What Does Protein Powder Do?

Written by Ben Carlisle

Last updated on: Sep 17, 2022

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Protein powders can be taken by anyone who is looking to boost their levels of protein and amino acid levels. They are frequently taken by athletes as they are a quick and effective way to help maximise their fitness goals- whether it is to lose weight or gain muscle mass.

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In addition to this, vegan protein powders help to support a vegan lifestyle as sometimes those living off plant-based foods can struggle to get all of the essential vitamins and amino acids our bodies need (1).

Protein powders also come with the added benefit of contain lots of added minerals and vitamins which our bodies need and people with certain health conditions may benefit from taking one particular form of protein over another. For example, the milk protein found in both whey and casein powders can contain up to 50% of the daily recommend allowance of calcium and there is evidence to suggest it can support vascular health (2).

There are many different types of protein powders available on the market; whey, egg white, diet whey, pea protein, hemp, soy- the list goes on. In addition to this, these protein source are produced by a range of brands and manufacturers. This means it can be a bit of a minefield working out which protein sources is the best for you. Before selecting which protein to take it is beneficial to have a clear goal of what you want your protein powder to help do.

Muscle Growth

If your aim is to improve your muscle growth then protein powder is able to help stimulate and enhance this growth. During a workout or resistance training the muscles in our fibres experience structural damage. Our bodies uses protein to build and repair this muscular damage and to fuse broken muscle fibres back together. It is through this process our muscles are able to increase in size and strength.

Studies have also shown the consumption of protein as a supplement alongside a healthy diet is a great way to maximise your lean body mass index, whilst also improving upper and lower body strength (3).

Protein powders contain different levels of protein so this is something you will want to look into before selecting the variety of protein you want to take. Science shows complete protein sources which also contain high levels of BCAA leucine are the best choice for those working on their fitness (4).

The BCAA’s also known as branched chain amino acids are key components of muscle protein synthesis as they include the amino acids; leucine, isoleucine and valine (5).  There is evidence to suggest BCAA supplements can enhance lipid oxidation during exercise (6). In addition to this, studies have shown BCAA’s are able to support muscle recovery (7).

Weight Management

Protein powder is very versatile. Its ability to make you feel full for a sustained period of time helps those who are trying to lose weight and for this reason it is often taken as a substitute meal (8). In addition to this, manufacturers have also made diet protein powders, which have added ingredients in to improve weight loss results.

For those aiming to lose weight following a calorie deficit diet, Diet protein powders are a good choice. Typically, diet protein come with the main protein source as whey with a vegan blend alternatives also readily available.

Why is protein powder helpful with weight loss? Research has shown high protein diets are able to increase energy expenditure, whilst also helping to control appetite and improve feelings of satiety (9).

What’s different about diet protein powders compared to normal ones? They include added ingredients; which research has suggested could aid the body with burring fat and boost its metabolic rate. These ingredients include CLA (Conjugated linoleic acid), acetyl l-carnitine and Green Tea. Once again, these ingredients are seen in both animal- based and vegan diet proteins. But what do these ingredients do?

L-Carnitine is a low-molecular-weight compound obtained from the same diet as the essential amino acids’ lysine and methionine (10). Studies have shown L-Carnitine improves metabolism and helps to transports fatty acids into your cell’s mitochondria (11).

Green tea extract is included in a concentrated form in some diet protein powders, which means it contains high levels of catechins and moderate levels of caffeine. Research has shown consuming green tea can increase your body’s expenditure of energy over a 24-hour period, making it a suitable component to aid with weight loss (12).

Currently, only animal studies into the ability of CLA to reduced body fat mass have been undertaken. However, these studies imply, it is an effective substance to assist with fat loss (13).

Varieties of Protein Powder

Whey Protein Powder

Whey protein powder is a highly popular protein powder, which provides high quantities of protein per serving and all nine of the essential amino acids (1). Whey protein powder is made out of the milky by product of cheese, called whey this process does mean it is unsuitable for vegans (14).

Whey protein comes in different forms, whey protein isolate, whey protein powder and diet whey protein. Whey protein isolates have been identified in studies as the purest protein source available, with it containing protein concentrations of 90% or higher (15).

Whey protein is a complete protein source which contains high levels of the essential and branched chain amino acids. It also contains high levels of the BCAA’s, which are known to play an important role in the maintenance of tissue and prevention of catabolic actions during exercise (4). Making it a good protein choice for those looking to increase their muscle and weight gain.

Studies have also demonstrated whey protein powder has properties which have a positive effect on the body’s feelings of satiety and fullness (16). This makes whey protein a great choice for those seeking to lose weight. Furthermore, there is evidence to show by supplementing a meal with whey protein powder you are to lose weight, whilst also maintaining your lean body mass (17).


Casein makes up between 70-80% of the protein in milk. Casein protein is extracted from skim milk. The first step if for the fats, carbohydrates and whey to be removed. Next, the remaining milk curds are cleaned and drained. They are then left to dry before being ground into powder.

Casein is often referred to as a slowly digested protein as the amino acids found within casein stay in our bodies for between 4 and 5 hours after being broken down (7).  Due to this, casein is often referred to as a slowly digested protein. A study undertaken to compare the reactions of young men to taking whey and casein proteins found slow digested dietary protein (casein) induced a greater protein gain than a fast one (whey protein) (18). This could suggest casein protein consumption could particular improve muscle preservation in young men.


Soy protein powder is made from defatted soybean flakes. These flakes are washed in water or alcohol, this process removes the sugar and dietary fibre stored within them. Next, they are dehydrated then made into a powder. As it is void from lactose, a common allergen, soy protein powder is used to make the infant soy milk alternative for babies with allergies. It is also used lots within dairy alternative foods. Soy protein is a complete protein and its high protein content mean it can help with weight loss by making your body feel full.


Pea protein powder is made from yellow split peas. The shell of the pea is removed and the pea protein extracted. It is then left to dry out before being ground into a fine powder. Manufacturers then add it to water as this removes the fibre and starch. Similarly, to soy, pea protein is free from lactose making it a great option for those who are sensitive to dairy products.

For those looking to build muscle using a vegan friendly protein source, Pea protein is a great option. Whilst there is some debate into whether pea protein is a complete protein source, due to the fact it is low in methionine, the general consensus feel it is. In addition to this, Pea protein contains a good source of the BCAA, with some brands being able to match the levels shown in whey protein powders (19, 20).

One study suggests pea protein hydrolysate was more effective at increasing feelings of fullness and the curbing the desire to snack, than its animal-based rival’s milk protein and whey protein (21). However, more research into the accuracy of this finding does need to be undertaken.

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Additional Health Benefits of Various Protein Powders

Not only is pea protein effective at making the body sated it is hypo-allergenic, as it is free from lactose and the 7 other main allergens. A study undertaken on lab rats, suggested the high levels of amino acids, including arginine, found it pea protein aids the body with blood flow, as well as improving the health of our hearts (22).

In addition, pea protein has good levels of the essential amino acids; leucine, isoleucine and valine which play critical roles in the regulation of energy homeostasis, nutrition metabolism, gut health, immunity and disease (23). Finally, it contains a good source of iron making it a quick and effective way to top up iron levels each day.

Research into the nutrients contained in soybeans demonstrated all forms of soybean accrue polyphenols (24). Polyphenols is a type of antioxidant which could help our body with cell damage or conditions such as heart disease (25). Interestingly, there is also research which implies populations with diets rich in soy protein and low in animal protein also have lower risk of developing prostate and breast cancer (26).

Interestingly, there is evidence to show soy is not the only protein source which can have anti-cancer effects. A study into whey protein sub fractions reflected whey protein also falls into this category (27). Similarly to pea protein, scientists also believe whey proteins may have a positive effect on reducing blood pressure and improving cardiovascular health in humans (28). Particularly, in overweight individuals.

Casein protein is a great source of calcium. Depending on your chosen brand, some servings hold up to 50% of an adult’s recommended daily allowance. There is also evidence which suggests, similarly to whey protein, the milk protein within casein is able to support cardiovascular health (29).

How To Safely Use Protein Powders

Protein powder is safe to consume when following manufacturing guidelines. It is important to read your chosen protein powder’s instruction guidelines carefully. The recommended levels of daily protein intake for a healthy adult is currently 0.8 grams of protein for every kilogram of body weight which translates to about 7 grams of protein every day for every 20 pounds of body weight (30).

Traditionally protein powder are added to shakes or smoothies and consumed pre or post workout, however it really is very versatile protein source. It can be added into your diet though using it within meals, for example when making pancakes, waffles or porridge.


Whilst we typically think of protein powders being taken by bodybuilders and athletes, they are in fact a great protein source for anyone to use to bolster their protein levels. There are a wide variety of protein sources used to make powders, including vegan options. Each protein source also come with their own added health benefits.

Protein powder is multifunctional, depending on what workout your pair with it and the diet you are consuming it is able to help increase muscle mass or help with weight loss journeys. This means it is important to think about which protein source will help you to best achieve your goals.

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Related Articles


1. https://pubmed.ncbi.nlm.nih.gov/30167963/

2. https://pubmed.ncbi.nlm.nih.gov/24135454/

3. https://pubmed.ncbi.nlm.nih.gov/26403469/

4. https://pubmed.ncbi.nlm.nih.gov/28642676/  

5. https://www.hsph.harvard.edu/nutritionsource/workout-supplements/

6. https://pubmed.ncbi.nlm.nih.gov/21297567/

7. https://pubmed.ncbi.nlm.nih.gov/18974721/

8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4744604/ 

9. https://pubmed.ncbi.nlm.nih.gov/28415067/

10. https://pubmed.ncbi.nlm.nih.gov/12751049/

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19. https://pubmed.ncbi.nlm.nih.gov/25628520/

20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6358922/

21. https://pubmed.ncbi.nlm.nih.gov/18345020/

22. https://pubmed.ncbi.nlm.nih.gov/27037677/

23. https://pubmed.ncbi.nlm.nih.gov/29570613/

24. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249631/

25. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3651847/

26. https://pubmed.ncbi.nlm.nih.gov/19145965/

27. https://pubmed.ncbi.nlm.nih.gov/31005617/

28. https://pubmed.ncbi.nlm.nih.gov/19893505/

29. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/

30. https://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/protein/

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