We’ve heard it before—protein is key to building lean body mass. Moreover, protein is a macronutrient similar to carbohydrates and fats in the sense that we need to consume it in larger amounts compared to other nutrients, such as vitamins and minerals. Ample dietary protein provides a host of benefits and is essential to normal body functioning. Here are some key roles listed below:
- Provides essential amino acids (the building blocks of all body tissues/organs/hormones/enzymes)
- Supports immune function and DNA synthesis
- Supports lean muscle mass maintenance and growth
- Aids in exercise recovery
- Aids in wound and injury healing
- Promotes satiety and reduces hunger
- May support weight loss/maintenance
- Contributes to a healthy, balanced diet
- Helps slow the absorption of carbohydrate-rich foods to produce a stabilizing effect on blood glucose levels
- Can be utilized for energy when carbohydrate/fats/calories are insufficient (survival mechanism)
The Recommended Daily Allowance (RDA) which is a recommendation set to meet the needs of 97.5% of the healthy population, suggests that adults consume 0.8 g/kg protein per day. The Acceptable Macronutrient Distribution Range (AMDR) which is the percentage of daily calories coming from each macronutrient, is set at 10-35%. Now you may wondering what accounts for this large range? Well, higher protein intake is required by specific groups, such as those who engage in exercise—specifically resistance training. This number can vary between 1.2- 2.0 g/kg of body weight per day based on individual differences.
This is because when we exercise, muscle is continuously being broken down and built up in a process known as “protein turnover”. Therefore, it only makes sense that we need to replenish our source of protein and ensure there is ample to support new muscle.
In fact, exercise and nutrition research shows that if you are just at the beginning of your resistance training journey, you may require even higher protein needs than someone who has been training longer. This number is suggested to be as high as 1.6-1.7 g/kg/day.
Why?Because new lifters have been found to have a higher muscle protein synthesis rate (can gain muscle faster) than their well-trained counterparts, and as time goes on, our muscles become more adapted. Studies suggest that it is at this point that protein requirements of trained individuals can be dropped slightly, perhaps to 1.4 g/kg, while still achieving the same results as if they were consuming a higher protein intake.
It is clear that protein is essential to normal bodily functioning and supports muscle growth, so make sure you are getting enough in your diet and from a variety of sources, including fish, poultry, legumes, nuts, and whole grains. And remember, just because you eat more protein, doesn’t necessarily mean you will gain more muscle, especially if you are an experienced lifter. Like carbohydrates and fats, protein still provides calories, so consumption of any macronutrient beyond your body’s energy needs will still contribute to weight gain. Ensuring you are consuming a balanced intake of dietary protein, fat, and carbohydrate is essential to overall health. Finally, there is no one ideal number you need to hit, rather your protein requirements should align with your individual needs and goals.
Dietary reference intakes. The essential guide to nutrient requirements. (2006). Otten, J., Hellwig, J., Meyers, L. (Eds.). Washington, USA: National Academies PressDietary Reference Intakes: The Essential Guide to Nutrient Requirements
IOC. (2016). Nutrition for Athletes: A practical guide to eating for health and performance. Prepared by the Nutrition Working Group of the Medical and Scientific Commission of the International Olympic Committee.
Morton, R. W., Murphy, K. T., McKellar, S. R., Schoenfeld, B. J., Henselmans, M., Helms, E., . . . Krieger, J. W. (2018;2017;). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 52(6), 376. doi:10.1136/bjsports-2017-097608
Schoenfeld, B. J., Aragon, A. A., & Krieger, J. W. (2013). The effect of protein timing on muscle strength and hypertrophy: A meta-analysis. Journal of the International Society of Sports Nutrition, 10, 53-53. doi:10.1186/1550-2783-10-53
Writer: Kelly Chen