Protein Powder Buying Guide: Key Factors to Consider for Optimal Nutrition
Protein powders are not only used by bodybuilders or elite athletes, they have become a cupboard essential for many different lifestyles. With so many types of protein powders on the market, it can be hard to know what is best for you. This article will cover everything that you need to consider before committing to a powder.
Firstly, do you need protein powder?
We know the importance of protein in our diet, especially for active individuals, but protein powders are not necessarily needed.
The amount of protein we need is dependent on multiple factors from age, weight and health status. The recommended nutrient intake (RNI) for protein is 0.75g per kg of body weight (1). In most cases, achieving the required amount of protein can be done through a balanced diet.
Exercise increases the rate of muscle protein breakdown, which is why for those who are active, the requirement of protein increases to between 1.2 to 2g/kg body weight depending on the type of activity (2). For example, strength athletes will likely need more protein than endurance athletes. Goals such as weight loss or building muscle will also require more protein than the RNI.
Protein powders may be useful for those who…
have high protein requirements, due to being active or certain illnesses
are vegan or vegetarian
have a restrictive diet
lead a busy lifestyle or travel a lot
Are all protein powders equal?
Protein powders vary by brand, but the source and type of protein they contain are important to consider, as not all protein sources are equal.
Protein is made up of amino acids, which are like the building blocks of protein. Different proteins contain different combinations of amino acids. There are 20 amino acids that are needed for bodily functions, but 9 of these are considered essential. Essential amino acids are the amino acids that we cannot make within our body and so they must be obtained from food.
In general, animal sources of protein are considered ‘complete’ as they contain all nine essential amino acids. Whereas plant-based sources of protein are typically missing an essential amino acid or have lower levels of amino acids.
There are some exceptions though. Soy-based protein sources contain all nine essential amino acids, and if you combine different sources of plant proteins, you can still obtain all of the essential amino acids in your diet. These are called complementary proteins.
For this reason, plant-based protein powders are often blends of different protein types e.g. hemp and rice protein, to improve the amino acid profile of the protein powder.
Why is this important?
Some studies suggest that the ingestion of plant-based proteins leads to a lower rate of muscle repair and growth in comparison to the same amount of protein from animal sources (3).
20-40g of protein is required to maximally stimulate muscle growth and repair, but 3-4g of leucine, an essential amino acid, is also required to stimulate this process. Because plant protein sources are often lacking or low in leucine, this can influence the rate of muscle protein repair and growth.
This reduced ability of plant-based proteins to promote muscle growth is also thought to be caused by the lower bioavailability of plant protein sources. Bioavailability refers to the amount of a nutrient that we can actually absorb when it is digested. Quite often, plant-based proteins are slightly harder to digest, because they contain fibre, but also because they may contain phytates, which can decrease the absorbability of amino acids, calcium and iron (4).
For this reason, a plant-based protein powder may be beneficial, as powders are more concentrated sources of protein, meaning that they can be more easily digested and absorbed than getting protein from plant sources.
This of course does not mean that all your protein should come from protein supplements if you’re a vegetarian, as whole food sources of protein provide us with lots of other nutrients than just protein, but it could mean that a powder can be beneficial and convenient following a workout.
Types of animal protein powders
Whey: This is the most common type of protein powder. It is fast to digest and rich in essential amino acids making it great for post-workout or adding to meals or shakes throughout the day.
Casein: This is also made from milk but it is slower to digest.
Collagen: Collagen is derived from bones and muscle tissue of animals or fish, and has recently become more popular for the benefits that are associated with it and skin, hair and gut health.
Egg white protein: for those who have milk protein allergies, egg white protein powder can be a popular choice. It is also more of a concentrated source of protein, as it doesn’t contain fat or carbohydrates as milk does.
Types of plant-based protein powders
Soy: Soy protein powders provide a high amount of protein and all essential amino acids
Pea: This is often derived from yellow split peas. Interestingly, muscle gains were similar in a study that compared pea and whey proteins (5). This is likely attributable to the fact that pea protein is naturally rich in leucine.
Hemp: Hemp protein is often combined with another plant-based source of protein, like rice or pea protein as it is low in leucine.
Because plant-based sources of protein are typically higher in carbohydrates or fat in comparison to animal protein sources (i.e. chicken breast vs beans), they often provide lower amounts of protein per serving.
With this in mind, an isolate version of a plant protein can be preferable, like a soy or pea protein isolate. As the name suggests, an isolate protein powder means that it undergoes further processing than a standard protein powder. This results in a higher quantity of protein per serving and less carbohydrates, fibre and fat.
What to consider when buying a protein powder
Aside from deciding what type of protein powder to choose, there are other things that may influence your decision to purchase a certain supplement.
1. Check out the other ingredients
Protein powder supplements are rarely pure protein powder, which is not a bad thing as they wouldn’t be very palatable if they were purely powdered protein.
Ensure to check the ingredients list, particularly if you have allergies or sensitivities.
Sweeteners
Sweeteners are commonly added to protein powders. This could be normal table sugar or artificial and natural sweeteners.
Whilst these can be helpful to keep our free sugar intake low, some people may not tolerate some sweeteners as well as others, such as individuals with IBS. For example, sugar alcohols, like sorbitol, maltitol and erythritol can cause digestive issues as they are treated as dietary fibre in the body.
If you know you don’t tolerate these types of sweeteners, it may be worth looking for a protein powder that uses normal sugar, or a natural sweetener like stevia.
Flavourings
Most protein powders are flavoured as well as sweetened, as it might suggest on the label. These can be naturally or artificially flavoured. Artificial flavours often get a bad reputation, however, artificial flavours are generally recognised as safe when consumed in small amounts, such as in protein powders (6).
Added supplements
Some protein powders also included added supplements such as BCAAs, creatine, digestive enzymes, probiotics or omega 3 or 6 fatty acids.
Whilst this sounds beneficial, the amount added could be inadequate amounts to obtain any benefits.
2. Consider what you want out of a protein powder
Protein powders are very versatile, so it can be helpful to think about what you will most likely use protein powder for such as in your food, in baking or straight up in a protein shake.
If it is for convenience, where you are adding it to your current meals or taking it as a protein shake, you will want something that mixes well and perhaps has a neutral flavour so that you can use it in different ways.
If you have goals such as weight loss, you may want to choose a supplement that has a high protein-to-calorie ratio, whereas if you are looking for a supplement to support your sports performance or recovery, you might want something that contains some carbohydrates too.
If you’re planning to have a protein shake following a workout, one which contains some carbohydrates can be preferable to support recovery.
3. Taste preferences
There’s more to taste than just flavour. Taste is also impacted by mixability and textures. The flavour and taste of a protein powder can impact how you consume it.
Plant-based protein powders tend to be grainier or have a more ‘earthy’ taste than whey or casein. Mixing these with plant milk or adding them to meals may be preferable to drinking them as a protein shake.
Unflavoured protein powders can be a good choice if you dislike artificial sweeteners, and want to use protein in multiple ways. However, this might not be as enjoyable if you are looking to drink it on its own.
Before you commit to a flavour, it might be worth getting a sample pack or single-serving sachet of the protein powder.
Takeaway
Whilst protein powder is not essential, it can be both beneficial and useful. If you are struggling to meet your protein intake, protein powder can be used to fortify meals or to add in via a shake.
It is important to remember that protein powders are supplements, meaning they should supplement the diet, rather than replace anything.
References
Department of Health. (1971). Dietary Reference Values. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/743790/Dietary_Reference_Values_-_A_Guide__1991_.pdf
Jäger et al. (2017) “International Society of Sports Nutrition Position Stand: protein and exercise” https://pubmed.ncbi.nlm.nih.gov/28642676]
Pinckaers, P. J., Trommelen, J., Snijders, T., & van Loon, L. J. (2021). The anabolic response to plant-based protein ingestion. Sports Medicine, 51(1), 59-74.
Gilani, G. S., Xiao, C. W., & Cockell, K. A. (2012). Impact of anti-nutritional factors in food proteins on the digestibility of protein and the bioavailability of amino acids and on protein quality. British Journal of Nutrition, 108(S2), S315-S33
Babault, N., Païzis, C., Deley, G., Guérin-Deremaux, L., Saniez, M. H., Lefranc-Millot, C., & Allaert, F. A. (2015). Pea proteins oral supplementation promotes muscle thickness gains during resistance training: a double-blind, randomised, Placebo-controlled clinical trial vs. Whey protein. Journal of the International Society of Sports Nutrition, 12(1), 3.
Centre for Food Safety, Nutrition A. Generally Recognised as Safe (GRAS). (2019). U.S. Food and Drug Administration. https://www.fda.gov/food/food-ingredients-packaging/generally-recognized-safe-gras
