Protein Intake: What’s The Fuss?

4 April 2017
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By the end of 2017, it’s estimated that we would be eating £8 billion worth of protein in the form of shakes, supplements and bars1. With glossy labels flashing words like ‘muscle recovery’, ‘enhanced muscle growth’, ‘lean muscle building’, ‘increased fat burning’, it’s hard to ignore these magical products that promise quick fixes and incredible results (as shown by the ripped torso on the packaging). It’s well established that protein increases muscle mass. So taking more protein should increase your muscle mass, right?

 

How much protein do we need?

Like most things, our bodies are smart enough to get rid of excesses, including protein. So how much is really sufficient? According to the British Dietetic Association, a good estimate of how much protein you need at the minimum to maintain a healthy amount of muscle mass is 0.8-1x your body weight in grams per day.

If you were an endurance athlete the protein intake demands would be slightly higher at 1.2-1.4x, while if you were a strength athlete the demands would be about 1.4-1.7x times their bodyweight in grams. Overall however, people often ignore the fact that the demands for carbohydrates are equally important; otherwise causing the indigested protein to substitute for carbohydrates as the main source of energy.

When should we take it?

Our bodies are only able to cope with 20-30g of protein every 4 hours for promoting muscle synthesis2. So if you think you can get away with bombarding your system with a solid 60g of protein in a single drink, all you would end up doing is peeing pounds away! Many fitness enthusiasts are likely to talk about the ‘anabolic window’ or the time period at which your body is primed to build the greatest amount of muscle and recover.

The anabolic window however is misconstrued to be minutes after you put down a dumbbell, which makes people think that they would have time to take a supplement but not have a proper meal. However in reality, the window is actually much larger and appears to be close to 24-48 hours post exercise3.

To supplement or not to supplement

More recently, there’s been a change in strategy to extend the use of supplements to the general public. As brands modify their marketing strategies to make their supplements more attractive to the larger population, it is even more difficult for us to know what’s really good for us. For example, supplements with similar to what body builders would consume, now claim to promote overall wellness or be an adequate meal replacement.

The truth is, the use of supplements is usually unnecessary, especially considering the diets of people in the west, given most of us are already consuming enough protein on a daily basis without making an explicit effort to do so. A rough estimate of amounts of protein from various foods can be found in the British Dietetics Association pages as illustrated below. From this list we can see that it is not very difficult to get enough protein into our diets.

Research also shows that we can get enough of protein in our diets through balanced meals when compared to taking whey protein after a workout. A simple experiment conducted by the BBC’s Trust Me I’m a Doctor, found that there was no significant difference in knee strength, muscle thickness, total lifting capacity or lean mass (fat free mass) between two groups, where one was given 20g of whey protein and the other 20g of a placebo after resistance training sessions for 8 weeks4.

However, for those of us who don’t consume enough protein, supplements can be convenient and beneficial if they are of good quality, and have the correct amounts of not only protein, but also vitamins, carbohydrates and good fats. It is also worth considering that most supplements do not undergo stringent testing and the 2013 European Supplement Contamination survey found that over 10% of them actually contain banned substances like steroids.

 


So if we do take supplements which ones do we look for?

In a heavily unregulated industry it can be extremely confusing not only to know how to look for the right supplements, but also to ensure that quality standards are high. Of all protein supplements out there, whey protein, being the most heavily researched, is also shown to be the most effective.

The gut absorbs whey, a by-product of the cheese making process more quickly than casein or soy following a bout of resistance training5. By getting into muscles more quickly, it’s able to stimulate muscle synthesis more efficiently than soy or casein.

Proteins are made up of building blocks called amino acids. The reason that whey is metabolised differently is due to the fact that it is made up of a greater proportion of three particular amino acids: leucine, isoleucine and valine, also called branched chain amino acids (BCAAs). These BCAAs are able to stimulate higher muscle protein synthesis at the cellular level and also prevent muscle breakdown after exercise6,7.

Hence, when looking for a good brand of whey protein, a high quantity of BCAA’s, or leucines are often indicative of the quality of the supplement. Typically a good amount of leucine in a protein supplement would be around 3-4g per serving. In comparison, a small chicken breast would contain 2.5g of leucine. Other supplements such as creatine have been shown to have benefits for strength-trained athletes or those who undergo high intensity exercise.

Creatine supplements work differently because creatine itself is not considered to be a protein but exists in high quantities in muscle, and helps to provide energy required to perform repetitions of high intensity movements.

Creatine is naturally found in meat and fish, but our muscles have the potential accumulate a greater amount of creatine than our diets can provide, and hence supplements in this case become a cheap and efficient way of increasing quantities of creatine in our muscles8.

Beware though, as when creatine supplements are taken initially, and levels increase in muscle, so does water retention, resulting in a rapid increase in muscle size initially9 (which is probably why men love these supplements).

Overtime however, as high intensity training becomes more efficient, the increase in muscle size and ‘tone’ most likely comes from fast twitch type II muscle fibres that are more efficient at utilising stored creatine8,10.

Overall, the use of supplements really depends on how much protein you are already consuming in your diet and how much you really need according to your fitness goals (whether aiming for strength or endurance for example).

Since the industry isn’t regulated, it is important to seek advice from qualified dieticians who can recommend which supplements can be trusted. Additionally, the more we can pay attention to labels and what they really mean, the better understanding we will have of what we are eating!

 

References
1. Soteriou, H. Muscle supplement industry going mainstream. BBC News (2011).

 

2. Witard, O. C. et al. Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise. Am. J. Clin. Nutr. 99, 86–95 (2014).

 

3. Schoenfeld, B. J., Aragon, A. A. & Krieger, J. W. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J. Int. Soc. Sports Nutr. 10, 53 (2013).

 

4.Episode 1, Series 4, Trust Me, I’m a Doctor – Will protein supplements help me put on more muscle? – BBC Two. BBC Available at: http://www.bbc.co.uk/programmes/articles/5qYndwd1nyvyFMSynmypy8Z/will-protein-supplements-help-me-put-on-more-muscle. (Accessed: 20th February 2017)

 

5. Tang, J. E., Moore, D. R., Kujbida, G. W., Tarnopolsky, M. A. & Phillips, S. M. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J. Appl. Physiol. 107, 987–992 (2009).

 

6. Norton, L. E. & Layman, D. K. Leucine Regulates Translation Initiation of Protein Synthesis in Skeletal Muscle after Exercise. J. Nutr. 136, 533S–537S (2006).

 

7. Kimball, S. R. & Jefferson, L. S. Signaling Pathways and Molecular Mechanisms through which Branched-Chain Amino Acids Mediate Translational Control of Protein Synthesis. J. Nutr. 136, 227S–231S (2006).

 

8. Buford, T. W. et al. International Society of Sports Nutrition position stand: creatine supplementation and exercise. J. Int. Soc. Sports Nutr. 4, 6 (2007).

 

9. Rl, T. et al. American College of Sports Medicine roundtable. The physiological and health effects of oral creatine supplementation. Med. Sci. Sports Exerc. 32, 706–717 (2000).

 

10. Rawson, E. S. & Volek, J. S. Effects of Creatine Supplementation and Resistance Training on Muscle Strength and Weightlifting Performance.  [Review]. J. Strength 17, 822–831 (2003).