Vasts amounts of information exist on protein and protein supplements as it relates to health and fitness. As such it can often be confusing to separate fact from fiction. This article will review the top 9 protein myths and uncover the truth about this beneficial macronutrient.
Myth 1. Proteins Aren't Different From One Another
Supplemental protein can come from a variety of sources. The most common being whey, casein, egg, and plant. Each type has its own unique benefits such as varying digestion rates and essential amino acid profiles. Depending on an individual’s goal one protein may work better than the other. For example, whey proteins digest and absorb rapidly which make it the ideal protein source to take either pre or post exercise to promote muscle growth and recovery. On the other hand, casein is an ideal before bed protein source as it provides a slow release of amino acids that inhibit protein breakdown. Milk proteins also have the added benefit of having the highest leucine content, the primary driver of muscle protein synthesis, compared to other sources. In the middle of the digestion spectrum is egg proteins. Egg protein may be a good option for individuals who are lactose intolerant and experience bloating and gastric distress with whey. Additionally, egg if often thought of as an ideal protein source because its amino acid profile has been used as the standard for comparing other dietary protein. Lastly, plant-based proteins may be the best choice for vegetarians and vegans. Although the protein quality is not as high compared to other sources, plant proteins such as pea, rice, and hemp generally provide all the essential amino acids needed by the body to repair, recover, and rebuild.
Myth 2. High Protein Diets/Protein Powder Makes You Fat
Eating more calories than you burn, not consuming supplemental protein, is the main culprit behind this myth. In general, when calories in are greater than calories expended you will start to see changes in body composition. Supplementing with protein can actually have the opposite effect. Several research studies have demonstrated that individuals who eat a high protein diet lose body fat while simultaneously losing weight. This is more than likely due to protein’s thermic effect (requires more calories to digest) and it’s ability to promote a feeling of fullness. To further debunk this myth, a 2015 study found subjects who consumed a high protein diet (4 times the recommended daily allowance) that included supplemental protein powder did not experience any unfavorable changes in body composition or performance.
Myth 3. 30 Grams of Protein is the Maximal Amount That Can Be Absorbed by the Body In One Sitting
The theory behind this myth stems from the research showing that muscle protein synthesis (MPS) is maximized when 20-30 grams of protein is consumed and that going above this amount does not have a greater effect on MPS. While this is true, a recent study debunked this myth showing without a doubt that the body can absorb and utilize more than 20-30 grams at one time even though it did not stimulate MSP to a greater degree. The additional protein consumed in the study (70 grams total) was shown to improve whole body protein synthesis by reducing muscle protein breakdown. Whether this equates to larger improvements in muscle growth and repair is yet to be proven, but it does demonstrate that eating more than 30 grams of protein in one meal or snack can be utilized by the body.
Myth 4. Protein Must Be Consumed In the Anabolic Window to Have Any Benefit
Most individuals are familiar with the term “anabolic window”; the 30-60 minutes post workout when muscle are supposedly in an ideal state to utilize protein for growth and recovery. In the past, many experts agreed that forgetting to feed with protein during this window would impair training adaptations. However, an emerging body of evidence suggests this anabolic window may last several hours after finishing a workout. While it is still important to consume a post workout protein shake to maximize MPS synthesis when it is at its highest; what is more vital is to eat enough total protein on a daily basis to maintain a positive nitrogen balance and keep MPS elevated. It is recommended that strength training individuals shoot for 1.4-2 grams of protein per kilogram bodyweight daily and eat a high protein meal every 3-4 hours.
Myth 5. Your Kidneys Will Be Destroyed By A High Protein Diet
This is the most common protein myth of them all. The theory states when a high protein diet is consumed the kidneys are forced to work harder to expel the additional nitrogen which then leads to kidney damage. While this myth may be true for individuals with a pre-existing kidney issue; it is entirely untrue for the majority of people. In fact, no piece of scientific literature written in the past 100 years has demonstrated that a diet high in protein has any adverse effects on kidney health. To further discredit this myth, a 2015 study conducted at Nova Southeastern University found no harmful effects on kidney function when researchers had subjects consume three times the suggested RDA for protein on a daily basis for six months.
Myth 6. Eating High Amounts of Protein Without Exercise Can Cause Muscle Growth
While this myth may have a small amount of truth to it, the fact is a high protein diet works best in conjunction with a dedicated strength training program. This is especially true when lean mass growth and recovery are paramount. Without adequate amounts of protein, the body may utilize the available amino acid pool for repair and other bodily functions instead of growth. While eating more protein without training will not help you pack on muscles; it may help individuals lose a few extra pounds and body fat. This is due to the thermic and satiating effect of protein.
Myth 7. Protein Causes Gas
Gas resulting from protein consumption usually results from one of two things. First, milk intolerant individuals may experience flatulence when consuming a whey concentrate due to the higher amounts of lactose; in which case the remedy is to switch to a whey isolate that contains little or no lactose. Second, people who are not lactose intolerant may experience gas when protein shakes are a sole source of nutrition. In this case, it is advised to eat a more well-balanced diet to relieve any GI distress
Myth 8. Protein Supplements Cannot Be Considered Real Food
Protein powders and bars contain many of the same ingredients as “real” food such as milk and eggs. They also usually provide vitamins, minerals, and the other macronutrients in one convenient product. These products, as the names imply, are meant to supplement the diet, and help individuals with higher protein needs meet their daily requirements. Protein supplement should never entirely replace whole food sources, but nonetheless, they are still “real” food.
Myth 9. Osteoporosis Can Be Caused by High Protein Diets
High protein diets were once thought to increase calcium excretion and be detrimental to bone health. Fortunately, this is not the case. In fact, diets high in protein have been shown to increase calcium absorption and have no negative impact on bone calcium stores. On the contrary not getting enough protein can be deleterious to bone health. Case in point a 2003 study found people with chronic low protein intake were at a greater risk for lower bone density and more bone loss.
- Witard, O. C., Jackman, S. R., Breen, L., Smith, K., Selby, A., & Tipton, K. D. (2014). Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise. The American Journal of Clinical Nutrition, 99(1), 86-95.
- Kim, I. Y., Schutzler, S., Schrader, A., Spencer, H. J., Azhar, G., Ferrando, A. A., & Wolfe, R. R. (2015). The anabolic response to a meal containing different amounts of protein is not limited by the maximal stimulation of protein synthesis in healthy young adults. American Journal of Physiology-Endocrinology and Metabolism, ajpendo-00365.
- Dawson-Hughes, B., Harris, S. S., Rasmussen, H., Song, L., & Dallal, G. E. (2004). Effect of dietary protein supplements on calcium excretion in healthy older men and women. The Journal of Clinical Endocrinology & Metabolism, 89(3), 1169-1173.
- Kerstetter, J. E., Kenny, A. M., & Insogna, K. L. (2011). Dietary protein and skeletal health: a review of recent human research. Current Opinion in Lipidology, 22(1), 16-20.
- Bonjour, J. P. (2005). Dietary protein: an essential nutrient for bone health.Journal of the American College of Nutrition, 24 (sup6), 526S-536S.
- Munger, R. G., Cerhan, J. R., & Chiu, B. C. (1999). Prospective study of dietary protein intake and risk of hip fracture in postmenopausal women. The American Journal of Clinical Nutrition, 69(1), 147-152.
- Rizzoli, R., & Bonjour, J. P. (2004). Dietary protein and bone health. Journal of Bone and Mineral Research, 19(4), 527-531.
- Additional reference regarding the “anabolic” window