Protein powders are one of the most popular supplements around and are taken religiously by gym-goers worldwide. But what are they? Do they work?

This article will look at the benefits and possible side effects of the most popular form of protein powder, whey protein.

What are proteins?

Proteins are large molecules composed of amino acids, they make up muscle and tissue and produce hormones, enzymes and haemoglobin.

They can also be used for energy when broken up into amino acids (called catabolism).

However the body prefers to use carbohydrates for energy as it is quicker.

We get a lot of protein in our diet, (especially if you follow a typically western diet) from either animal sources (dairy, eggs, meat etc) or vegetable sources.

Protein powders

The amount of protein as a percentage of our diet is typically below 20%. To improve this, protein powders have become increasingly popular with the general population.

There are many forms of protein powder available at the moment, you can have protein powders derived from egg, rice, soya, or milk, to name a few.

A milk based protein

Whey protein is a milk based protein that is a by-product from the production of cheese. Milk is around 87% water; the remaining 13% is made up of 30% fat, 37% lactose, 27% protein and 6% minerals. The available protein is 20% whey and 80% casein. The whey protein is isolated from the casein and then dried out into a powder.

Both Whey and Casein are high quality proteins with high levels of branch chain amino acids compared to vegetable proteins which tend to have less essential amino acids and are known as incomplete sources of protein.

Benefits of Whey protein

There are numerous benefits to supplementing with whey protein.

Protein builds and repairs muscle post exercise so if you’re training it is advantageous to increase the amount of protein you consume.

Rankin found that consuming milk post workout (which contains both whey and casein) increased fat-free mass when compared to consuming a carbohydrate drink.

Whey protein side effects_2Protein prevents injury

Protein can also help prevent injury by preventing chronic inflammation.

Whey protein might actually lower C-reactive protein (a protein created in the liver in response to a tissue injury but which is also created in response to exercise).

Whey protein has also been found to reduce blood pressure, improve immune function, lead to fat loss (when combined with resistance exercise) and lower glucose in people with type 2 diabetes when taken before a carbohydrate based meal.

Protein powders are convenient!

The benefits of taking a protein shake are that they are very convenient, you can pack a shaker in your gym bag or take it to work. It just needs water adding to it, and without the water the powder can be easily transported with minimum fuss.

Plus, there is no need to keep it refrigerated, and the best before date is rarely an issue due to the long shelf life.

Calorie control

Whey protein powder is also fast digesting especially when compared to food, and it is also useful for people who are on calorie controlled diets.

This is because the macronutrients are standard and the calorie estimation is accurate.

You can have whey protein powders that are low fat/low carb or low fat/high carb. You can also use milk instead of water to increase fat, carbs and protein.

However, Whey protein can have some negative side effects as well. Tomorrow in Part Two of the article I’ll tell you the potential dangers of using whey protein and also provide some tips and advice on how to choose the best protein powder for you.

Connect with Expert Matthew Smith


[1] Hoffman, J., Falvo, M. 2004. Protein – Which is best? Journal of Sports Science and Medicine 3: 118-130

[2] Fulgoni, V. 2008 Current Protein Intake in America: analysis of the National Health and Nutrition Examination Survey, 2003-2004. American Survey for Clinical Nutrition 87(5): 15545-15575

[3] Naclerio, F., Alkhatib, A., Jiminez, A. 2013. Effectiveness of Whey Protein Supplement in Resistance Trained Individuals. Journal Sports Medicine & Doping Studies 3(3): 1-7

[4] Rankin, J., Goldman, L., Puglisi, M., Nickols-Richardson, S., Earthman, C., Gwazdauskas, F. 2004. Effect of post-exercise supplement consumption on adaptations to resistance training. Journal of the American College of Nutrition 23(4): 322-30

[5] Zhou, L., Xu, J., Rao, C., Han, S., Wan, Z., Qin, L. 2015. Effect of whey supplementation on circulating C-reactive protein. a meta-analysis of randomized controlled trials. Nutrients 7(2): 1131-1143

[6] Pal, S., Ellis, V. 2010 The chronic effects of whey proteins on blood pressure, vascular function, and inflammatory markers in overweight individuals. Obesity 18(7): 1354-9

[7] Daly, J., Reynolds, J., Sigal, R., Shou, J., Liberman, M. 1990. Effect of dietary protein and amino acids on immune function. Critical Care Medicine 18(2 Suppl): S86-93

[8] Hulmi, J., Laakso, M., Mero, A., Hakkinen, K., Ahtiainen, J., Peltonen, H. 2015. The effects of whey protein with or without carbohydrates on resistance training adaptations. Journal of the International Society of Sports Nutrition 16(12): 48

[9] Ma, J., Stevens, J., Cukier, K., Maddox, A., Wishart, J., Jones, K., Clifton, P., Horowitz, M., Rayner, C. 2009 Effects of a protein preload on gastric emptying, glycemia, and gut hormones after a carbohydrate meal in diet-controlled type 2 diabetes. Diabetes Care 32(9): 1600-2

[10] Berardi, J., Andrews, R. 2013. The Essentials of Sport and Exercise Nutrition 2nd ed. Precision Nutrition, Inc. p165

[11] Pennings, B., Boirie, Y., Senden, J., Gijsen, A., Kuipers, H., Van Loon, L. 2011 Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men. The American Journal of Clinical Nutrition 93(5):997-1005

[12] Tang, J., Moore, D., Kujibida, G., Tarnopolski, M., Phillips, S. 2009 Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. Journal of Applied Physiology 107(3): 987-92


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