Casein is a healthy and effective support for losing weight


Taking a casein protein supplement will increase your daily protein intake. This is an important factor in weight loss because increase of protein in your diet in general will increase your calorie burn rate. Casein also supports weight loss specifically because it is digested slowly and reduces appetite making it easier to eat less. Casein is a natural milk-based protein.


This article will explain why it is a good idea to take a casein protein supplement if you want to lose weight. It will also explain in detail what it is about casein that can support weight loss, as well as describing other health benefits of casein.

What is casein?

Casein is a natural milk-based protein supplement. Casein is exactly the same kind of protein you find in cheese, yogurt and milk. Casein protein supplement is natural milk protein in concentrated powder form.

Casein is high quality protein

Many food items are rich in protein. Seen from the perspective of a human being though, not all proteins are equally valuable. There are some proteins that the human body needs more than other proteins. Casein contains an ideal composition of proteins for humans.

Casein is a complete source of protein. It provides you with all the amino acids that are essential for your body’s maintenance, repair and growth.

How much protein is there in casein?

A pure unflavored casein powder contains approximately 80 grams of protein per 100 grams of powder. In other words, it contains around 80% protein. You will find products though, that have a protein content down at around 65% or lower. Make sure you take a good look at the list of ingredients and the nutrition facts of a product, before you decide on your purchase.

Many protein supplement products come with a scoop that gives a 30 grams servings size. So, one brimful scoop contains 30 grams of casein powder. If the powder is at 80% protein, then one serving will contain approximately 24 grams of protein. For comparison, one large egg contains 6 grams of protein. This means, that taking one 30 grams scoop of casein gives you the same amount of protein as if you eat 4 large eggs.

How does casein help me lose weight?

1 – Increase your calorie burn rate

Firstly, increasing protein in your diet in general supports weight loss by boosting metabolism and the body’s overall calorie burn rate. The body simply burns more calories in a day, if a larger proportion of the food is protein. In that way, a protein rich diet leads to weight loss even if you do not pay any special attention to reducing calories, portions, fat or carbohydrate.

2 – Make you feel full for a long time

Secondly, casein in particular supports weight loss by giving a feeling of being full, of satiety, and reducing the appetite [01]. This is effect is partly caused by the simple fact that it takes a long time for casein to be digested, and partly mediated by the nervous system.

3 – Retain your muscle mass

Thirdly, casein is digested slowly and thereby releases a stream of amino acids in your bloodstream for up to 7 hours. An effect of this continuous supply of amino acids to the bloodstream, is that the level of amino acids in the blood stream does not go too low. When the amino acids level goes too low, the body will start taking amino acids from the muscles to keep up a minimum level in the blood stream. When this happens, the body loses some muscle mass. The casein that is being slowly digested blocks this from happening.

Losing muscle mass in fact has a long range of negative health effects. The one we focus on here and now, is that when muscle mass decreases, the body will have a lower base line calorie burn rate. The more muscle we have, the more calories we burn even when resting, and the easier it is to lose weight. So, to put it short: casein helps you retain the muscle you have also when there is far in between meals, thereby keeping your calorie burn rate higher.

It may sound a bit dramatic that the body will start feeding on its own muscle mass, but it is completely normal. It is an every day event if there is far in between meals. It is like the body in a certain sense treats the muscle mass as an amino acid bank. It adds muscle when it has enough amino acids available to make a deposit, and it draws out amino acids from the bank when the bloodstream level runs too low. It is a continuous process and balance between building and destroying.

The main point here is, that the body will not borrow amino acids from its own muscles for as long as it is still feeding on casein. Casein supports retaining lean muscle mass [02].

4 – Grow new muscle

Fourthly, casein will support growth of new muscle [03]. Here we are not necessarily talking about building muscle in the way bodybuilders work on it. We are talking about the mild to moderate increase of your lean muscle mass that will occur naturally over some time if your diet is richer in protein.

If you gain a bit more muscle, you will then also gain a slightly higher calorie burn rate. Again, a higher calorie burn rate will make it easier for you to lose weight and keep your weight low. If your body has more muscle, you will burn more calories without having to work for it. Casein will help you grow a bit more muscle, whether you train or not.

How do I take casein to lose weight?

Here are some suggestions for how you can add casein to your diet to support weight loss:

1 – With breakfast

Take a casein shake with your breakfast to make sure it is rich in protein. Also to make sure that you will feel full all the way till lunch and feel less craving to eat snacks. If your breakfast is a bowl of cereals, it is perfect to mix a serving of casein into it.

2 – Before lunch and dinner

Take a casein shake before lunch or dinner to make you feel less hungry when you eat your meal. When you are less hungry you will tend to eat less. When you look at the casein shake plus the meal as a whole, it will most likely be higher in protein and lower in carbohydrate, than if you don’t take a casein shake.

3 – Before bedtime

Take a casein shake before bedtime on any day and especially on days where you have been working out. This will support your muscle recovery, as well as support retaining existing muscle plus growth of new muscle overnight [04], [05].

4 – Smoothie with casein

If you add a serving of casein to a smoothie, and perhaps a few cashew nuts or almonds, your smoothie will actually be a full meal containing both protein, fat and carbohydrate, and on top of that some fiber, vitamins and a good portion of calcium.

It is important to mention that if the casein powder you have, is fresh and of a good quality, it can be very delicious! You may be surprised how great-tasting a mango smoothie gets when you add a shot of vanilla casein to it.

Convenience matters

Casein powder provides a very easy and convenient way to add more protein to your diet. In a few minutes, you can get the same amount of protein that you would otherwise have to eat a full meal to get.

It takes only a couple of minutes to add 300ml of water to a shaker, add a 30 grams scoop of casein powder on top, shake for 10 seconds, and drink the shake. There is very little time spent on shopping, cooking, eating and dish washing.

Casein, exercising and muscle growth

Muscle synthesis continues for up to 48 hours after exercise. This is a really important fact to know about exercise and muscle growth.

Think about this. When the muscle synthesis continues for up to 48 hours after training, what do you think happens to the amino acid level in the bloodstream in your early morning sleep, when all the muscles you exercised 8 hours earlier have been saying: “Give me! Give me! Give me amino acids!”? What happens is that the amino acid level in the blood stream drops low.

Then, the body will have no other choice than to start re-supplying amino acids from the muscle mass in order to keep up a necessary minimum level. Amino acids are continuously necessary for the basic functioning of the cells in your brain, nerve system and organs. The body will prioritize these purposes higher than muscle growth.

If you do not take casein at bedtime on the days you have exercised, then in terms of muscle mass, you will lose some of the effect of your training during your sleep.

Why does it take a long time for casein to be digested?

The reasons why casein digests slowly are to be found in its molecular and chemical characteristics. On the molecular side we have the situation that the proteins that make up casein, are organized in very large kind of apple shaped or ball shaped supra molecules. These supra molecules are actually so big that you can feel them with your tongue when you drink a casein shake. There is a kind of slightly gritty or sandy feel to it when you drink a casein shake.

Because these supra molecules are as big as they are, and are as tightly structured as they are, it simply takes a long time for digestion to pick them apart.

There is also a related chemical side to the long digestion time. When casein powder is mixed with water, it will have a neutral value around pH 7.0. At this neutral pH value, the casein will be nicely blended with the water. Not completely dissolved, but nicely blended. The shake will be almost as thin as water and easy to drink.

When the casein enters the stomach, then gastric acid will be released in the stomach lumen and the pH value will drop to a level between pH 1.5 – 3.5. Casein thickens up already at a value around pH 4.6. At that level of acidity, the casein coagulates into the so-called curds, which are a kind of yogurt like semi-thick substance. The thick consistency of the curds contributes to making it take longer time for the digestion to process the casein.

The main reasons whey casein takes a long time to digest, are firstly that casein thickens into the curd consistency when being exposed to gastric acid. Secondly, when the digestion gradually works on extracting the amino acids, it also takes time to pick apart the tightly packed supramolecules that the proteins are organized in. In total, it takes 5-7 hours to fully digest casein.

What does high-quality protein mean?

It is mentioned in the beginning of the article that casein is called a “high quality protein”. Let us for a moment dive a little deeper into what this means.

Essential Amino Acids – “EAA” in casein

There is a group of 9 amino acids that are called Essential Amino Acids or in short EAA. They are a part of the naturally occurring amino acids in the milk protein.

The important issue about the 9 EAA’s is that the human body is unable to synthesize this group of amino acids to the same amounts that the human body needs. Synthesize means “to make them”, or to “build them up” out of other parts of the nutrition. Some of the amino acids the human body cannot synthesize at all, and others it cannot synthesize enough of. Therefore, they must be supplied in the diet.

The names of the EAA’s are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.

Casein protein contains all the 9 EAA’s. One 30 grams serving of an unflavored casein powder at 80% protein content, provides you with a total of approximately 10.4 grams of EAA. If you have a flavored casein powder, it will contain slightly less.

Branched-Chain Amino Acids – “BCAA” in casein

There is also a group of 3 amino acids that are called Branched-Chain Amino Acids or BCAA. These 3 amino acids are actually a subset of the 9 EAA’s. Again, the BCAA’s are a part of the naturally occurring amino acids in the milk protein.

The BCAA’s are leucine, isoleucine, and valine in the approximate proportions 2:1:1. People who do fitness training and want to achieve muscle gains, are often particularly interested in the BCAA’s. The BCAA’s are thought to be particularly important after training sessions for optimal muscle recovery and growth.

One 30 gram serving of a casein with 80% protein content provides you with a approximately 5.5 grams of BCAA, while a flavored casein powder contains a few percent less. For comparison, casein contains approximately 60% more EAA than soy protein.

Seen from the perspective of what a human body needs, some proteins are more valuable than others. In fact, some proteins are essential and necessary to supply through the diet. Casein is called a high-quality protein, because it supplies all the essential and necessary amino acids.

What other health benefits does casein provide?

As mentioned, casein is a complete source of protein, providing your body with all the amino acids that are essential for its maintenance, repair and growth. On top of that, casein also contains some unique proteins that may have a positive effect on the body’s immune system [06], in the form of antioxidants [07], and some compounds that provide a reduction of inflammation.

Other compounds, the so-called milk derived bioactive peptides, are shown to work against hypertension [08], [09] hereby supporting stress reduction. Other of the peptides are shown to have a positive effect on mood, and can have a mild effect towards reducing depression.

Casein is very rich in calcium. An adult needs 1 gram of calcium per day, and one 30 grams scoop of casein will provide you with 0.6 grams of calcium. This means that 60% of your daily calcium need is covered by one scoop of casein protein powder.

Can I take too much casein?

Not really. It may still be a good idea to limit the intake to a maximum of 3 servings a day.

The only people who should be careful with the amount of protein they take, are people who know they have problems with their kidneys or liver [10]. If you know you have a problem with your kidneys or liver, it is strongly recommended that you to contact your doctor and get his or her advice before you take any protein supplements.

Casein and general diet

The most important principle about creating a healthy diet, is to make sure that it is broad and varied. It is important to get your macronutrients, vitamins and minerals from many different sources. It is good to let a diet consist of meat, eggs, fish, vegetables, fruit, and a reasonable amount of carbohydrate.

It may not be a good idea to altogether replace any of your meals with casein. It is better to see the casein as a supplement you add to your meals, add to your normal diet, to give it a push towards more protein.

Can vegans and vegetarians take casein?

Vegetarian diet is defined as a diet that excludes meat and sometimes other animal products. So, whether a vegetarian can eat casein and other milk products or not, really depends on his or her personal decisions about what they choose to exclude from their diet apart from meat. If a vegetarian choses to include milk and milk-based products in the diet, he or she can take casein.

The vegan diet, however, is defined as a diet that excludes any food deriving from animals. Casein can therefore not be a part of a vegan diet.

Can I take casein if I have a lactose intolerance?

That is a question that cannot be answered by a yes or a no. You most likely can but let us look at some numbers before you make a conclusion for yourself. Most people who have lactose intolerance can tolerate approximately 2 cups or 500ml of milk in a day if it is divided into smaller quantities.

2 cups or 500ml of milk contains approximately 24 grams of lactose. One 30g serving of casein contains 1.5 grams of lactose. This is equivalent to the amount of lactose you would get in 30ml of milk. This is about a third of a deciliter or 2 tablespoons of milk.

Consequently, this would indicate that most people who have lactose intolerance may not have any problems if taking one, two or even three servings of casein in one day. Even when taking 3 servings in a day, you still only get a fifth of the amount of lactose that you would probably be able to tolerate without problems.

You can ask yourself: With the lactose intolerance I know I have, or think I may have, can I tolerate taking two tablespoons of milk? If the answer is yes, it is likely that you can also tolerate taking one 30 grams serving of casein powder. If the answer is no, you should probably not take casein.

Different versions of casein

There are several versions of casein available from different sports nutrition brands nowadays:

  • Milk Protein Concentrate, also known as MPC
  • Micellar Casein
  • Calcium Caseinate

All three are often in daily speaking simply referred to as “casein”. There are more versions of casein coming up these years, as the research and product development in the dairy industry for the sports nutrition market is intense.

The three versions mentioned above are after all not that different with regards to the amount of protein they contain, the flavor and mixing quality. They are not different at all when it comes to the properties of casein itself.

“Casein” products based on micellar casein and calcium caseinate are sometimes, but not always, a bit higher in protein content than the casein products based on MPC.

The micellar casein and calcium caseinate products tend to be more expensive, and are perhaps more kind of feinschmecker specialty supplements for experienced gymgoers.

To keep things simple, this article focuses on the casein product based on Milk Protein Concentrate, or MPC. The numbers given about protein content and serving sizes in this article are based on the numbers for MPC with 80% protein content.


Taking a casein protein supplement will increase your daily protein intake. This is an important factor in weight loss because increase of protein in your diet in general will increase your calorie burn rate. Casein also supports weight loss specifically because it is digested slowly and reduces your appetite making it easier to eat less.

Furthermore, casein has a number of other health benefits, such as supplying a solid amount of calcium as well as supporting immune function, reducing hypertension and having a positive effect on mood.