25 Myths and Facts About Protein [FAQ]

Do you have questions about protein you want answers to? Like how much you should eat, when you should eat it, and what’s best protein is? Do you want to separate the protein myths from the facts?

So do I, and that’s why I wrote this FAQ. In this article, you’ll find answers to most, if not all, questions you might have about protein and building muscle. In addition, I dispel tired old myths in favor of current scientific research and evidence.

Without any further ado, let’s jump straight into it!

What is Protein?

Protein is the building material of your body! Every cell in your body depends on protein to work properly. The protein in your organs and your muscles are constantly being broken down and synthesized. That process is called protein turnover. Your body needs protein to repair and build itself up. Also, without enough protein, you won’t see the gains you want from your efforts in the gym.

When you eat, you give your body the protein it needs to do all that. After a protein-rich meal, your digestive system breaks the protein down into amino acids, and these travel to the parts of your body in need of repair and construction work.

What are Amino Acids?

Amino acids are molecules used to build protein. The protein in your body and in the foods you eat consists of chains of amino acids. When you digest a meal, you break down those chains into free amino acids, which you then use to build new protein in your organs and muscle.

Free amino acids vs protein
Free amino acids form different proteins.

There are 20 amino acids in the protein you eat, and they are classified into two groups: essential and non-essential amino acids. You need to get the essential amino acids from your diet, but your body can make the non-essential ones when it needs them.

You need all the essential amino acids to build muscle, but you only have to provide the essential ones through your diet. If, for some reason, you don’t get enough of the non-essential ones from the food you eat, your body takes care of them for you. However, all the protein you eat provides you with all 20 amino acids, and you usually don’t have to think about the non-essential.

In alphabetical order, the nine essential amino acids are as follows:

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

The list of non-essential amino acids looks like this:

  • Alanine
  • Arginine
  • Asparagine
  • Aspartic acid
  • Cysteine
  • Glutamic acid
  • Glutamine
  • Glycine
  • Proline
  • Serine
  • Tyrosine

What is Protein Balance?

Your protein balance is the balance between the rates of synthesis and breakdown of protein. Whole-body protein balance takes everything that is not fat in your body into account, while most people engaging in strength training are interested in muscle protein balance.

Want to build muscle? Then you want a positive muscle protein balance. In other words, your muscle protein synthesis needs to exceed your muscle protein breakdown. Not constantly, but over a day, a week, or longer, your muscle protein synthesis has to be greater than your muscle breakdown for your muscles to grow.

Both muscle protein synthesis and muscle protein breakdown are constants every second of your life. Sometimes your muscle protein balance is positive; other times, it is negative. You gain muscle, and you lose muscle. No one walks around in an anabolic state all the time. The important thing is a positive protein balance over time. The shorter the time we’re looking at, the less important it is.

In the fasting state, your muscle breakdown always exceeds muscle protein synthesis. Once you eat a meal, you stimulate muscle protein synthesis, and your muscle protein balance switches to positive. This process goes back and forth, up and down, day after day, year after year.

I Want a Positive Protein Balance! How Do I Get One?

If you’re healthy, relatively young, and you don’t overeat or undereat, the highs and lows of your muscle protein balance, as illustrated in the diagram below, even out over time. Your body weight is stable, and you neither lose nor gain muscle mass. If you’re strength-training regularly, the peaks become a little higher, leading to a slow and steady gain of muscle mass.

This picture shows what your muscle protein balance looks like during a day without training:

Muscle protein synthesis and breakdown over the day.

The dotted line is your muscle protein synthesis, and the green line is your muscle protein breakdown. When you go without food, you build less muscle, and your muscle breakdown increases. After a meal, your body flips the switch and starts building muscle, and your muscle breakdown decreases.

Exercise, especially strength training, increases your protein turnover. Both the peaks and the valleys in the diagram above become larger. In other words, exercise makes you both build and break down more muscle tissue. Exercise boosts your muscle protein synthesis more, but your muscle protein synthesis can’t exceed your muscle protein breakdown if you don’t eat. In the fasted state, you lose muscle. Lifting weights fasted makes you lose less muscle, but you don’t start gaining until you eat something, and that something is protein. Strength training + protein is like the imaginary equation 1 + 1 = 3 and a sure-fire combination leading to muscle growth over time.

protein synthesis and breakdown

For at least 24 hours after a workout, your muscles are extra sensitive to the protein you eat, which means that you build more muscle every time you eat if you lift weights regularly.

How Much Protein Do You Need?

Current dietary guidelines for Americans recommend that protein make up 10–35% of your daily calorie intake.1 If you eat 2,000 calories per day, for example, and 20 % of those are protein calories, you’d eat 100 grams of protein per day.

That amount of protein gives you all the essential amino acids you need for health and performance. Eating a regular mixed diet, you need at least 0.8 grams of protein per kilogram of body weight per day to stay healthy and keep your muscle mass.

If you want to build muscle, you need a little more. You want to get between 1.4 and 2 grams of protein per kilogram of body weight and day.2 A recent review of the available research found that 1.6 grams of protein per kilogram of body weight per day are the limit where the average person does not build more muscle by eating even more protein.3

However, the average person is just that: average. Some people can use even more protein to build muscle, maybe even up to 2.2 grams per kilogram of body weight per day. If you want to be sure you get enough, aiming for 2 grams of protein per kilogram of body weight per day or even a little more is probably a good idea. Eating “too much” protein does no harm, but it does give you a comfortable headroom even if you’re not one of the lucky few able to use it all for muscle-building purposes.

Do You Need More Protein On a Weight-Loss Diet?

Yes! Your protein requirements go up when your food intake goes down, especially if you’re strength training and aim to keep or even gain muscle during your diet. When you burn more calories than you eat, you likely need a whopping 2.3–3.1 grams of protein per kilogram of fat-free mass per day to do so.4 Note that this particular review uses fat-free mass to calculate your protein needs, not total body weight, which is by far the most common way to do so. It’s a bit trickier to use fat-free mass instead of body weight since you need to know how much body fat you’re carrying around.

Let’s say you weigh 80 kilograms with 15% body fat. You simply multiply 80 with 0.85 to get your fat-free mass in kilograms, 68 kilograms in this case. Fat-free mass is everything in your body except for, you guessed it, fat. The 80-kilogram example person needs around 2.6 grams of protein per kilogram of body weight per day when going by total body weight.

Can You Only Use 20–30 Grams of Protein From a Meal?

No, you absorb and use pretty much all the protein you eat. Claims that you pee it out if you eat more than that are nonsense and a myth. You only see traces of protein in the urine of a healthy person, even after a hefty protein-rich meal.

However, you can’t use unlimited amounts of protein to build muscle. Your body still uses the protein to build and repair other tissue, but you won’t benefit from gigantic protein feedings for building muscle.

You don’t need to stuff yourself with protein every meal to build a maximal amount of muscle. If you eat 30 grams of protein, you’ll max out your muscle protein synthesis the following hours, at least if you’re not fresh from the gym. Eating 90 grams of protein in a single meal does not build more muscle than eating 30 grams.5 That’s if you eat a high-quality protein like meat or eggs. If you only eat plant-based proteins, the numbers are probably a little higher. You need more plant protein per meal to build as much muscle as you would from animal protein sources.

Do you need more protein than usual after a workout? That’s would be logical, right? However, that doesn’t seem to be the case. After a workout, your muscles become more sensitive to amino acids, and a smaller amount of protein seems to stimulate your muscle protein synthesis maximally.

If you train one or two muscle groups, you max out your muscle protein synthesis with as little as 20 grams of high-quality protein, like egg or whey protein, after the workout.6 7 Eating more than that does no harm, but you don’t build more muscle either. You use the excess as energy.

If soy protein is your post-workout protein of choice, you need 26 grams to get the same effect as with 20 grams of whey protein. Less qualitative protein sources, meaning protein with fewer essential amino acids, require even larger servings. For example, if you use oat protein, pea protein, or wheat protein, you’d likely need 40–50 grams of protein at once for an excellent muscle-building effect.

After a full-body workout, you can use more protein for building muscle. The upper limit for muscle protein synthesis then becomes at least 40 grams.8 Don’t expect double the muscle growth from double the protein, though. We’re only talking around 20% greater muscle protein synthesis, a classic case of diminishing returns.

After a run or some other type of endurance training, the same principles apply. Around 30 grams of high-quality protein, like milk protein, stimulate your muscle protein synthesis maximally after cardio.9 Fifteen grams is too little, and that amount barely stimulates muscle protein synthesis more than no protein at all. 

As an older lifter, you should probably aim for 40 grams of protein after a workout, no matter what your workout looks like. More is better after 50–60 years of age if you want to build muscle and grow stronger.10 11 12 As we get older, we need more protein to build as much muscle as we did when we were young.

Read more: How Much Protein Per Meal Can You Use to Build Muscle Mass?

What Happens if You Eat Too Much Protein at Once?

With “too much,” I mean more than you use to build muscle, not that it’s harmful.

Even if you don’t build more muscle by eating more than 30 grams of protein per meal, it’s not a complete waste to do so. More than 30–40 grams of protein in a single meal is also anabolic, increasing protein synthesis and decreasing protein breakdown. “Too much” protein isn’t too much for everything.

It’s not all about muscle protein synthesis.

Instead of stimulating muscle protein synthesis more, eating a large serving of protein builds other tissues than muscle. Your liver and other organs, your intestines, and the cartilage in your joints all use the protein you eat for maintenance and repair. That’s not a bad thing at all. Also, they can release amino acids for your body to use as needed if you don’t eat as much protein some other time.

In addition, large protein-rich meals decrease protein breakdown. Not necessarily muscle protein breakdown, but the overall protein breakdown in your whole body.13

Older individuals who like to eat a lot of protein-rich food in the same sitting have an advantage here. Unlike young people, you do build more muscle if you eat a lot of protein all at once. These are entirely new findings. New research shows that a whopping 70 grams of protein from a single meal improve both muscle and whole-body protein balance in the elderly, compared to 35 grams.14

Does It Matter if You Eat All Your Protein in One or Two Big Meals, or Is It Better to Spread It Out?

You already know that you can’t use unlimited amounts of protein from a single meal to build muscle. Also, a single meal does not stimulate muscle protein synthesis for too long, not more than a handful of hours. That means that it’s probably better to spread your daily protein intake reasonably evenly over the day.

Eating all your protein in one or two large meals works fine, though. Thousands of athletes with excellent physiques do intermittent fasting, only eating during a few hours of the day.

However, suppose you want optimal returns from your efforts in the gym. In that case, you’ll probably benefit from several moderate servings of protein during the day instead of stuffing yourself once or twice.

According to current recommendations, the best way to give your muscles the building materials they need is to spread your protein intake reasonably evenly over the day, maybe every 3–4 hours.15 Eating 0.4 grams of protein per kilogram of body weight per meal seems like a good strategy.16

Do you prefer eating a few larger meals instead of multiple smaller ones? Go ahead! You can build muscle and strength that way too. Also, an eating pattern you enjoy is probably superior in the long run. It’s perhaps a little better to spread your protein intake out over the day, but the difference is probably not significant enough to motivate forcing yourself to do so if you don’t enjoy it.

Do You Build More Muscle if You’re Constantly Eating or Drinking Protein?

The answer is no. Your muscles react to sudden and large amounts of amino acids appearing in your blood, like when you eat a protein-rich meal or drink a protein shake. Suppose you keep pouring amino acids into the system, keeping your blood amino acid levels constantly high. In that case, muscle protein synthesis drops down to normal levels, even though you give your muscles what they need. 

This effect is called “muscle full,” While there is no clear consensus about its importance, letting the amino acid levels in your blood drop between meals might make each meal more anabolic.17 18 19 The 3–4 hour interval between meals mentioned earlier is likely a good choice for this purpose as well.

Do You Need More Protein as You Get Older?

Yes, you do, both over the day as a whole and on a per-meal basis.

Seniors need 1.1 to 1.3 grams of protein per kilogram of body weight per day for optimal muscle function, compared to the 0.8 grams usually mentioned for young people.20 There are no specific recommendations for older lifters looking to gain muscle, but 2–2.2 grams of protein per kilogram of body weight per day feels like a good idea. That gives most young lifters a little more than they actually need and should be a reasonable amount for older ones to aim for.

As you age, your muscles start to respond a little less to the protein you eat. Each meal results in a little less new muscle protein than in the good old days. Don’t worry too much, though. You can compensate for this phenomenon simply by eating a little more protein per meal. What’s an older lifter, you might ask? Science can’t put an exact number on it, and the point in life where it becomes a measurable thing likely varies between individuals. Somewhere around the age of 60, perhaps.

If you want to read more about the protein needs for the older lifter, feel free to check out my in-depth article Building Muscle as You Age: Protein Needs for the Older Lifter.

Protein Quality, What’s That?

A high-quality or complete protein provides enough amino acids you need to build muscle and other tissues. Proteins of lower quality, or incomplete protein, are lacking in one or more amino acids. Those are called limiting amino acids.

In general, all animal-based proteins, like dairy, meat, poultry, fish, eggs, and so on, give you enough of every single amino acid. Plant-based proteins are more problematic. Except for soy protein, vegetable proteins have limiting amounts of at least one amino acid.

Fortunately, your body is smart enough to combine amino acids from different protein sources. If one protein source gives you too little of one amino acid, you automatically take that amino acid from something else and combine them. Your body can even combine amino acids from different meals. The average person doesn’t have to think about getting high-quality protein from every meal. The body handles everything on its own. No studies look at someone trying to build as much muscle as possible, though. However, as long as you don’t base your diet on one or two low-quality protein sources, you should be good to go. If you regularly eat animal-based protein, you don’t have to think about it at all.

A couple of proteins, like collagen and gelatin, contain so little of the essential amino acids that you can’t use them to build muscle. Biological value (BV) is a common way to measure protein quality, with a BV of 100 being a perfect protein. You can eat half as much protein with a BV of 100 compared to a BV of 50 and still build as much muscle. Collagen and gelatin have a BV of 0, meaning they are pretty much useless for your muscles.

Collagen is interesting in that you use it to build connective tissue and cartilage instead, potentially improving joint health and even reducing arthritis pain.21 22 Low-quality for muscle-building purposes doesn’t have to mean useless for everything else.

How Much of the Protein You Eat Ends Up as Muscle?

Not much. Only 10–15% of the amino acids in the protein you eat or drink end up as muscle protein.23 What happens to the rest? You use it to build and repair protein in other tissues. Your heart, liver, gut, skin, intestines, cartilage, and so on – they all depend on protein for maintenance and function. Anything left over after that oxidizes to energy.

Then why should you eat 2 grams of protein per kilogram of bodyweight if only a few grams turn into muscle? Do you only build 10 grams of muscle per day if you eat 100 grams of protein?

Good question! 

The protein you eat is not the only source of protein for your muscles. You have another significant source: your muscle protein. As mentioned before, you both build and break down muscle all the time. Muscle breakdown might sound like something you’d rather avoid, but your body is smart. Broken down muscle protein doesn’t just disappear. You recycle 75% of the amino acids liberated by muscle breakdown. They then respond to the levels of amino acids in your blood after eating a protein-rich meal, and your body uses them to build new, fresh muscle tissue.

That’s why it’s helpful to eat more protein than you directly use for muscle-building purposes. After eating or drinking protein, your blood amino acids levels start to rise. Before long, they are high enough to send signals telling your body to start building muscle. The amino acids ending up as muscle protein doesn’t have to come from the protein you just ate, as you recycle amino acids from muscle breakdown as well.

What’s Special About the Amino Acid Leucine?

Leucine is one of the essential amino acids. More specifically, it’s the critical amino acid triggering muscle protein synthesis. When enough leucine enters your bloodstream, your body responds by turning on the muscle protein synthesis switch. The more leucine you get from a meal up to a point, the greater the muscle protein synthesis you trigger. That point is somewhere around 3 grams of leucine per meal.24

To get 3 grams of leucine, you need to eat or drink 28 grams of whey protein, 37 grams of potato protein, 38 grams of casein protein, 43 grams of egg protein, or a massive 50 grams of wheat protein.

Leucine content of various foods. Clinical Nutrition Open Science, Volume 36, April 2021.

Do You Have to Worry about Muscle Breakdown?

In most cases, no. Let’s get into why.

Muscle protein synthesis is not the only thing that decides if you gain muscle. There is also muscle protein breakdown, which goes on 24/7 as well. The balance between synthesis and breakdown determines if you gain or lose muscle.

It’s pretty easy to measure muscle protein synthesis. Unfortunately, the same can’t be said about muscle protein breakdown. It’s doable but requires very invasive procedures not feasible in most strength training studies.

To measure muscle protein breakdown, you have to attach isotopes to amino acids and infuse them intravenously, take blood samples from veins and arteries, and gather muscle biopsies. That’s just not on the table if you’re looking at how many milligrams of muscle you add from a set of biceps curls. Placing arterial catheters is something you do in the intensive care unit, not on healthy, strength-training men and women.

Even if, in theory, you’d spend time, resources, and pain on such an investigation, it would be of little use for strength-training research for several reasons.

You can’t use these methods if you’ve eaten. Eating brings amino acids from the meal into the picture, messing up the results.

Taking a biopsy destroys muscle fibers, making it hard to see from where the damage comes: from the muscle protein breakdown you’re looking for or from the invasive biopsy itself.

When you read that something you eat reduces muscle protein breakdown, any studies backing such claims are guesses based on indirect markers or measures ofwhole-body protein breakdown, not specifically muscle protein breakdown.

In other words: you can’t measure muscle protein breakdown in any straightforward way. 

Not only should you not worry about muscle protein breakdown, but it’s actually important for building muscle. It liberates amino acids you can then use to create new muscle tissue. Also, you probably need a certain amount of muscle protein breakdown if you want to build muscle. Your body gets rid of old and damaged muscle cells, making room for fresh ones. Recent research suggests no advantages to reducing muscle breakdown beyond what happens naturally by eating a healthy, protein-rich diet.25 26 27

In summary: no, muscle breakdown is not something you need to be concerned about. It’s a part of building muscle, and if you’re healthy, it takes care of itself.

Which Protein is Best for Reducing Muscle Breakdown?

Probably none. You might have heard or read that protein, especially “slow” proteins like casein, reduce muscle breakdown.

That’s not the case. Not directly. Insulin reduces muscle protein breakdown. Both carbs and protein make your pancreas release insulin, but it’s not the protein itself that reduces muscle protein breakdown when you drink a casein protein shake.28 Maybe if you eat 70 grams or more of protein in a single meal, but the amount of protein you need to stimulate muscle protein synthesis maximally does not reduce muscle breakdown.29

When you see ads for protein supplements claiming that the powder in question prevents muscle protein breakdown, it’s incorrect. It’s just the effect of the insulin release the protein produces. You get the same insulin release and the same anti-catabolic effect from any regular meal. And you only require moderately increased insulin levels to reduce muscle breakdown maximally, and higher insulin levels do not reduce muscle breakdown further.

Does Insulin Build Muscle?

Eating or drinking protein helps you gain muscle mass in several ways. The amino acids stimulate muscle protein synthesis, and insulin release decreases muscle breakdown.

However, insulin does not affect muscle protein synthesis.30 That’s an old notion based on animal trials. You might have read that insulin is the most anabolic hormone. That’s true if you’re a pig, and because humans are pig-like in many physiological ways, scientists believed it was the same with insulin.

However, once they checked it in human trials, they saw that insulin didn’t stimulate muscle protein synthesis at all, at least not at levels you can reach without injecting it. Instead, muscle protein synthesis is entirely dependent on amino acids. Yes, you need insulin for the amino acids to kick-start muscle protein synthesis and enter your cells, but fasting insulin levels are enough. And, because protein in itself leads to insulin release, you don’t have to worry about insulin at all to build muscle.

If you’re looking to prevent muscle breakdown, insulin is your friend, though. A dose-dependent friend, too! The more insulin, up to a point, the more your muscle breakdown goes down. However, that point is relatively low. As little as 20 grams of protein release enough insulin to reduce muscle protein breakdown as much as possible. You don’t need any carbs with the protein, not even after a workout when your muscle breakdown is more prominent than usual. In other words, sipping sugar-sweetened beverages for the sake of muscle breakdown is entirely unnecessary.

What’s the Difference Between Fast and Slow Protein?

A “fast protein” is a protein you absorb rapidly. You break it down quickly in your gut and intestine, and the amino acids appear in your blood soon after eating. The prime example of a fast protein is whey protein, and whey is the only really fast protein. You absorb soy protein isolate and protein from finely chewed red meat relatively rapidly as well, but not like whey.

A slow protein is, if you can believe it, a protein you absorb slowly over several hours. You have probably heard about the milk protein casein as being a slow protein, and it is, but there are slower ones. For example, you absorb the protein from eggs much slower.

Fast proteins stimulate your muscle protein synthesis in a more powerful way than slow proteins. That effect doesn’t last very long, though. After drinking a whey protein shake, your muscle protein synthesis returns to base levels only 2–3 hours later. 

Slow proteins, like casein, do not elevate muscle protein synthesis much above normal levels. On the other hand, slow protein keeps your muscle protein elevated a little for a much longer time.

If you only look at an isolated protein intake, fasting both before and after the meal and without eating anything else with the protein, a slow protein is the best option. It gives you the best protein balance over time. A fast protein stimulates muscle protein synthesis more, but the effect is over so fast that you don’t benefit as much from it if you’re not going to eat again for many hours. If you eat several protein-rich meals during the day, it probably doesn’t matter much, if at all, how you mix and match slow and fast proteins.

Once again, old and young people react differently. If you’re older, a fast protein like whey is better overall.31 Older muscles require more amino acids in the blood in a short time to react.

Do You Have to Drink a Protein Shake Immediately After a Workout?

That you have to pound the protein as fast as you can after a training session is a common belief. Preferably as soon as you finish your last set, but certainly before you leave the gym: the concept of an “anabolic window” after a workout where a protein intake leads to superior gains compared to some other time.

That is probably an outdated and incorrect belief. A meta-analysis of more than 20 studies with hundreds of participants found that eating or drinking protein close to a workout is associated with greater gains. However, and this is important, that association disappears if you take total protein intake into account. Any positive effects from protein close to a training session come from an increased total amount of protein, not by the timing itself.32

Without a doubt, an “anabolic window” does exist. However, it likely stays open far longer than a few minutes to an hour. After a strength-training session, your muscles are more sensitive to amino acids for up to 24 hours.33 During that time, you build more muscle every time you eat protein than if you hadn’t worked out.

A possible exception is if you train on an empty stomach. Lifting weights kick-starts your muscle protein synthesis even if you don’t eat anything before or after the workout, but your muscle breakdown will remain greater until you eat some form of protein. When you’re wholly fasted, you’re constantly losing a little muscle, and once you eat, you flip the switch and compensate for the fast over the day. Completely fasted strength training improves the balance between muscle protein synthesis and breakdown, but it can’t turn positive until you eat.

Therefore, if you lift before breakfast, it might be a good idea to eat something within a reasonable time. A few minutes this way or that don’t matter, but why spend hours in a catabolic state when you could be gaining muscle? Eat or drink some protein as soon as you can. There is no evidence that this practice leads to more muscle mass over time, but why take that chance? There is nothing negative about giving your muscles what they require after training. Fasting many hours both before and after your workouts seems unnecessary and probably counter-productive if you want results.

If you’ve already eaten a regular meal a couple of hours before working out, you’re not in a hurry to do so again after your training session. It won’t hurt to ingest protein again as soon as you can, but don’t stress over it. You can take a shower, go home, make dinner, and eat 60–90 minutes after your workout without worrying about losing out on any gains. A review article looking at the “anabolic window” phenomenon agrees with that conclusion.34

Read more: Is It Important to Eat or Drink Protein Quickly after Training?

Do You Need Carbohydrates After Working Out, or Is Protein Enough?

Protein is enough! Carbs do not contribute anything to muscle protein synthesis, and you don’t need them to utilize the protein for building muscle.35 36 Twenty grams of high-quality protein take care of muscle protein synthesis and muscle protein breakdown without added carbs.

Carbohydrates aren’t bad when you work out. On the contrary, they restore muscle glycogen and improve recovery. But if we’re talking about building muscle specifically, then no, you don’t need carbs after working out.

Which Is Better: Protein Before or After a Workout?

It probably doesn’t matter much. A whey protein shake has the same muscle-building effects if you drink it before a workout as after.37 38

You can’t use a pre-workout shake to build muscle until after the workout, though. Muscle protein synthesis stays at base levels during and after a training session, but it takes off 60–90 minutes later.39 40 Many more studies support post-workout protein compared to pre-workout. Almost no studies look at the effects of eating or drinking protein both before and after training. The few that do only look at muscle protein synthesis over a few hours, not at muscle growth over time.

Importantly, no evidence suggests that protein timing before, during, and after a workout is essential.41 Don’t worry about minutes. Your total protein intake is, by far, the most important factor.

Is a Protein Shake Better Than a Real Meal After Training?

Most studies give the participants a protein supplement, with whey protein, casein protein, and soy protein being the most common. It’s much easier to control protein intake with a standardized supplement rather than a mixed protein-rich meal. A couple of studies use “real food” instead of protein powders, but even then, we’re talking about specific foods, like milk, not steak and potatoes.

Regular cows milk is a phenomenal muscle-builder after a workout, and whole eggs stimulate muscle protein synthesis more than just the egg whites.42 43 Beef works fine, even though the muscle protein synthesis boost doesn’t equal that of milk protein.44

After your training sessions, you can sit down to a regular protein-rich meal and skip protein supplements entirely, and nothing suggests otherwise. As usual, it’s the total amount of protein that matters, not if you get it from foods or a shake. Protein supplements are convenient and inexpensive per gram of protein, but you don’t have to use them to build muscle.

Other nutrients and chemicals in regular foods may enhance the anabolic effects of the protein. For example, whole eggs stimulate muscle protein synthesis more effectively than the same amount of protein from egg whites. Which chemicals we’re talking about and how they interact with each other and the protein you eat remains to be discovered. A review article from 2018 speculates about it and takes the opportunity to conclude that sure, you can stick to a regular meal post-workout.45

Can You Build Muscle Without Animal Protein?

Sure you can! Probably just as good as long as you get enough protein. You might need a little more, though, since plant protein gives you less of the critical essential amino acids and is more difficult to digest.

The most studied plant-based protein in strength-training research is, without a doubt, soy protein. Research shows that soy protein stimulates muscle protein synthesis about as effectively as milk protein. Not quite at the level of whey protein, but greater than casein protein.

whey vs casein vs soy protein

Even though you might not stimulate muscle protein synthesis quite as well with soy protein as with whey protein, it doesn’t seem to matter in the long run. A meta-analysis did not find any differences in muscle growth or strength between animal protein and soy protein as parts of a mixed diet.46

What about an entirely plant-based diet? Now we’re entering unexplored territory. However, a recent study demonstrated that a vegan diet is as effective as a mixed diet with supplemental whey protein for building muscle and getting stronger.47 As long as you get at least 1.6 grams of protein per kilogram of body weight and day, you should be good.

In summary, available research shows that you build muscle without any animal-based foods or supplements, as long as your plant-based diet provides you with enough protein.

Does Drinking a Protein Shake Before Going to Bed Help You Build More Muscle?

When you sleep, your muscle protein synthesis declines compared to when you’re up and about during the day.48 Also, nighttime is when most people go without food for the longest, and in the fasted state, as you know, muscle protein breakdown is greater than muscle protein synthesis.

Therefore, it sounds logical and like a good idea to eat or drink some protein before bed. That way, you give your muscles access to amino acids to keep building muscle even while you’re sleeping. Whey protein is probably not the best choice because the anabolic effect only lasts a couple of hours, and the night is long. The most popular option is casein protein, and it’s also the most well-researched.

Studies show that drinking a protein shake before going to bed keeps muscle protein elevated throughout the night. Unfortunately, we’re not talking about muscle protein, but organs, skin, and guts.

Another issue with the available research is that in all studies in which one group receives a pre-bed protein shake, they also increase their total protein intake compared to the control groups. When that’s the case, how can you know if the benefits come from an overall greater protein intake or the timing of the pre-bed protein?

Despite these problems, long-term studies show that drinking or eating protein before going to bed leads to more muscle growth over time. At least if you’re young. The studies are not without issues, though, and we need more of them to be sure it’s not just a case of getting more protein throughout the day.49

But why not be safe rather than sorry? Ingesting 20–40 grams of protein before going to bed feels like an inexpensive and straightforward intervention. If nothing else, it’s a convenient way to boost your total protein intake, and we know that helps you build muscle.

Is It Harmful to Eat a Lot of Protein?

In the past, eating large amounts of protein was sometimes considered harmful for you, possibly damaging your kidneys and weakening your bones. Decades of research find no support for such claims.

The World Health Organization concludes that high-protein diets have no known detrimental effects on kidney function.50 In a year-long study, participants showed no ill effects on blood lipids or kidney and liver function despite eating more than 3 grams of protein per kilogram of body weight per day.51 That’s much more protein than anyone needs to build muscle effectively.

A recent analysis shows that eating a lot of protein compared to fat might reduce the risk of kidney disease, not the other way around.52

A long-term intake of 2 grams of protein per kilogram of body weight per day seems to be safe for all healthy individuals. Some scientists suggest a safe upper limit of 3.5 grams of protein per kilogram of body weight per day.53 That doesn’t mean that a higher protein intake than that is dangerous, just that there is no research looking at such amounts. In any case, eating that much protein is unnecessary for everyone.

If you don’t have any medical issues, you don’t have to worry about how much protein you eat. If you already have kidney issues or suffer from some other medical condition that makes eating a lot of protein a problem, you should, of course, ask your doctor before you go on a high-protein diet. But if you don’t have any such health issues, protein won’t cause them.


There you have it! 25 myths and facts about protein in one convenient package! Hopefully, it provided you with some exciting and valuable information about protein you can use in your own diet and training.

Good luck with your efforts in the gym, and don’t forget to get enough protein! It is the number one nutrient for building muscle, after all.

Further Reading

Find out how much protein you need with our nifty protein calculator!


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Andreas Abelsson

Andreas is a certified nutrition coach with over three decades of training experience. He has followed and reported on the research fields of exercise, nutrition, and health for almost as long and is a specialist in metabolic health and nutrition coaching for athletes. Read more about Andreas and StrengthLog by clicking here.