11 common protein myths debunked by sports nutrition researchers

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 bodybuilders 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.  

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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: