10 Protein Myths Busted by Real Science
Misinformation about protein is all over the place. Here’s the truth about the mighty macro.
Misinformation about protein is all over the place. Here’s the truth about the mighty macro.
You don’t have to be a bodybuilder to pay close attention to protein. Regarded as one of the building blocks of life, protein is needed for building muscle, immune system function, strong bones, and helping to keep testosterone levels up. This macronutrient gets people talking—but just because people are chatting doesn’t necessarily mean what is getting conveyed is based on scientific evidence. There are a lot of protein myths out there. We’ve got 10 here, but the truth is there are probably hundreds of protein falsehoods out there.
Talk to a handful of people about protein, and the odds are good you’ll hear contradictory statements about everything from protein needs to what sources are best (meat vs plants vs giant tubes of powder) to the role the macro plays in trimming the belly.
There’s so much bogus advice being thrown around in this department that we thought it was a good idea to round up the most common protein myths and set the record straight. Because if you’re not actively looking out for these protein traps, you might end up not getting the most out of this crucial macronutrient.
You would think with all the hype surrounding protein that most people are struggling to get anywhere near enough. But in America, this isn’t the case (1). Most of us eat more protein than is needed.
Calculating your protein intake relative to your weight is better than basing it on the percentage of calories you are eating, as it stays consistent regardless of how many calories you’re packing in.
According to the Dietary Reference Intake report, adults should eat a minimum of 0.8 grams of protein per kilogram of body weight daily. That’s about 60 grams for the average lightly active, 165-pound male. (This calculator can help you figure out your exact needs based on age and weight). It’s pretty difficult to become protein deficient based on this requirement if you eat a varied diet.
But the “right” amount of protein for you depends on many factors, including activity levels and age. If you’re super active hoping to improve your body composition, your ideal range will need to be noticeably higher (2) to support training needs and building new muscle.
The American College of Sports Medicine and Academy of Nutrition and Dietetics recommend 1.2 to 2.0 grams of protein per kilogram of body weight a day for active individuals—that’s between 93 and 156 grams for that same 165-pound frame. If your goal is to put on a lot more muscle mass you’ll want to aim for the higher end of the protein intake range mentioned above.
Research (3) shows that regularly getting about 1.6 grams per kilogram per day promotes favorable muscle adaptations to exercise training. That works out to be about 125 grams per day for our 165-pound guy.
Your protein needs also increase with age, as it becomes more challenging to build and hold onto lean body mass.
While a true protein deficiency is almost unheard of in America (unlike fiber, which almost nobody is eating enough of), most men can benefit from eating more (4) than the bare minimum of the macronutrient to maintain and build lean mass.
As your body changes, your calculations will change along with it. It may take some trial and error to find the level of intake that works best for you based on your goals.
Popular pro-protein diets like Paleo might have you believe that eating heaps of the macronutrient is the magic bullet for weight loss. Unfortunately, that’s not the case and the approach can backfire in the pursuit to keep belly bulge at bay.
Whether they come from beef or brownies, any extra calories beyond what your body requires for metabolic processes can get stored as body fat.
Consuming excess protein may result in you eating too many calories, just as is the case with fat and carbs. Sure, Flintstone-sized steaks can give you bigger biceps—but also a bigger belly.
There is little research to show that you can benefit greatly from eating more than 2.0 grams of protein per kg of your ideal weight. Eating more than that won’t make much difference to the speed at which you gain muscle, but will make a difference to your bank balance, and potentially your waistline, too.
One of the main concerns with overeating protein is that it often means you’re wedging out other healthful items from your diet like vegetables, fruits, and whole grains to make room in your tummy for more of the macro. Do that, and you may fall short on vitamins, minerals, and antioxidants necessary for your body to function at its best.
Also, if you get a big chunk of this extra protein from meats and dairy, it’s easy to go overboard in saturated fat, which could raise your risk for early death (5) from conditions like heart disease and cancer. (6) It’s much harder to stuff in too much protein when eating it from plants because they also come bundled with fiber and there is a limit to how much fiber your gastro tract can handle.
To make protein work harder for you, it’s important to spread intake throughout the day (7). There is a limit (8) to how much protein you can optimally use at once, with the remainder being spillover. One study from the University of Texas found that consuming 90 grams of protein at one meal provides no greater muscle-making benefit than eating a much more modest 30 grams.
To maximize muscle protein synthesis rates and satisfy hunger, space out your protein intake throughout the day (most of us go HAM on protein at dinner compared to breakfast and lunch). An easy rule of thumb: aim to eat roughly 30 grams at each meal.
Getting enough protein at breakfast is important because when you haven’t eaten for hours, muscle protein breakdown is greater than muscle-protein synthesis. Your muscles can only grow and repair themselves when the right building blocks—amino acids from protein—are available in the blood. Eating enough protein at breakfast provides those amino acids and tilts the balance back towards making muscle and away from breaking it down.
When it comes to protein myths, this is one of the biggies. It’s time to move past the bro-mentality that a fondness for tofu over a T-bone steak will give you man boobs instead of chiseled pecs.
Recent research suggests that as long as you meet your overall protein requirements, it does not matter too much if the protein comes from an animal or a plant.
For instance, a recent investigation (9) in the journal Sports Medicine determined that in healthy young males, a high-protein diet (1.6 grams of protein per kilo of body weight) made up exclusively of plant-based foods and soy protein isolate was just as effective at supporting increases in muscle strength and size in response to weight training as did a protein-matched mixed diet made up of animal- and plant-based whole foods along with a supplement of whey protein.
In another study, a 12-week nonrandomized controlled trial (10), 38 subjects performed resistance exercise twice per week. Their diet was high in protein (1.6 g/kg/day) and either omnivorous (meat and plants) or vegan (only plants). In the end, there was no between-group difference in gains in muscle mass size.
More proof that plants can help you sprout bigger muscles: In a 2021 randomized control study (11) in the British Journal of Nutrition, older adults on a high-protein diet saw similar increases in muscle protein synthesis rates whether the protein was mostly from animal sources or entirely from plant sources. And it’s worth highlighting this 2021 study (12) which reported that healthy young men who ingested 40 grams of protein from either chicken breast (175 g) or a meat substitute (230 g) containing wheat and chickpea protein experienced similar muscle protein synthesis rates over the five hours that followed.
That said, it’s often easier to reach your protein intake goal when you include animal-based foods in your diet. For instance, a 3-ounce serving of salmon supplies about 18 grams of protein. You’d have to eat roughly 1 1/2 cups of black beans to get the same amount. Plus, plant-based foods don’t always contain the same amount of protein as the foods they’re substituting.
A five-ounce container of milk-based yogurt can contain 14 grams of protein, while a similar serving size of almond or coconut-based yogurt contains just one gram. So the volume of food required to get enough protein can be higher on a plant-heavy diet, which can result in higher calorie consumption.
If you are following a plant-based diet it’s a good idea to consume multiple different plant protein sources throughout the day to achieve a more balanced profile of the essential amino acids (the ones your body can’t make) necessary for bodily needs including building and maintaining muscle mass. We now know, however, that you don’t have to combine plant proteins perfectly within one meal to form a “complete” protein as long as you get enough of the essential amino acids during the day.
Don’t lose sight of the fact that plant-based proteins like legumes are going to supply you with several beneficial items like fiber and certain antioxidants you will not get from animal-based proteins.
You can’t just feed your muscles what they need to grow; you also need to give them a reason to grow. Resistance training, such as lifting weights, is required for muscle gain.
Your body does need the amino acids in protein sources to better repair or boost muscle mass, but it also needs exercise and strength training to create a situation where the protein has something to work with. That’s why people who don’t stress their muscles have (13) much lower protein requirements.
So sitting on the couch and chugging a protein shake won’t do your physique any benefits if the most exercise you are getting is shaking the shaker cup.
A long-held belief among protein aficionados is that going big on protein stokes your fire to help you win the battle of the bulge. But protein’s impact on your metabolism is far from a fat loss slam dunk.
The thermic effect of food (TEF) represents the energy (the calories) you need to spend to digest, process and metabolize what you eat. Different macronutrients have different TEF. Compared to the 0 to 3% for fat and 5 to 10% for carbs, the TEF for protein is a lofty 20 to 30 percent.
You might think that increasing your protein intake should rev your metabolism, but this is one of the protein myths that needs to die. Evidence (14) hasn’t shown that upping your protein intake results in enough of an increase in TEF to bring on significant weight loss. For instance, if you were to double your protein intake from 15% to 30% of total calories, your daily TEF may only increase by up to 5%. So for every 2,000 calories you consume, your calorie-burning would only raise by an additional 100 calories — a number easily offset by a couple of extra handfuls of chips.
However, eating a generous amount of protein can promote weight loss indirectly by increasing satiety. Protein is the most satiating macro, which is a function of its higher TEF and impact on satiety hormones. Amino acids may also directly impact the brain to promote satiation.
A study (15) in the American Journal of Clinical Nutrition found that individuals who consumed higher protein intakes (ranging from 15 to 50% of total calories from protein) had significantly greater satiety and less hunger in comparison to those who consumed around 14%. This is important because the more quickly you feel full, the less likely you are to overindulge and consume more calories than necessary.
This is one of those protein myths that sounds solid, but lacks context. You may have heard that the so-called “anabolic window” after working out—the short time after training when your muscles are repairing and recovering—is as brief as 30 minutes, and that you need to down protein ASAP after your cool down. But modern science suggests things are more nuanced than that.
After exercise your system is especially primed to process the amino acids from protein, but you need not run straight to your blender to blitz up a protein shake before taking a shower. Your body can still recover after a workout via the protein and other nutrients you eat throughout the day. So instead of worrying so much about what you have immediately following your workout, look at your diet in total and focus on making sure to get enough total protein and also protein that is adequately spread out during the day. Which, yes, can include a post-gym protein shake if you like.
Your kidneys play an essential role in removing waste products such as ammonia associated with the breakdown of protein, so consuming protein above estimated needs does put more work on the organ. This has led some to believe that high protein diets can jeopardize kidney health. While this is true for people who are suffering from impaired kidney functioning (and they should work with their doctor to scale back protein intake, especially animal-based sources), most people don’t have to worry.
For healthy individuals, research shows (16) that higher protein intakes have no harmful effects on kidneys and subsequent higher mortality risk. However, increasing water and fluid intake is recommended to help the kidneys flush out additional waste from extra protein.
Lean protein sources like skinless chicken breasts, extra-lean ground poultry and pork tenderloin are lower in fat and, more specifically, saturated fat than a marbled ribeye. But a moderate amount of saturated fat in your diet is absolutely fine—likely even preferable—to a diet that contains no saturated fat at all. Consider this protein myth busted.
It’s also worth pointing out that not all the fat in meat like a fattier cut of steak is saturated. About half of the fat in red meat is actually unsaturated fat. And the fat in full-fat dairy may not be as detrimental (17) to health as we once thought. Also, fatty fish like salmon cannot be considered “lean,” but they contain important polyunsaturated omega-3 fat.
The truth is that there’s nothing wrong with enjoying some protein sources that are a bit higher in fat, as long as it fits into your total fat, saturated fat, and calorie budget for the day. That likely means including a mix of lean and not-so-lean options in your diet. Your taste buds will also thank you.
Without question, protein powder is an ultra-convenient way to sneak more of this macro into your daily routine in an easily absorbable form. And there are better options than ever on the market, including an uptick in plant-based formulas. But it’s one of the biggest protein myths to think that drinking a shake and eating whole food protein is one-in-the-same.
While powders are a great protein source, it’s one of those protein myths that they they should act as a substitute for whole food sources, both animal and plant alike. Not only do different proteins provide your body with different amino acid profiles, but consuming meats, dairy and plants will also provide your body with essential micronutrients and antioxidants you won’t get from a powder. It should also be stressed that calories in the whole form are more satiating than liquids. That means 200 calories from a chicken breast will quell your hunger to a greater extent than 200 calories from a protein shake which could lead to better overall calorie control.
And one study (18) found that the protein from cheese was just as effective at stimulating post-workout muscle protein synthesis as was a milk-based protein powder. The bottom line: don’t make powders your primary source. Instead, use them as part of an overall protein-sufficient varied diet.