How much protein in milk?

We all know about the basic food groups: dairy, fruits, vegetables, grains and cereals, and meats, and we all know each of these food groups has a different amount of nutrients in them.

Each one of these food groups is normally associated with a different set of nutrients as well, with grains being more associated with carbohydrates and dairy being more associated with calcium. 

How much protein in milk?

But when you are on a diet or require strict dietary needs in your diet, then problems and confusion begin to arise.

For example, if you needed to stop eating grains because you had developed celiac disease, then how would you go about getting your supply of carbohydrates? While difficult, a lot of other foods contain more nutrients than the one dominant one we give it credit for, and so it is possible to make up your nutrients by eating a plethora of different foods. 

One of the most interesting is dairy, and some products in dairy have vast reservoirs of nutrients, while others have none at all.

One of the most intriguing is milk, and one of the things people ask a lot about it is: how much protein is in milk? Well, in this article, we will take a closer look at the nutrients of milk and see just how much protein it contains. 

Protein in milk

The first thing we want to do is define what is meant by proteins. When we refer to proteins, we mean amino acids (or the building blocks of proteins), which means they are made from nitrogen and carbon atoms.

There are 20 amino acids that can be used to create proteins, but not all of them are found in equal amounts within our body.

The ones that are present in the greatest abundance are called essential amino acids (EAA). These are arginine, histidine, lysine, methionine, phenylalanine, threonine, tryptophan, valine and leucine.

They cannot be synthesized by the human body and must be consumed through our diets. So, how many EAA does milk have?

Well, there are two types of proteins in milk: casein and whey. Casein makes up about 80% of the total proteins and whey makes up the remaining 20%.

Within casein, there are three main components: alpha-casein, beta-casein and kappa-casein.

Alpha-casein makes up 40% of the total caseins and is composed of four subunits. Beta-casein makes up 60% of the total casein and is also composed of four subunits, and kappa-caseins form 10% of the total caseins.

Whey consists of only one type of protein, and it is called beta-lactoglobulin. This accounts for approximately 70% of the total whey in milk. In fact, there are more beta-lactoglobulins in milk than any other protein. 

Now, let’s talk about the percentage of protein in milk. If we were to multiply the number of grams of protein per 100 ml of milk by the volume of milk, we could find out how much protein is in a cup of milk. But before we get into that, let us talk about the nutritional value of milk.

So, how much protein is in milk?

According to the USDA National Nutrient Database, 1 cup of whole milk contains 8 g of protein. Of course, this figure represents the average across the United States, but it still gives an idea of its nutritional value.

However, if we divide the 8g of protein into 100ml of milk, we end up with 0.8g/100ml.

Now, if we want to compare this to another product, like beef, then the protein content of beef is 18g/100ml.

Even though that is almost double the protein content of milk, it is important to keep in mind that milk is a complete protein source. That means that it provides all eight essential amino acids necessary for humans. 

Since milk is a complete protein, it does not require additional sources of protein such as meat or eggs to provide adequate levels of these essential amino acids. So, although milk has less protein than beef, it provides enough protein for your daily needs.

Nutrients in milk

Now that we know how much protein is in each cup of milk, let us look at some of the nutrients in milk. Milk is high in calcium, phosphorus and magnesium. It also contains sodium, potassium, zinc and vitamin B12.

As you might expect, fat is also abundant in milk. A cup of milk contains 3.5 grams of saturated fats, while a cup of skim milk contains just 2 grams.

Another way to look at this is that if we take the 7 grams of protein in milk and divide it by the 4 grams of carbohydrates, we end up with 1.25.

This means that every gram of carbohydrate in milk contributes to half a gram of protein.

So, when choosing between skim milk versus whole milk, choose whole milk because it will contribute more to your overall nutrition intake.

Is skimmed or low-fat milk healthier than regular milk?

When it comes to milk, there are pros and cons for each kind. Whole milk is considered to be better because it provides more nutrients and vitamins than skimmed or low-fat milk.

However, skimmed or low-fat milk is still a good source of calcium and vitamin D. It also helps prevent osteoporosis.

Skimmed or low-fat milks are usually fortified with some additional vitamins and minerals such as vitamin A, riboflavin, niacin, folate and potassium.

On top of that, they contain less lactose than whole milk. Since skimmed or low-fat milk have less lactose, it doesn’t cause digestive problems like plain milk does.

The downside of skimmed or low fat milks is that their protein content is lower than that of whole milk.

So, if you want to increase your daily intake of protein without consuming too many calories, consider drinking skimmed or low-fat milk instead of regular milk.

Also, keep in mind that the protein content of skimmed or low -fat milks varies widely among different brands.

So, make sure you check the label to see what exactly you are getting.


Even though the protein content of milk is overall lower than other foods, due to the huge amount of different proteins in milk, it is a perfect way to add protein to your diet.

It is also a lot easier to drink a glass of milk than it is to put other prominent protein sources in your diet without changing existing meals.

Kevin Harris