Protein is a crucial nutrient, but with so much conflicting advice out there, it can be hard to know exactly how much you should be consuming. Athletes need more, but how much more? Is there such a thing as too much protein?
What is protein and why is it important?
Proteins are made up of chemical ‘building blocks’ called amino acids. 20 amino acids can be used to synthesise proteins in humans. Among these 20 amino acids, the body cannot synthesise 9, therefore dietary intake is essential. Essential amino acids include phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, leucine, and lysine.
Your body uses amino acids to build and repair muscles and bones and to make hormones and enzymes. They can also be used as an energy source.
Quantity vs. quality of protein
It should be noted that substantial differences exist between the quality and the amount of protein from various protein sources. Protein quality is just as important as protein quantity. Protein quality is an overall measure of the ability of a protein source to meet the metabolic demand and is defined in terms of biological value (i.e. the fraction of amino acids absorbed by the gut from food that is subsequently retained by the body)
Animal-based proteins are generally accepted as high-quality proteins owing to better essential amino acid profile and higher digestibility (approximately 100) compared to plant-based proteins (ranging from 80 to 85).
Amino acids (building blocks of protein) and/or combinations of amino acids regulate physiologic processes. The relationship of amino acids to one another can enhance/negate certain physiological outcomes. A sole focus on total protein intake rather than a proportional ratio of amino acids to meet specific physiological conditions is a misnomer. Due to the metabolic demands of various physiological stages/states, i.e. maintenance, muscle tissue growth, power, endurance and recovery, a specific amino acid profile is needed to support and optimize these physiological processes. A habitual diet providing enough protein can still be deficient/limiting in specific amino acids. Therefore, your diet should not only focus on providing enough protein, but also on providing adequate proportional amounts of specific amino acids exactly what PVM’s Beyond Protein Blends does!
Research confirms that a combination of various time-releasing proteins stimulates growth more effectively than a fast-releasing single protein source, such as whey. Therefore, Fusion Mass and Protein XTR includes a combination of various time releasing proteins such as egg-albumen, casein and whey proteins that provide an immediate and sustained availability of amino acids.
How much protein do you need?
| Recommendation | Source |
|---|---|
|
0.8 g/kg/day
This means a 70 kg person should consume at least 56 g of protein daily. With age (>65 years old) this amount increases to 1 – 1.2 g/kg/day. |
Recommended Dietary Allowance (RDA) for protein, set by the National Academy of Sciences |
|
Energy intake should come from carbohydrates (45%-65%), protein (10%-35%), and fats (20%-35%).
For active individuals, they recommend 5-12 g of carbohydrates/kg body weight and 1.2-1.8 g of protein/kg body weight, depending on activity level. |
The Institute of Medicine (IOM) |
| Athletes should consume 1.4–2.0 g/kg/day of protein to build and maintain muscle mass | The International Society of Sports Nutrition (ISSN) |
| Our recommendation for athletes is between 1.5 – 2.2 g/kg/day depending on your specific goals (weight loss, maintenance or increase in lean mass) and sport type. | Combination of sources including IOM and ISSN. |
What if I eat too little/too much protein
Too little protein can lead to:
- Muscle loss, weakness, headache, and physical fatigue
- Reduced endocrine hormone production (insulin, growth hormones, and thyroid hormones)
- Growth stunting in children and impaired development
- Impaired immune function, frequent infections
- Impairments in absorption, transport, and storage of nutrients (including vitamins, minerals, amino acids, glucose, and fatty acids)
- Swelling (particularly in the abdomen, legs, hands, and feet)
- Hair breakage, pale skin, and dry or flaking skin
Although an upper safe level for protein intake is still being debated; there are short-term studies that have shown healthy, active adults can safely consume >2.2 g/kg/day of protein. However, these studies are usually no longer than 2 weeks making it difficult to accurately measure the long-term effects of high protein diets. More long-term studies are needed.
Take note that; consuming too much of any nutrient, including protein, is harmful to your health. Higher protein intake should not be prioritised above sufficient intake of carbohydrates and fats. The main sources of energy in the human body. Often protein intake is prioritised and insufficient carbohydrates are consumed to the detriment of optimal training, recovery and performance. The excessive use of protein as an energy source is detrimental to performance and health.
Where do protein supplements fit in
It’s often difficult and expensive for athletes with higher protein requirements to meet their needs with food only. Good quality protein sources such as lean fish, chicken and meat (without bone or fat) only contain between ± 20 -30 % of protein by weight. A 100 kg rugby player requires 150-200 g of protein daily, which equates to consuming 680 – 900 g of cooked lean mince daily.
Powdered protein products are convenient and, depending on the product, can be cost-efficient for athletes with higher protein requirements.
Table 1 below gives the protein and energy values of different quality protein sources.
| Food | Protein/100 g | Energy/100 g |
|---|---|---|
| Beef, fillet, cooked | 30.9 g | 803 kJ (192 kCal) |
| Beef, Mince, lean | 22 g | 700 kJ (167 kCal) |
| Beef, Rump, cooked | 29.2 g | 1125 kJ (269 kCal) |
| Biltong, beef, lean | 40.3 g | 1312 kJ (314 kCal) |
| Biltong, game | 52.4 g | 1093 kJ (261 kCal) |
| Boerewors, cooked | 13 g | 1624 kJ (388 kCal) |
| Cheese, cheddar | 24.7 g | 1646 kJ (394 kCal) |
| Chicken breast, cooked | 29.4 g | 633 kJ (151 kCal) |
| Chicken, dark meat, cooked | 24.1 g | 789 kJ (189 kCal) |
| Chicken, meat and skin, cooked | 25.6 g | 917 kJ (219 kCal) |
| Egg, whole boiled | 12.6 g | 616 kJ (147 kCal) |
| Fish, hake, steamed | 20 g | 427 kJ (102 kCal) |
| Fish, tuna, canned in brine | 25.5 g | 463 kJ (111 kCal) |
| Milk, full fat, fresh | 3.2 g | 262 kJ (63 kCal) |
| Ostrich, cooked | 25.4 g | 262 kJ (63 kCal) |
| Pork, loin, grilled | 27.3 g | 978 kJ (234 kCal) |
| 978 kJ (234 kCal) | 978 kJ (234 kCal) | 978 kJ (234 kCal) |
| PVM Fusion Mass | 44.0 g | 1646 kJ (392 kCal) |
| PVM Protein XTR | 75.0 g | 1541 kJ (368 kCal) |
| Yoghurt, full cream, plain | 4.2 g | 416 kJ (99 kCal) |
| Yoghurt, low fat, plain | 4.3 g | 254 kJ (61 kCal) |
References:
- protein intake. Advances in Nutrition, 12(1), pp.71-88.
- Wolfe, R.R., Rutherfurd, S.M., Kim, I.Y. and Moughan, P.J., 2016. Protein quality as determined by the Digestible Indispensable Amino Acid Score: evaluation of factors underlying the calculation. Nutrition reviews, 74(9), pp.584-599.
- Nishimura, Y., Højfeldt, G., Breen, L., Tetens, I. and Holm, L., 2023. Dietary protein requirements and recommendations for healthy older adults: a critical narrative review of the scientific evidence. Nutrition research reviews, 36(1), pp.69-85.
- Jäger, R., Kerksick, C.M., Campbell, B.I., Cribb, P.J., Wells, S.D., Skwiat, T.M., Purpura, M., Ziegenfuss, T.N., Ferrando, A.A., Arent, S.M. and Smith-Ryan, A.E., 2017. International society of Sports Nutrition position stand: protein and exercise. Journal of the International Society of Sports Nutrition, 14, pp.1-25.
- Phillips, S.M., 2014. A brief review of higher dietary protein diets in weight loss: a focus on athletes. Sports medicine, 44, pp.149-153.
- Phillips, S.M., Chevalier, S. and Leidy, H.J., 2016. Protein “requirements” beyond the RDA: implications for optimizing health. Applied Physiology, Nutrition, and Metabolism, 41(5), pp.565-572.
