All you Need to Know About Protein Powders

The importance of protein intake for our health is due to the critical role this essential macronutrient plays in our metabolism of cells and tissues, hormone production, immunity and healthy skin (1). For those of you who actively enjoy exercise and training, protein plays an important role for muscle growth, maintenance and repair (1).

So, when thinking about the amount of dietary protein we need on a daily basis, just how necessary is it to have protein powdered supplements in our diet?

Benefits of Protein Powders

• One of the potential reasons as to why the consumption of protein powders has really increased in popularity over the last few years is due to the suggested benefits for weight loss and muscle gain (2). This is because intakes of protein have been reported to result in early satiety and fullness (3).
• Protein provides 17kJ (4kcal) of energy in a process known as ‘diet-induced thermogenesis’ in which a higher energy expenditure is produced by the body to process the protein we have ingested (3). Protein also provides less calories per gram compared to fat (9kcal/g) and alcohol (7kcal/g) (4).
• Protein powders have also become a convenient way for people to increase the protein content of their meals without exceeding the fat and calorie content for weight related goals and muscle building (2).
• They are often consumed post-training to help build muscle mass and repair following strength and resistance exercise in a process known as ‘muscle protein synthesis’ (5).

How Much Protein Do We Need?

The current Recommended Daily Allowance (RDA) of protein for a general population of inactive adults (over 18 years) is 0.8g/kg of bodyweight per daywhich results in approximately 45-56g per day for women and menaged 19-50 years respectively (1). According to the British Nutrition Foundation, the average daily intake of protein in the UK is 64g for women and 88g for men (1)which demonstrates that the current UK population is getting more than enough protein required for their general health.

Do We Need to Consume Protein Powders?

Our protein requirements do change throughout the lifespan as well as depending on our physical activity levels (8)(9).

Higher intakes of dietary protein are required for pregnant/lactating women (60g/day) (10). Older people also require higher protein intakes to prevent the loss of muscle mass, strength and function otherwise known as a condition called sarcopenia (11).

When it comes to population groups who may benefit from taking protein powders, individuals who participate in intense exercise including athletes and sports team players require significantly higher intakes of protein to support building muscle mass, repair and performance (12). Therefore, the majority of exercising individuals should consume approximately 1.2-2.0g of protein per kg bodyweight per dayto optimize their exercise induced training (13).

For those of us who engage in regular moderate exercise, the BDA reports that when energy requirements are met, a balanced diet will usually provide enough protein to meet the increased requirements associated with exercise (13).

In regard to the general population needing 0.8g/kg of protein per day, it is best to obtain protein from foods as protein supplements can lack other essential nutrients for health that can be obtained from high, quality protein foods.

Overall, the evidence base to support protein powders over whole food protein sources is low and should not be seen as a replacement for whole food sources of protein. These include –

Animal sources:

• Eggs
• Salmon
• Chicken

Plant-based sources:

• Tofu
• Soya and soya products
• Nuts, beans and legumes.
• Wholegrains

Ingredients to Look Out for in Protein Powdered Supplements

Protein powders may include other ingredients including added sugars, artificial sweeteners, colourings and flavourings, thickeners, vitamins and minerals.

In general, when opting for protein powder products, choose products with a shorter ingredients list wherever possible.

Below is a list of ingredients to be aware of as to how well they are tolerated in the body.

These include:

• Dextrin/Maltodextrinis a simple carbohydrate (sugar) often derived from genetically modified corn starch. It is used as a filler to bulk out protein and enable it to mix well. However, it can cause spikes in blood sugar due to their high glycaemic index (GI) which would be important to consider in people with diabetes as well as for our general health (14). However, this ingredient is particularly found in ‘recovery’ branded drinks as it aids a rapid replenishment of muscle glycogen stores post exercise (15). Therefore, it isn’t a ‘bad’ ingredient as such, it just depends on what your workout or training involves.
• Artificial sweetenersincluding sucralose, aspartame, saccharin. Although they contain very little calories, high intakes can lead to gastrointestinal disturbances in some people including abdominal gas and diarrhoea.
• Thickening agents and gumincluding xanthan gum manufactured from soy, corn and wheat may cause bloating and gas in some people
• Glutenis important to be aware of if you are a coeliac or gluten intolerant.
• Skim milk powders and milk solidscan cause an upset stomach in some people. They are used as an inexpensive bulking agent, but they can lack nutritional value and also trigger gut issues for those who are lactose intolerant. This ingredient is not suitable for vegans or vegetarians

Animal vs Plant-Based Proteins

Opting for animal-based protein powders commonly whey and casein obtained from milk proteins can be an efficient way of consuming protein as they contain all essential amino acids which are not made in the body and must be consumed through the diet.

Whey protein which is rapidly digested has been found to stimulate the build-up of muscle mass (muscle protein synthesis) to a greater extent than casein and also soy (16). However, whey is not suitable for vegans or those with an intolerance to dairy.

There are a variety of plant protein powders and blends available including soy, pea, rice and hemp.

Soy is a complete protein containing all EAA’s and rice protein is a medium to slow absorbing protein containing leucine which is an EAA that stimulates muscle protein synthesis (17). Pea protein has been suggested as a good, high quality vegetarian source of protein for anyone looking for an alternative to whey or soy protein (18). Hemp protein is also a great plant protein option as it is a complete protein containing all nine essential AA’s however these are in lower quantities compared to whey protein (19).

Overall, plant-based proteins are not inferior as long as you choose one or a combination of plant protein sources to ensure you get a complete essential amino acid profile or else consume higher amounts to reach your protein targets(20). There are also mixed sources of plant-based protein powders on the market that would help to avoid deficiency in certain essential amino acids.

Summary

Overall, protein powders can be used as a convenient, cost-effective and efficient way of meeting your protein targets. However, they should be combined with whole food sources in the diet and not used as an alternative. If you are struggling to meet your protein requirements, it is always best to try to increase your protein intake through high quality protein sources first to ensure you get the vitamins and minerals required to maintain a healthy, balanced diet.

References

1. Protein – British Nutrition Foundation [Internet]. [cited 2021 May 23]. Available from: https://www.nutrition.org.uk/nutritionscience/nutrients-food-and-ingredients/protein.html
2. Bodybuilding and sports supplements: the facts [Internet]. nhs.uk. 2018 [cited 2021 Jun 6]. Available from: https://www.nhs.uk/live-well/healthy-body/body-building-sports-supplements-facts/
3. Westerterp-Plantenga MS, Nieuwenhuizen A, Tomé D, Soenen S, Westerterp KR. Dietary protein, weight loss, and weight maintenance. Annu Rev Nutr. 2009;29:21–41.
4. Energy intake and expenditure – British Nutrition Foundation [Internet]. [cited 2021 Jun 13]. Available from: https://www.nutrition.org.uk/index.php?option=com_content&view=article&id=263:energy-intake-and-expenditure&catid=65&Itemid=199&showall=1&limitstart=
5. Cintineo HP, Arent MA, Antonio J, Arent SM. Effects of Protein Supplementation on Performance and Recovery in Resistance and Endurance Training. Front Nutr [Internet]. 2018 Sep 11 [cited 2021 Jun 2];5. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6142015/
6. Deighton K, Stensel DJ. Creating an acute energy deficit without stimulating compensatory increases in appetite: is there an optimal exercise protocol? Proceedings of the Nutrition Society. 2014 May;73(2):352–8.
7. Appetite-regulatory hormone responses on the day following a prolonged bout of moderate-intensity exercise | Elsevier Enhanced Reader [Internet]. [cited 2021 Jun 9]. Available from: https://reader.elsevier.com/reader/sd/pii/S0031938415000025?token=4146C0FAC7EE66A36FCFE86214279241B249A52B1ADE1487A46B60284EE4E4022693A21B8097D38BB5B3A7AB159ABDBD&originRegion=eu-west-1&originCreation=20210609153319
8. Energy and protein requirements [Internet]. [cited 2021 Jun 13]. Available from: http://www.fao.org/3/aa040e/AA040E03.htm
9. Jäger R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017 Dec;14(1):20.
10. Kominiarek MA, Rajan P. Nutrition Recommendations in Pregnancy and Lactation. Med Clin North Am. 2016 Nov;100(6):1199–215.
11. Baum JI, Kim I-Y, Wolfe RR. Protein Consumption and the Elderly: What Is the Optimal Level of Intake? Nutrients [Internet]. 2016 Jun 8 [cited 2021 Jun 2];8(6). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4924200/
12. Nutrition for sport and exercise – British Nutrition Foundation – Page #1 [Internet]. [cited 2021 Jun 2]. Available from: https://www.nutrition.org.uk/healthyliving/an-active-lifestyle/eating-for-sport-and-exercise.html?start=2
13. BDA. Sport and exercise [Internet]. [cited 2021 Jun 6]. Available from: https://www.bda.uk.com/resource/sport-exercise-nutrition.html
14. Maltodextrin: What Is It and Is It Safe? [Internet]. [cited 2021 Jun 6]. Available from: https://www.healthline.com/health/food-nutrition/is-maltodextrin-bad-for-me#is-it-safe
15. Décombaz J, Jentjens R, Ith M, Scheurer E, Buehler T, Jeukendrup A, et al. Fructose and galactose enhance postexercise human liver glycogen synthesis. Med Sci Sports Exerc. 2011 Oct;43(10):1964–71.
16. Devries MC, Phillips SM. Supplemental Protein in Support of Muscle Mass and Health: Advantage Whey. Journal of Food Science. 2015;80(S1):A8–15.
17. Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? Journal of the International Society of Sports Nutrition. 2017 Aug 22;14(1):30.
18. Banaszek A, Townsend JR, Bender D, Vantrease WC, Marshall AC, Johnson KD. The Effects of Whey vs. Pea Protein on Physical Adaptations Following 8-Weeks of High-Intensity Functional Training (HIFT): A Pilot Study. Sports (Basel) [Internet]. 2019 Jan 4 [cited 2021 Jun 6];7(1). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6358922/
19. Callaway JC. Hempseed as a nutritional resource: An overview. Euphytica. 2004 Jan 1;140(1):65–72.
20. Gorissen SHM, Witard OC. Characterising the muscle anabolic potential of dairy, meat and plant-based protein sources in older adults. Proceedings of the Nutrition Society. 2018 Feb;77(1):20–31.

Contribution from Emily Stynes ANutr and Emily Bowden, ANutr.