Firstly, what is protein and why do we need it?
Protein is one of the three major macronutrients. It makes up part of the structure of every cell and tissue in the body, including muscle tissue, internal organs, skin, hair and nails. Protein is needed for the growth and formation of new tissues, to repair tissue and to regulate many metabolic pathways.
There are 20 amino acids and these are the building blocks of all proteins. Of these, there are 12 amino acids that can be made in the body; these are called non-essential amino acids (NEAA). The other 8 are called essential amino acids (EAAs) because they cannot be made into the body and must be obtained through the diet in food sources. The current recommended protein intake for the general population is 0.75g/kg BW/day and for athletes it is a little higher at 1.2-2g/kg BW/day. The additional protein requirements for athletes is needed to compensate for the increased breakdown of protein during intense training sessions to repair and recover muscle tissue after training.
To maximize muscle protein synthesis (MPS), it is best to consume 0.25g of protein per kg BW in every meal. It is best to distribute protein intake throughout the day and not have all your protein in one meal. Aim to consume ‘high quality’ protein that contains all eight EAAs and are easily digested and absorbed, like milk and eggs, as these are the best type of protein source. Milk is a brilliant recovery food too for muscle repair and to reduce post exercise muscle soreness and DOMS.
Protein supplementation
Protein supplementation comes in a few different forms, including protein powders, shakes and bars. Some of these contain whey protein, casein, milk , egg, soya or non dairy sources. They are designed to provide a concentrated source of protein. Whey protein comes from milk and contains high levels of EAAs, therefore these are easily digested and absorbed. Casein is also derived from milk but is slower digested but still has high levels of all the EAAs.
Some studies have shown that consuming either a whey or casein supplementation after resistance training raises blood levels of amino acids and promotes MPS. Other research has shown athletes who consumed a whey protein supplement before, during or after resistance training for a determined length of time (6-10weeks), achieved a greater increase in muscle mass and muscle strength compared to those who took a placebo.
Overall, consuming high quality protein sources after resistance training will promote muscle repair and growth. Whey supplementation may be a better post exercise option compared to casein or soya because whey is absorbed quicker.
So is protein supplementation really necessary?
It still remains questionable whether supplements are necessary to increase muscle mass and strength or if you can get enough protein from food sources. The American College of Sports Medicine (ACSM) suggests that protein requirements can be met through diet alone without the use or protein supplements. However protein supplementation may be beneficial if you have higher protein requirements (e.g. for athletes weighing over 100kg like bodybuilders).
The main benefit of protein supplements is that they are convenient and many come in the form of a bar, cookie, shake drink or gel. They are portable, easy to consume and the perfect on the go protein source. There are no side effects of taking protein or consuming more than you require. Although the opinion of some is that more protein is better, there is no evidence that high daily intake of protein will result in further muscle mass and strength gains. Ultimately, consuming more protein than you need will likely have no advantage to your health or physical performance.
Are protein supplements better than food sources?
Many studies highlight that protein supplements are not necessarily better than a protein food source. Protein food sources like milk have been found to be just as effective as supplements. There is no evidence that protein supplements improve performance or promote recovery better than food sources. If you are consuming a wide variety of foods containing protein, there may be no need to take a protein supplement. A wide variety of food means you are getting a better balance of amino acids and other nutrients like fibre, vitamins, minerals and carbohydrates.
In summary, protein is an essential nutrient and has many functions in the body. High quality proteins are easily digested and absorbed and protein intake should be distributed throughout the day. Protein supplementation is a concentrated source of protein and comes in many forms like a powder, drink, bar or gel. Protein supplementation may be beneficial if you have higher protein requirements, however, protein requirements can be met through diet alone without the use or protein supplements. There is no benefit to health or physical performance if higher intakes of protein are taken daily.
References
Bean, A,. 2017, Complete Guide to Sports Nutrition. [S.I]: Bloomsbury Sport
Candow, D. G et al (2006), ‘Effect of whey and soy protein supplementation combined
with resistance training in young adults’. Int. J. Sports Nutr. Exerc. Metabo,. Vol. 16, pp.
233-44
Rodriguez, N. R., Di Marco, N. M., Langley, S., et al. (2009), ‘American College of
Sports Medicine position stand:Nutrition and athletic performance’, Med. Sci. Sports
Exerc. Vol 41(3), pp 709-31