How Much Protein Does a Serving of Milk Have?

Ever wonder how much protein is in a cup of milk? Or how protein impacts the nutritional value of milk?  If so, you’re not alone. Whether you’re a fitness enthusiast, parent, or just a curious soul, these are good questions—read on for answers.

Is Milk A Good Source Of Protein?

Milk is a good source of protein. And there are two main reasons why: the amount of protein per serving and the quality of that protein.

While the exact amount varies per individual–based on factors including age and activity level– adults generally need 46 to 56 grams of protein per day. So, the 8 grams of protein in every cup of milk can go a long way in getting the protein you need.

In addition to being a good source of protein, milk also provides high-quality proteins. These proteins include all nine amino acids our bodies can’t create, such as leucine (one of the main amino acids that help build muscle). These nine amino acids are broadly called the essential amino acids. According to sports nutritionist and registered dietitian Leslie Bonci, owner of Active Eating Advice, they’re more common among animal-sourced foods like dairy.

“That is not to say plants aren’t important,” Bonci points out. “They’re incredibly important, but we have to get our protein needs met over the course of the day.”

Bonci explains that, with the exception of soy milk, the amount of protein in plant-based milk alternatives is “really, really low.” And they don’t have the same quality as dairy milk. “What I think is very important for people to understand is the quality of some of the individual plant proteins is less, meaning they have less leucine. And so you have to eat more of them, which you can, but sometimes that becomes a little unwieldy in terms of the amount of something.”

As an example, almond milk has roughly 1.5 grams of protein per cup. This means you would need to drink over five cups of almond milk to get the same amount of protein as one cup of cow’s milk. Even then, however, the quality of the protein wouldn’t be the same. Ultimately, it’s important for everyone to find the best sources of protein for them. And unless you have a dairy allergy, milk can be one of those good sources — even if you’re lactose intolerant. “If I mix dairy with plant-based foods, great!” Bonci says. “Because now I know that I’m getting my [protein] quality met, but I’m not going to exceed my calorie needs.”

How Much Protein Is In Whole Milk?

Milk comes in many varieties, and each one is unique for many reasons, including fat content and lactose amount. But no matter the type, all dairy milk provides the same 13 essential nutrients, including protein. This means whole milk has 8 grams of high-quality protein per cup. In fact, it has two high-quality proteins, just like lactose-free milk, reduced-fat milk, and other dairy milk.

What Are The Two High-Quality Proteins Found In Milk?

Milk contains two types of protein: casein and whey. Each one is a high-quality protein, also known as a complete protein, that occurs naturally in milk. But they’re far from identical — casein and whey can affect the body differently in unique ways.

Is Casein Protein In Milk Good or Bad For You?

Casein is the dominant protein in milk, accounting for roughly 80% of milk’s total protein. It’s also the slowpoke of the proteins because it gets digested slower than whey, resulting in a more gradual, prolonged release of its amino acids into our muscles. But being slow-acting does have its advantages.

The slower digestion of casein may help us feel fuller longer, which can be useful for weight management. Additionally, our bodies undergo a significant reset process when we sleep. So, with casein’s slowpoke nature, some scientists think consuming it before bed helps improve the repair and rebuilding of muscles as we sleep, maximizing our nightly recovery and maintenance and contributing to the reasons consuming casein foods like milk and cheese before bed may help support a good night’s rest.

Whey Protein In Milk

Whey accounts for the other 20% percent of the protein in milk, and it’s the speedier one. Whey is digested faster than casein, which allows its amino acids to release into our muscles more quickly. The rapid release of protein has its own health benefits, particularly with building muscle after a workout.

Bonci focuses on leucine — a key muscle-building amino acid — as a primary indicator of a protein’s quality. And she says that whey protein has a lot of it, which can support recovery post-workout. 

“When we exercise, we break down protein,” Bonci explains. “We’re not building when we’re exercising, unless we’re strength training. Any other cardio activity is breakdown, breakdown, breakup. And so we need to be able to bring that back on the back-end, this restorative aspect.” 

Because of this, whey’s fast-acting nature proves just as useful as its leucine content, helping enhance physical growth and recovery at any time of day — whether you’re a growing kid, an active adult, or an older adult. It’s part of why chocolate milk is a popular and effective recovery drink for professional athletes and recess all-stars alike.

Milk Protein Benefits The Body

Thanks in part to the total amount of protein it provides per serving and the quality of the two proteins it contains, milk can support improved muscle building and recovery. There are functional benefits too. Since its protein can foster sustained energy and a satisfying effect, drinking milk may help you stay focused and active throughout the day and rest easier at night.

These are just some of the many reasons milk can be a core component of a healthy diet, no matter your age. So, if it’s not already a staple for you, it may be worth considering. Ask a registered dietitian about your protein needs and explore how milk and other dairy foods can help enhance your health and wellness.