By: Matt Weik

Protein supplements are an integral part of a bodybuilding regimen. It is also used to improve stamina and performance. With many types of protein supplements available on the market, it is tough to choose between them. When picking a protein supplement that perfectly fits your specific needs and requirements, you should have a basic knowledge about the various sources and what benefits you can expect. In this article, we will discuss milk protein and whey protein to allow you the ability to choose which one you would prefer to use and when to help you achieve your health and fitness goals.

What is Milk Protein?

Casein protein and whey protein are the two types of protein present in milk. Casein constitutes around 80% milk protein, while the remaining 20% is in the form of whey protein. Both proteins can help boost muscle tissue growth. As casein protein constitutes a significant part of milk protein, the term 'milk protein' is sometimes used interchangeably with casein protein.

What is Casein Protein?

When the milk is heated in the presence of enzymes, it forms curd and whey. Curd may either be used for cheese production or processed to produce what we know as casein protein. Casein protein is an extremely slow-digesting protein that takes hours to digest and allows for a slow release of amino acids into the system (perfect for helping you stay satiated as well as anabolic).

When to Use a Casein Protein?

Casein protein has many benefits that not many people fully understand. This milk protein offers you the following advantages:

Boosts Muscle Growth

Casein protein contains all the essential amino acids. It helps improve muscle growth. As compared to placebo, casein protein can double muscle growth. 

Improved Physical Performance 

Casein has an anti-catabolic effect that can result in greater strength. The next time you're thinking about having a protein shake at night, you'll want to make sure it is in the form of a casein protein.

Burn Fat and Lose Weight

You may lose your weight either through the loss of muscle or fat or through a combination of both. However, if you incorporate casein in your weight loss regimen, you will burn more fat while also helping to retain the lean muscle you have. Casein can provide you with the best of both worlds, which is why it is so versatile.

Boosts Immunity

Casein protein is effective in boosting your immunity. It has anti-viral properties and helps modulate your immune system to reduce the degenerative impact of various diseases.

What is Whey Protein?

Switching gears, whey is the liquid part of the milk that remains after the cheese manufacturing process. This liquid undergoes various filtration processes to yield various types of whey protein. Whey protein has around 20% more leucine when compared to casein protein. Leucine is a powerful amino acid that aids in protein synthesis, regulating blood sugar levels, growth hormone production, and lean muscle tissue growth.

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When to Use a Whey Protein Supplement?

You may use whey protein for:

Fast Recovery 

Because of its rapid absorption, whey protein ensures fast recovery following an intense workout to aid in repairing and rebuilding torn down muscle fibers. 

Weight Loss

Whey protein aids in weight loss due to its effect on regulating fullness and satiety, which can help prevent overconsumption of food throughout the day.

Muscle Protein Synthesis

The use of whey protein helps initiate muscle protein synthesis and aids in increasing lean muscle mass.

What Are the Types of Whey Protein? 

The following are the various types of whey protein you'll see on the market:

Whey Protein Concentrate

This type of whey protein is the least processed. It contains approximately 70-80% whey protein. It is obtained at the primary stage after whey ultrafiltration. It has a high lactose content yet is still absorbed quite quickly as compared to a casein protein.

Whey Protein Isolate

When whey protein concentrate is purified further, to increase the amount and concentration of whey protein, we get a whey protein isolate. Whey protein isolate contains approximately 90% whey protein. It has low lactose content along with lower carbohydrates and sugars, which also helps ensure a faster absorption rate.

Whey Protein Hydrolysate

Whey protein hydrolysate is an enzymatically treated protein supplement. It has no or very negligible amounts of lactose while containing at least 90% whey protein. This protein is predigested and has an extremely rapid absorption rate – faster than any other source listed in this article.

What Are the Similarities Between Milk Protein and Whey Protein? 

Since the source of protein is similar, they do share certain similarities such as:

  • Both proteins are complete as they have all the essential amino acids
  • Both come from milk and manufactured during the synthesis of cheese
  • Both whey protein and casein protein are used as muscle-building and muscle-preserving supplements
  • Both proteins have the potential to improve physical performance as well as build and repair muscle tissue

How to Choose Between Casein Protein and Whey Protein 

Both the casein protein and whey protein supplements are a powerful source of protein. So, how should you determine which one of the two is the best protein supplement? Due to the difference in the level of various amino acids, both have their own unique advantages.

Strength and Muscle

Whey protein is rich in branched-chain amino acids (BCAAs) and has a high biological utilization rate. BCAAs are responsible for enhancing muscle protein synthesis. Researchers compared the rate of muscle protein synthesis with whey protein, casein protein, and milk protein. The study concluded that whey protein was fast, the milk protein intermediate, and casein protein was slow in the initial peak time to synthesize muscle protein. 

Weight Loss and Lean Muscle Mass

Both whey protein and casein protein promote weight loss and improve lean muscle mass. While both whey protein and casein protein can help keep you full, being that casein protein is a much slower digesting protein, it can help keep you satiated longer, which makes it a great option at night as well as between meals if needed.  

Absorption Rates

The rise of the amino acid level in plasma after the ingestion of whey protein is fast and high, while it is slow with casein protein. A study indicates that although whey protein initiates the rapid synthesis of protein, a major part of this protein is used by the body. In contrast, the protein synthesized through casein accumulates in the body over a longer duration.


Both types of protein have very different usages. Whey protein is generally opted for recovery due to faster absorption rates, which makes it the perfect post-workout recovery shake. When looking for sustained muscle protein synthesis, casein is a better option because of its slow absorption rate. Casein is the perfect nighttime protein source as it breaks down over around seven hours while you sleep – allowing you to stay in an anabolic state and improve recovery. 

Cost Comparison of Whey Protein and Casein Protein

The cost of protein supplements depends on various factors like the brand, purity, and protein type. Casein protein is usually more expensive than a whey protein powder. Among the various forms of whey protein available, whey hydrolysate is the most expensive due to its overall quality and fast absorption rate.

Why Not Combine Them into a Blend? 

That's actually a great idea, and fortunately, brands are already leveraging blended proteins that utilize both fast and slow-digesting proteins. You get all the benefits when you combine various protein sources, which makes blends a viable option for your needs.

Both whey protein and casein protein are complete protein supplements. Yet, bodybuilders and fitness enthusiasts use them for different purposes. Whey offers fast recovery while casein has a sustained muscle synthesis property. Ideally, incorporating both protein types into your daily regimen will help provide you with some great results. 

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Delicious Milk Protein Isolate Snacks

Many people think of milk protein and whey protein as powders to mix into a protein shake. While that is generally the case, MPA got a little creative and launched what they are calling Iso Poofs. These high-protein snack items contain 19g of protein, are under 100 calories, and utilize milk protein isolate. 

These any time of day snack items can be used as a snack, included in things like a salad, or tossed into your favorite dishes to add some extra protein and crunch. You could even use them in the morning as a cereal.

Being low in fat, carbohydrates, and sugar, you can eat MPA Iso Poofs without stressing over the macros or caloric content. Increase your daily protein intake, recovery, and muscle growth through the help of MPA Iso Poofs!