Even if you don’t know anything else about nutrition and fitness, you probably still know that protein intake is a big deal. Protein is a macronutrient that plays a variety of important roles in your body, including helping form different organs and tissues in your body including, yes, your muscle.
So it’s no surprise that athletes and fitness enthusiasts of all levels are so intent on getting enough daily dietary protein for muscle recovery and growth. However, since it’s such an important topic, the concept of protein has also fallen victim to various misunderstandings, outdated information, and plenty of debate over how much we should actually be eating.
Let’s debunk five of the most common protein myths and misconceptions about the fitness world’s favorite macronutrient, and talk about how much protein you actually need to optimize your nutrition intake.
Myth #1: You can only absorb 30 grams of protein per meal.
One of the most common myths about protein is that your body can only absorb a certain amount of protein at any given time (most commonly cited as somewhere in the range of 20-30 grams of protein per meal). But this is simply not true: the fact of the matter is, while the quality of your protein source can influence its rate of digestion, virtually all of the protein that you eat can actually be absorbed by your body. So even if you eat a really high-protein meal that ranks at 100 grams of protein, your body will absorb almost all of it.
But the kicker here: “absorption” is not the same thing as “usage for building muscle,” and it’s important to make a distinction between the two.
In nutrition science, the term “absorption” describes the amount of protein that makes it from the food you eat into your circulatory system after digestion. But not all of that protein is used for muscle growth, and the amount that does will depend on your weight and fitness level.
In other words, your body may absorb the entirety of the aforementioned 100 grams of protein that you ate, but some of it will go to other physiological processes like energy production.
Case in point: one study estimated that the benefits of protein consumption for bodybuilders “maxes out” somewhere between 0.4-0.6 g/kg of body weight over the course of three-six meals a day. Translated to pounds, that would be somewhere between 0.18-0.27 g/lb of body weight, meaning that someone who was about 180 lbs might benefit most from getting about 30-50 grams of protein per meal. Again, they would absorb virtually all of the protein they ate even if they ate above this threshold -- but the excess would go to other bodily processes.
Myth #2: You absolutely NEED 1g of protein per pound of body weight to gain muscle.
Some fitness buffs swear by the formula of eating 1 gram of protein per pound of their body weight to make gains. To be fair, there isn’t anything inherently bad about eating 1 gram of protein per pound of your body weight. In fact, 1 gram of protein can certainly help you build muscle if that’s your end goal.
But 1 gram of protein per pound is simply too high for many people who aren’t used to eating that much protein, and you don’t actually need to consume that much to gain muscle.
Instead, there’s plenty of scientific evidence that points towards a slightly lower protein recommendation: about 0.7-0.8 grams per pound of body weight. Research has shown that this is a sufficient amount of protein to eat per day for maximizing muscle protein synthesis, even among high-level athletes. Again, higher levels of protein consumption aren’t bad either (the same research saw that higher protein consumption had its own merits, especially when cutting fat) but it isn’t a necessity.
The key here isn’t to just load up on as much protein as you can -- instead, it’s to get enough high-quality protein and total calories per day for muscle synthesis. Going above and beyond by eating an extraordinarily high amount of protein doesn’t necessarily translate to more muscle-gaining benefits, so more isn’t always better in this case.
Myth #3: Protein damages your kidneys.
Another protein absorption myth is that protein can damage your kidneys when you have too much of it, which means that many people find themselves hesitating to get the appropriate amount of protein for fear of causing organ failure or other serious complications.
This idea may come from the fact that protein digestion results in the production of urea in order to get rid of excess nitrogen.,our kidneys are in charge of filtering out urea from your blood and excreting it through the urine. In addition, some observational studies have found an association between kidney function decline and high-protein diets.
But the truth of the matter is that there isn’t a ton of good clinical evidence to support the idea that high protein consumption is harmful to your liver, as long as the person is healthy to begin with and doesn’t have any pre-existing issues with their kidneys.
For example, this 2016 crossover trial study evaluated the effects of very-high protein consumption on the kidney function of healthy, resistance-trained adults who already ate diets fairly high in protein to begin with. The participants ate their regular amount of protein (2.6 g/kg of body weight) each day for eight weeks, then switched to a high protein intake of 3.3 g/kg for another eight weeks. Researchers took measurements of various health biomarkers throughout, including measurements indicative of kidney function like glomerular filtration rate, creatinine, albumin, and blood urea nitrogen levels. The researchers found that there were no differences in kidney function between the participants’ consuming “normal” and “high” protein diets!
Another strong argument is that even though the participants had high protein intake at baseline (~2.6g/kg of body weight), they did not present with dysregulated kidney function at baseline.
A major caveat here, though, is that we’re referring to adults who are healthy and have no pre-existing kidney issues. Someone who already has issues with their kidneys may not be able to handle a high-protein diet; in cases like this, it’s best to consult with your doctor.
Myth #4: Supplemental protein is different from protein from food.
Another common myth about protein that often gets perpetuated in the health and fitness spaces is that protein powder is somehow more dangerous than protein found in whole food sources and that you should limit the amount of protein powder you consume per day. Let’s unpack this.
The idea that whole foods are “better” than supplements has its merits in that whole foods also generally include more nutrients that aren’t in concentrated nutrition supplements like protein shakes. But when it comes to protein itself, the protein found in supplements is the exact same kind of protein that’s found in its whole food counterpart -- it’s just more concentrated.
There are certainly different kinds of protein found in different food sources. For example, whey protein, which comes from the whey component of milk, is a complete protein, meaning it has all essential amino acids that your body can’t make on its own. Meanwhile, pea protein is an incomplete protein, meaning that it does not have all nine essential amino acids. So the actual source of protein does matter, and there’s evidence that animal protein may be superior to plant proteins when it comes to making gains. Given that caveat, as long as you eat a sufficient amount of total protein and consume from a wide variety of sources, animal-based doesn’t seem to be better than plant-based.
At the end of the day, the protein that you’re getting from your whole food source is the same type of protein that you’re getting in your protein powder, whether it’s whey, casein, pea, soy, et cetera.
Myth #5: Protein makes you bulky or overly muscular.
The last protein myth that puts people off from adding more to their diet is that it can make you bulky, especially for women or for people looking to achieve a more lean, cut physique. If you’re concerned about getting “too big” from taking a sports nutrition supplement, rest assured: that protein shake isn’t enough on its own to make this happen.
We’ve already established here that protein is an important piece of the dietary puzzle for repairing muscle tissue and spurring growth. But huge, “bulky” muscles are not solely the products of weightlifting and/or protein consumption. You’ve also got to factor in genetics, hormones, and total calorie consumption, and years of hard training.
Let’s look at the hormone issue, for example. Testosterone, a sex hormone, is present in both men and women, but much more so in men. Testosterone is also hugely important for muscle growth and maintenance. While estrogen, one of the primary sex hormones in women, is also anabolic, this can contribute to very different kinds of muscle growth in men vs. women.
Another thing: there’s evidence that eating a high-protein diet in conjunction with exercise can actually increase both muscle growth and fat loss. In other words, when paired with the right exercise plan, people actually often find themselves looking leaner and more athletic!
The bottom line here: adequate protein intake can absolutely help you gain muscle mass when combined with the right diet and exercise regimen, but it isn’t likely to make you bulky in and of itself.