Nutrients play different roles in our bodies. Macronutrients (carbohydrates, fats, and protein) all have varying & different functions. This article will discuss/debunk several myths associated with protein, what I sometimes refer to as the “master macronutrient” because it is involved in so many bodily functions! Protein, which is made up of amino acids, is an essential nutrient which means we need to consume it because we do not make it on our own. Protein interacts with muscle, bone, skin, hair, and just about every tissue in the body. It is required for structural support (muscle and bone maintenance), optimal immune function, and is important in helping our recovery from challenging workouts! 

Protein helps us stay feeling full which may be beneficial if someone has a goal of intentional weight loss. It is also a key component of an athlete’s diet as protein is vital for recovery from training. Oftentimes, we hear a lot of claims against protein but these claims have often been debunked. Below, we will decipher 4 common claims. 

Myth: High-protein diets may cause kidney damage in healthy adults

In healthy individuals, eating a high protein diet will not harm or affect kidney function. Many studies have suggested high protein consumption has no influence on glomerular filtration rate (GFR) in individuals that do not have chronic kidney disease. GFR is one of the markers that indicate kidney function.

Myth: High-protein diets are bad for bones

No, protein is not bad for our bones. In fact, higher protein intake may have a protective effect on bone mineral density (BMD) compared with lower protein intake when calcium intake from your diet is normal. Therefore, eating a higher protein diet has no adverse effects on bones and may even benefit bone density. The folks making claims saying “high protein diets leach calcium from bones” are not correct.

Myth: Individuals older than 65 should not consume higher protein

It is natural for our bodies to lose muscle mass, strength, and function that progressively occurs with aging. This is known as sarcopenia. Getting enough protein can help older adults protect their muscle mass and quality of life. It is recommended that older adults need a minimum of 1-1.2 grams of protein per kilogram body weight, and if they are active, they likely need more.

Myth: A high-protein, high-calorie diet will help you lose weight a.k.a. "eat as much protein as you want and you won’t gain weight”

If your caloric intake is greater than your energy expenditure it doesn't matter how much protein you eat, it will not help you lose weight. A high protein diet and a calorie restricted diet will help you lose weight.  Also, if your protein choices are not lean sources/are too high in fat, you may be consuming calories in excess, which can lead to weight gain.  

How much protein should we be eating?

The  International Society of Sports Nutrition (ISSN) (has an excellent position stand linked in the references for your reading) suggests that an overall daily protein intake in the range of 1.4-2.0 g protein/kg body weight/day (g/kg/d) is sufficient for most exercising individuals. The current RDA (recommended dietary allowance) is 0.8g/kg to PREVENT DEFICIENCY, which one can argue is NOT OPTIMAL.

Conclusion

If someone is healthy (specifically does not have kidney or liver issues), studies show they can safely consume greater than 0.8 g/kg of protein and in fact may benefit from a higher intake. Always consult with a registered dietitian and your primary care provider prior to making drastic changes to your lifestyle, including diet & exercise to ensure your safety. 

References

  1. Devries, M. C., Sithamparapillai, A., Brimble, K. S., Banfield, L., Morton, R. W., & Phillips, S. M. (2018). Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets: A Systematic Review and Meta-Analysis. The Journal of nutrition, 148(11), 1760–1775. https://doi.org/10.1093/jn/nxy197 
  2. Tsagari A. (2020). Dietary protein intake and bone health. Journal of frailty, sarcopenia and falls, 5(1), 1–5. https://doi.org/10.22540/JFSF-05-001 
  3. Baum, J. I., Kim, I. Y., & Wolfe, R. R. (2016). Protein Consumption and the Elderly: What Is the Optimal Level of Intake?. Nutrients, 8(6), 359. https://doi.org/10.3390/nu8060359 
  4. 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., Smith-Ryan, A. E., Stout, J. R., Arciero, P. J., Ormsbee, M. J., Taylor, L. W., Wilborn, C. D., Kalman, D. S., Kreider, R. B., Willoughby, D. S., Hoffman, J. R., … Antonio, J. (2017). International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition, 14, 20. https://doi.org/10.1186/s12970-017-0177-8