.Irina Polonina/Stocksy

At one time, milk was the OG healthy beverage. With protein, calcium, and vitamin D, it was considered an essential part of a balanced diet. Dairy milk is packed with nutrients, but its production is also a source of greenhouse gasses, according to the Harvard T. H. Chan School of Public Health. Many people have sensitivities to lactose, the sugar in cow’s milk, as well. In the United States, more than one-third of adults have difficulty digesting lactose, according to the National Institute of Diabetes and Digestive and Kidney Diseases. As demand for dairy-free alternatives grew, the market expanded beyond soy. Today you can even find “milk” made from pea protein potatoes on grocery store shelves!

Even though Americans are drinking less than ever — consumption of cow’s milk fell by 42 percent over the past fifty years, according to CBS News — it is still one of the most commonly consumed beverages in the United States. The average American family drinks about 19 gallons of milk each year, according to U.S. Department of Agriculture (USDA)?data.

And research has found that there are plenty of good reasons to enjoy a glass. A review of 41 meta-analyses published in January 2021 in Nutrition & Metabolism found that the benefits of drinking milk outweigh the risks. The review found that drinking more milk may increase the risk of acne, Parkinson’s disease, and prostate cancer, however, it may also decrease the risk of obesity, osteoporosis, heart disease, stroke, high blood pressure, colorectal cancer, and metabolic syndrome. But while drinking it may be good for your bones and other reasons, how much does this dairy beverage help meet your hydration needs?

Being well-hydrated plays a huge role in overall health. It helps in regulating body temperature, sleep, brain function, and even mood, according to the?Centers for Disease Control and Prevention (CDC). The?National Academies of Sciences, Engineering, and Medicine advises that women get about 2.7 liters (L) of fluid per day and men get about 3.7 L per day. About 20 percent of those amounts comes from the foods you eat, which means women should aim to drink about 2.2 L (nine 8-ounce cups) of water per day, and men should aim for 3.0 L (13 8-ounce cups). Of course, a number of factors affect fluid needs including activity level, life stage, and diet. For a more personalized recommendation, use a hydration calculator.

If reaching those daily fluid goals seems daunting, it may help you to know that, while water is generally the best source, other beverages, including milk, can also help. But just how much? Read on to find out.

Water vs. Milk: How Do They Compare?

Water is the “gold standard” when it comes to hydration, but milk isn’t far behind. Milk is about 90 percent water by weight, according to data from the USDA, which means you’ll be getting plenty of hydration when enjoying a glass. And unlike water, cow’s milk also contains valuable nutrients your body needs, including protein and vitamins A and D. Plus, milk is a source of electrolytes calcium, sodium, potassium, and magnesium. All of these nutrients can make dairy milk part of a healthy diet. A?review published in October 2018 in European Journal of Sport Science suggested that it may be a great post-workout beverage for muscle recovery. The type of protein in milk has also been linked to increased satiety (the feeling of fullness) and may help you eat less and lower blood sugar levels, according to past research.

Nutrition Facts of Milk

According to the USDA, 1 cup of low-fat (1 percent) dairy milk provides 106 calories, 8 grams (g) protein, 2 g fat, 13 g carbohydrates (mostly from natural sugars), 310 milligrams (mg) of calcium, 253 mg phosphorus, 391 mg potassium, 96 mg sodium, 143 micrograms (mcg) vitamin A, and 2.6 mcg vitamin D.

Dairy-free milk alternatives vary greatly in their nutritional profiles, so it’s important to read the nutrition facts and ingredients list and look for an option that meets your dietary needs. Since dairy milk provides calcium and vitamins A and D, it is best to look for an alternative that provides similar amounts of these nutrients. While all dairy and dairy-free milks will count toward your hydration goals for the day, if you do opt for a dairy alternative, be sure to read the nutrition facts label carefully as you’ll want it to be replacing as many of the nutrients in cow’s milk as possible. The alternative milk sector is rapidly expanding and new products are available all of the time. While many of the alternatives are lower in calories than milk, many also lack the valuable nutrients that dairy milk offers such as calcium and vitamin D. If you choose a dairy-free option, be sure to replace these important nutrients in your diet through other foods.

What About Milk Makes It Hydrating?

Milk’s high percentage of water makes it a natural hydrator. The electrolytes milk contains — mainly sodium, potassium, and magnesium — also contribute to fluid balance in the body according to the Cleveland Clinic. All in all, milk is an excellent source of both hydration and nutrition!

Milk vs. Soy Milk: Which Is More Hydrating?

Soy milk is a common substitute for dairy milk and it’s only natural to wonder how they compare when it comes to hydration and nutrition. In order to limit the amount of sugar you’ll get, it’s important to choose an unsweetened soy milk. Per 1-cup serving of plain, unsweetened soy milk, you can expect to get about 80 calories, 7 g protein, 4 g fat, 3 g carbohydrates, 300 mg calcium (making it an excellent source), and 3 mcg vitamin D (making it a good source). In other words, soy milk is nutritionally comparable to cow’s milk. According to data from the USDA, it’s also 92 percent water by weight, making it an excellent hydrator. Like milk, soy milk contains calories and protein (in contrast to a beverage like water), so it will be satiating (helping you to feel full) while also offering a healthy dose of calcium and vitamin D.

Types of Milk: How Hydrating Are They?

The biggest factor in how hydrating a glass of milk will be is the percentage of water that it contains. While the protein, carbohydrate, vitamins and mineral levels are almost exactly the same across all types of dairy milk, as the fat percent decreases, the amount of water that the milk contains increases. As a result, you’ll find that skim milk is the most hydrating and whole milk is least hydrating. Here are the percentages of water that you can expect from each type of milk according to the USDA:

When it comes to diary-free “milk,” there is no shortage of options available. You will find most alternative milk options fall around the same range as dairy milk in terms of percent water content. Oat milk, for instance, contains 90.6 percent water by weight according to the USDA.

Health Benefits of Milk Beyond Hydration

Beyond hydration, milk offers myriad health benefits. For example, 1 cup of milk is a good source of protein, vitamin A, and vitamin D and an excellent source of calcium, and phosphorus. As the National Institutes of Health (NIH)?point out, calcium is essential in the building of strong bones and teeth and milk is one of the most concentrated sources of this important nutrient.

Tips for Enjoying Milk to Maximize the Perks

Whether you enjoy dairy or dairy-free milk, the No 1. key to maximizing the nutritional benefits is to choose wisely. Read the nutrition facts label and ingredients list to choose the best fit for your nutritional goals. While all milks (dairy and dairy-free) will offer approximately the same hydration benefits, they can vary greatly in the macronutrients, vitamins, and minerals that they offer. For best results, choose a milk variety that does not have any added sugar as the American Heart Association recommends limiting added sugars as much as possible.

Should You Drink Milk to Stay Hydrated?

Dairy milk can absolutely be a nutritious part of any hydration and healthy diet plan. It’s important to note, however, that given its calorie content and high satiety, it should not be used to replace water by any means. You couldn’t drink enough milk in a day to stay appropriately hydrated, but it can be a nutritious way to work toward your overall hydration goal. If you choose not to drink dairy milk because of an intolerance, allergy, or for environmental reasons, be sure to choose a nondairy alternative that offers the vital nutrients your body needs especially calcium and vitamin D — both of which are crucial for bone health at every age according to the NIH.