Written by Aoife Corr
Protein is an essential macronutrient needed for many functions within the body. There are many myths and misconceptions regarding protein, that always seem to be circulating. This blog will hopefully debunk some popular protein myths and help you build a positive relationship and position for protein in your diet.
- Protein’s main role is to build muscle
This is a myth. Protein is in fact needed for so much more within the body. Proteins are made up of chains of amino acids, and have many functions.
Those functions include providing a structural framework for the transport and storage of molecules, to act as enzymes, and for the synthesis of various hormones such as glucagon, melatonin and thyroid hormone. Protein is also needed for growth and development and to help your body to repair cells.
While protein is needed to build muscle, it is important to remember that it is only one of its many vital roles within the body.
- Too much protein can cause kidney disease
This is a myth. Consuming too much protein can be harmful if there is a pre-existing liver/kidney damage or dysfunction. Protein recommendations of up to 2.0g/kg body weight is not harmful to otherwise healthy individuals.
Current recommendations are 0.8g/kg bodyweight for the general public (although it has been debated if this is really sufficient) and 1.2-2.0g/kg body weight for athletes. It is important to note that the main concern regarding high protein diets with athletes is that other nutrient intake might be compromised, which can have an adverse effect on performance. There really is no need to be consuming more than these levels. However, it is important to try to reach your protein intake through dietary sources such as meats, legumes and dairy, first and then use supplements as the last element of your diet.
- Protein is needed immediately after exercise.
Protein timing has been widely debated recently with some research pointing to the fact that overall daily protein consumption is more important than the timing of protein intake immediately after exercise. However, consuming protein after exercise is still important for adequate muscle repair and definitely won’t hinder any progress. In particular, protein ingestion prior to sleep stimulates muscle protein synthesis rates during overnight recovery. To summarise, absolute daily protein intake is more important, but for those consuming high levels of protein they probably do need to consume it immediately after training as otherwise they will not have sufficient time to consume what they require throughout the day [1].
- Animal protein is better than plant protein
Animal based protein sources such as meat, dairy, fish and milk proteins (whey and casein), are considered to be ‘complete’ protein sources. Which means they contain all 9 essential amino acids. However, plant based protein sources such as legumes, rice, tofu and soy products are still excellent protein sources. In terms of exercise, studies have indicated that whey protein is the optimal protein source to support muscle hypertrophy when coupled with resistance training [2], however that shouldn’t be a reason to switch to whey protein if you are following a vegan diet. Furthermore there are huge environmental implications associated with animal protein sources.
- The more protein you consume the better
This is a myth. Consuming more than 2.0 g/kg body mass of protein per day has no added benefits, and ultimately would be a waste of money. The body has a limited capacity to store protein, so when you consume protein in excess of what is required, it is oxidised and stored as fat. Intakes higher than 2.0 g/kg body mass per day may be needed during periods of higher intensity training or when reducing energy intake, but this is generally aimed at well-trained athletes [3].
In conclusion, I believe everyone, not just those who exercise, should be consuming adequate protein, preferably above the RDA of 0.8g/kg body mass, to support optimal bodily function and overall health.
References
- Schoenfeld, B.J., A.A. Aragon, and J.W. Krieger, The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr, 2013. 10(1): p. 53.
- Devries, M.C. and S.M. Phillips, Supplemental Protein in Support of Muscle Mass and Health: Advantage Whey. Journal of Food Science, 2015. 80(S1): p. A8-A15.
- Thomas, T., K.A. Erdman, and L.M. Burke, Nutrition and Athletic Performance. Medicine & Science in Sports & Exercise, 2016. 48(3): p. 543-568.