Macronutrients 101: Protein

How to elevate your health and performance with protein

Protein is arguably one of the most “popular” macronutrients, especially in the sports world. But how does protein actually help to elevate health and performance, and how much do you actually need?

There are many types of proteins in the body, and they have a variety of functions:

1. Structural function: as the major structural component of muscles and other tissues like collagen, keratin and elastin, protein can be seen as the “building blocks” of the body.
2. Hormones: hormones are proteins that act as chemical messengers in the body. A widely known example is the hormone insulin, which helps to transport carbohydrates into cells to be used for energy.
3. Enzymes: proteins also form enzymes that participate in various metabolic processes in the body.
4. Immunity: proteins form the antibodies and immunoglobulins that make up the immune system in the body.
5. Energy: protein can be oxidised for energy, although this is a bit more of a “metabolically expensive” process than the use of carbohydrates for energy.

Different types of protein consist of unique sequences of amino acids, the small “building blocks” of protein molecules, of which 20 is identified up to date. The human body needs all 20 identified amino acids for proper growth and development on a day-to-day basis.

Non-essential amino acids are those that our bodies already have a supply of or we have the ability to make them on our own. Essential amino acids are those that we must gather from the foods we eat. Conditional amino acids are only essential during times of severe stress or trauma like surgery, medical illness, etc.

Amino acids, protein types and athletes

The International Society of Sports Nutrition recommends that high-quality proteins should be incorporated into an athlete’s diet. The nutritional value of a protein is determined by its unique amino acid profile – proteins with a high biological value (HBV) are recommended wherever possible. The 9 essential amino acids that needs to be obtained from food, and if a protein source contains all 9 amino acids it is called a “complete protein” or HBV protein. Animal based proteins such as dairy foods, eggs, meat, fish and poultry are considered HBV proteins, and plant sources of complete proteins include buckwheat, quinoa and soy. Other plant based proteins only contain only some of the essential amino acids are considered to be of lower biological value.

A note about plant-based amino acids

Even though plant-based sources of protein does not contain all the essential amino acids all at once, it is possible to obtain all the amino acids from eating a variety of plant sources:

• Most grains tend to be low in lysine and high in methionine
• Most legumes tend to be low in methionine and high in lysine

Note: you do not necessarily need to eat these two food groups in the same meal. As long as you consume both sources in the same day consistently, you will have all the amino acids your body needs to function properly.

What’s the deal with BCAA’S?

Branched chain amino acids, isoleucine, leucine, and valine, are essential amino acids, but they differ in structure from the other amino acids. They are also unique in the sense that they can be oxidised by muscles for fuel.

These amino acids can help to prevent muscle breakdown during exercise, and are beneficial after exercise by stimulating muscle synthesis and promoting recovery. They may also be benefit athletes during recovery from injury by limiting muscle wasting/atrophy associated with immobilization/decreased training.

Often, you see athletes in the gym drinking a BCAA supplement – however, consuming these amino acid during exercise does not necessarily increase the benefits on muscle recovery and synthesis if the total amount consumed in the diet is adequate. Consuming more BCAA’s than your body needs also does not lead to more benefits.

There are a variety of food sources of BCAA’s, which should be your first go-to option for BCAA’s as food sources have other benefits that helps to elevate muscle recovery, synthesis and overall health as well. Foods such as dairy, eggs, poultry and fish are rich in BCAA’s or you could combine plant-based sources such as soybeans, lentils, almonds, cashews, or chickpeas to get the amount of BCAA’s your body needs.

Leucine and athletes: the muscle builder

Leucine, one of the branched chain amino-acids, are especially of importance as it plays a critical role in ‘switching on’ muscle protein synthesis. Research suggests that ~2-3g of leucine maximally stimulates protein synthesis (this is about ~20-25g of complete protein).

Dairy products, beef, poultry, seafood, pork, peanuts, beans, lentils, and soybeans are among the foods richest in leucine. Of the plant-based proteins, soy foods are the best sources of leucine (more information on soy in the “myth busting” section).

Distribution and servings of protein

A recent article in the Journal of Nutrition found that muscle protein synthesis increased with 25% when protein was evenly distributed across breakfast, lunch, and dinner compared to consuming the most protein at dinner.

In the International Society of Sports Nutrition Position Stand: protein and exercise the researchers concluded that the recommendations of optimal protein intake per serving for athletes to maximize muscle synthesis are mixed and depend on age and recent resistance exercise. The current recommended dose of protein per meal are 0.25 – 0.4g of a high-quality protein per kg of body weight, or an absolute dose of 20–40g. This should ideally be consumed every 3 – 4 hours.

Pre-sleep protein and muscle synthesis

Studies has shown that taking in protein before you go to bed provides increased muscle protein synthesis and metabolic rate without affecting the process of fat breakdown. The recommended dose is about 30 – 40g, and the type of protein used in the studies are casein protein, a type of slow- release protein found in dairy products.

Protein and athletes

Athletes require more protein than non-exercising individuals for muscle repair and tissue synthesis. The amount you need is very individual, and current nutritional science recommendations are based on grams per kilogram.

Note that protein should not be increased at the expense of carbohydrates, especially in endurance athletes, as this may impact performance in a negative way. For carbohydrate recommendations, read the “Carbohydrates 101”post here.

Post workout protein

A lot of people talk about “the anabolic window”, but what does this actually mean? “Anabolism” is simply the process of building tissues in the body. According to the ISSN the optimal time period during which to get in protein depends individual tolerance, since benefits are derived from pre- or post-workout intake; however, the anabolic effect of exercise is long-lasting (at least 24 h), but likely decreases with time post-exercise. The less recovery time you have between sessions (for example, 2-a-days) the more important speedy intake of both carbohydrates and proteins are after exercise.

One study on cyclists found that adding protein (0.4 g/kg/h) to carbohydrate (0.8 g/kg/h) within 2 hours of completing an initial exhaustive bout of cycling exercise led to a significant increase in cycling performance the next morning when compared to eating just carbohydrate, thus suggesting that protein combined with carbohydrate post-exercise leads to better recovery.

International Society of Sports Nutrition protein recommendations

Goals/context	Recommendations	Example: A 70kg athlete’s needs
For building and maintaining muscle mass	1.4–2.0 g protein/kg body weight per day (g/kg/d).	70kg x 1.4g = 98g per day 70kg x 2g = 140g per day For building and maintaining muscle mass this athlete needs 98 – 140g protein per day
To minimise the loss of lean body weight in resistance trained individuals during periods of severe calorie deficit (e.g. bodybuilders who are preparing for a show)	2.3–3.1 g/kg fat-free mass per day *note that this is fat free mass, therefore you need to subtract the amount of fat in kg from total weight to use this range.	70kg athlete with 15% body fat: 70 x 15% = 10.5kh Fat free mass: 70 – 10.5kg = 59.5kg 59.5kg x 2.3 = 137g 59.5kg x 3.1 = 185g Therefore this athlete needs 137 – 185g protein per day.
Post workout	Intakes of carbohydrate and protein (3:1 ratio) within 2 hours are shown to be beneficial
Amount of protein per dose (meal/snack)	0.25 – 0.4g of a high-quality protein per kg of body weight, or an absolute dose of 20–40 g every 3-4 hours.	70kg x 0.25g = 17.5g 70kg x 0.4g = 28g This athlete needs 17.5g – 28g protein per day.

In the ISSN exercise & sports nutrition review update: research & recommendations it is also noted that higher protein intakes (> 3.0 g protein/kg body weight/day) when combined with resistance exercise may impact body composition positively in resistance trained athletes (i.e., promote loss of fat mass). However, note that protein intakes should never be at the expense of the other macronutrients, especially carbohydrates, because this will impact performance negatively. Protein and overall macronutrient intakes should be tailored according to your individual goals and training, and the season of training that you are in.

As you can see, the ranges of protein needs are quite wide, and your true needs are very individual. If you want someone to help you calculate your needs and monitor your response as well as translate the science to food sources, I highly recommend going to a dietitian to help you with this.

Are supplements necessary?

This depends on your goals and training. It is more than possible to get adequate protein from your diet, and in most cases protein supplementation are not necessary. The decision to use a protein supplement should be based on several factors, including your training load, goals, daily energy requirements, typical diet, appetite post-exercise, and budget.

Myth: Collagen is a good source of protein.

If you constantly opt for collagen as protein source, it could negatively impact serotonin by not getting enough tryptophan. If you want to add collagen, it would need to be in addition to meeting your daily protein needs.

Myth: Excess protein “leaches” calcium from bones.

Hypotheses from the 1920s about excess protein leaching calcium from bones have been proven wrong. Although Calcium excretion increases as protein intake increases, so does calcium absorption, leading to no net loss in calcium. Protein makes up about ½ of bone volume and 1/3 of its mass.

Myth: Soy is bad for you.

Fact: The origins of this myth come from one of the phytochemical types in soy, isoflavones, which also are phytoestrogens—plant compounds that weakly mimic the effect of the hormone estrogen.

Soy-based foods are excellent sources of protein, iron, calcium and healthy fats.

Soy contains relatively little saturated fat and is associated with a reduced risk of a number of chronic diseases.

Unfortunately, the popular media frequently refer to studies that are either inapplicable to humans, inconclusive or of unacceptable quality to support soy’s harmful effects.

No negative effect was found on testosterone according to a meta-analysis out of the Fertility & Sterility journal.

There was no measurable estrogenic or androgenic effect following soy supplementation in male college age students according to a recent study of the Scientific Reports journal.

A big myth is that women should avoid soy because it increases their risk of breast cancer. However, in most cases, consuming soy products may in fact be protective against breast cancer.

CONCLUSION

Protein is an important macronutrient for athletes. Ensuring that you are getting adequate total quantities of protein as well as individual amino acids is important in order to elevate your health and performance. When possible, choose whole-foods sources of protein as they come packaged with other nutrients and substances like micronutrients, fibre and phytochemicals that can have further benefits for the body and performance.

References

Aragon AA, Schoenfeld BJ, Wildman R, Kleiner S, Vandusseldorp T, Taylor L, Earnest CP, Arciero PJ, Wilborn C, Kalman DS, Stout JR, Willoughby DS, Campbell B, Arent SM, Bannock L, Smith-Ryan AE, Antonio J. 2017. International society of sports nutrition position stand: diets and body composition. Journal of the International Society of Sports Nutrition. 14(16).

Kerksick C, Harvey T, Stout J, et al. 2008. International Society of Sports Nutrition position stand: nutrient timing. Journal of the International Society of Sports Nutrition. 5(17). Available from: http://www.jissn.com/content/pdf/1550-2783-5-17.pdf

Phillips SM, Van Loon LJC. 2011. Dietary protein for athletes: from requirements to optimum adaptation. Journal of the International Society of Sports Nutrition. 29(Suppl 1):S29–38.

Hamilton-Reeves JM, Vazquez G, Duval SJ, Phipps WR, Kurzer MS, Messina MJ. 2010. Clinical studies show no effects of soy protein or isoflavones on reproductive hormones in men: results of a meta-analysis. Fertility and Sterility. 94 (3):997-1007

Yan L., Spitznagel, E.L. 2009. Soy consumption and prostate cancer risk in men: a revisit of a meta-analysis. American Journal of Clinical Nutrition. 89(4):1155-63.

Haun, Cody T.; Mobley, C. Brooks; Vann, Christopher G.; Romero, Matthew A.; Roberson, Paul A.; Mumford, Petey W.; Kephart, Wesley C.; Healy, James C.; Patel, Romil K.; Osburn, Shelby C.; Beck, Darren T.; Arnold, Robert D.; Nie, Ben; Lockwood, Christopher M.; Roberts, Michael D. 2018. Soy protein supplementation is not androgenic or estrogenic in college-aged men when combined with resistance exercise training. Scientific Reports. 8(1):1-9.