11 common protein myths debunked by sports nutrition researchers

Researchers from the International Society of Sports Nutrition lay out what the latest research has to say about 11 common misconceptions concerning protein supplementation.

Hank Schultz, Senior Editor

April 23, 2024

5 Min Read

At a Glance

  • A wealth of research has been done concerning protein supplementation. 
  • Nevertheless, misconceptions and misinformation abound. 
  • A new paper delves into 11 common protein myths to expose the truth. 

Protein supplementation is one of the most thoroughly researched areas in nutrition. Nevertheless, misconceptions about protein abound. A new paper from a prominent research society debunks some of these myths. 

The new research was published last week in the Journal of the International Society of Sports Nutrition and was the work of researchers who are members of the group. The researchers are associated with some of the big names in this field, including Texas A&M University, Nova Southeastern University, Lindenwood University and others. 

Old myths die hard 

The researchers note that misconceptions can creep in over time when an aspect of nutrition and fitness has reached a large swath of the public who are engaged in sharing anecdotal information online. In that situation, sometimes ideas can be cherry picked from past research without sufficient context, leading to skewed conclusions. 

For example, there is a belief that high protein intakes can damage the kidneys, an idea that first was associated with a clinical population of subjects who were already experiencing kidney problems. There is no evidence that larger doses of protein pose any risk to the kidneys of healthy consumers, the ISSN researchers concluded. This was true even in cases of body builders consuming as much as 5 grams of protein per kilogram of body weight a day. For a 185-pound man who also weighs 84 kilos, that would be 420 grams of protein a day. The National Academy of Medicine recommends adult men (not bodybuilders) consume 0.8 g/kg protein a day — between 56-81 grams of protein total.  

Related:5 best ingredients for muscle growth

Or take the issue of protein and bone loss. This arose from something called the “acid-ash hypothesis.” Under this scenario, it was postulated that overconsumption of protein could lead to a buildup of acid in the body, causing excessive excretion of calcium, one of the primary building blocks (along with collagen, a protein) of bones. This idea had already been thoroughly debunked close to 20 years ago, but it still crops up, the ISSN researchers said. 

Does protein make you fat? 

Another myth concerns high protein doses and whether those can make a person fat. There has been information shared that if too much protein is consumed all at once, the excess which can’t be absorbed quickly will automatically be stored as fat. The ISSN researchers said this is entirely dependent on diet and activity. If a person eats too many calories, whether those are from protein or other sources, that excess food energy can be stored as fat. 

That notion presupposed that only so much protein could be absorbed at a sitting.  The ‘ideal’ protein dosage was often given in popular literature as 20 grams with doses of more than 30 grams starting to cross over into the territory where some of that protein could not be absorbed. The ISSN paper makes it clear that there no hard evidence to support an upper limit, with some studies showing doses of even 100 grams at a sitting can be utilized by the body. 

However, there are some foods seen as protein sources which can make you fat, the paper noted. Peanut butter and cheese are often mentioned for their protein content. But that protein comes with large amounts of fat, meaning a person would have to ingest a big slug of calories from fat to get adequate protein from those sources. The paper says those foods are best thought of as sources of dietary fat, not protein. 

Are cheese and peanut butter good choices for protein intake? 

Cheese and peanut butter are among the sources of protein that lacto-ovo vegetarians use. Regarding vegetarianism, the paper notes that it is not true that vegetarians can’t get enough protein in their diet. If they want to build muscle most efficiently, vegetarians do need to pay attention to the amino acid profile of the proteins in their diet, especially in the matter of leucine and essential amino acid content, the researchers noted. 

Other myths explored in the paper include whether red meat ingestion is unhealthy, whether sedentary individuals still need protein, how quickly protein should be ingested post exercise and more. 

11 protein myths debunked 

The researchers summed up their conclusions thusly: 

  1. There is no evidence that consuming dietary protein harms the kidneys of otherwise healthy individuals. 

  2. In exercise-trained men and women, consuming a high-protein diet either has a neutral effect or may promote the loss of fat mass. 

  3. There is no evidence that dietary protein has a harmful effect on the bones. 

  4. Vegans and vegetarians can consume enough protein to support training adaptations. 

  5. Cheese and peanut butter are inadequate sources of protein. 

  6. Red meat does not likely cause unfavorable health outcomes; however, processed meat may cause potential harm (e.g.. increased cardiovascular disease risk). 

  7. Individuals who are not physically active still need dietary protein. 

  8. Protein ingestion following (≤1 hour) resistance training sessions is not an absolute requirement to produce an anabolic environment. What appears more important is the total daily amount of dietary protein consumed. 

  9. Endurance athletes need additional protein (i.e., at least twice the RDA) to assist in a variety of issues related to the adaptive response to exercise. 

  10. One does not need protein powder to meet the daily requirements of exercise-trained individuals. However, treating protein powder differently than typical protein foods (e.g., beef, chicken, milk, etc.) does not make scientific sense. 

  11. For most individuals, consuming 20–30 grams of high-quality protein is sufficient to induce a significant anabolic response; nonetheless, there is data to suggest that 100 grams can elicit a higher and more prolonged anabolic response. 


About the Author(s)

Hank Schultz

Senior Editor, Informa

Hank Schultz has been the senior editor of Natural Products Insider since early 2023. He can be reached at [email protected]

Prior to joining the Informa team, he was an editor at NutraIngredients-USA, a William Reed Business Media publication.

His approach to industry journalism was formed via a long career in the daily newspaper field. After graduating from the University of Wisconsin with degrees in journalism and German, Hank was an editor at the Tempe Daily News in Arizona. He followed that with a long stint working at the Rocky Mountain News, a now defunct daily newspaper in Denver, where he rose to be one of the city editors. The newspaper won two Pulitzer Prizes during his time there.

The changing landscape of the newspaper industry led him to explore other career paths. He began his career in the natural products industry more than a decade ago at New Hope Natural Media, which was then part of Penton and now is an Informa brand. Hank formed friendships and partnerships within the industry that still inform his work to this day, which helps him to bring an insider’s perspective, tempered with an objective journalist’s sensibility, to his in-depth reporting.

Harkening back to his newspaper days, Hank considers the readers to be the primary stakeholders whose needs must be met. Report the news quickly, comprehensively and above all, fairly, and readership and sponsorships will follow.

In 2015, Hank was recognized by the American Herbal Products Association with a Special Award for Journalistic Excellence.

When he’s not reporting on the supplement industry, Hank enjoys many outside pursuits. Those include long distance bicycle touring, mountain climbing, sailing, kayaking and fishing. Less strenuous pastimes include travel, reading (novels and nonfiction), studying German, noodling on a harmonica, sketching and a daily dose of word puzzles in The New York Times.

Last but far from least, Hank is a lifelong fan and part owner of the Green Bay Packers.

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