How Much Protein Do I Need? The Definitive (and Evidence-Based) Answer

Once upon a time, I was stuck in a rut.

Despite training 5 to 6 days per week, my weight wouldn’t budge…I couldn’t get stronger…and I hadn’t built any muscle to speak of in years.

What is an aspiring little “shredder” to do?

Well, I consulted the prestigious annals of broscience and quickly found the answer:

Eat more protein. A metric f$%# ton, to be exact.

And so the great protein gluttony began. Every day kind of felt like this:

I double-scooped my protein shakes. I ate over a pound of meat per day. I popped hardboiled eggs like they were candy.

I was a good little bodybuilder… with (thankfully) good little kidneys. Thanks mom! (Just kidding–high-protein diets aren’t bad for your kidneys.)

Well, after a year of eating 400+ grams of protein per day… I had to face the facts.

It wasn’t working.

Despite all the gorging, I looked and weighed more or less the same and I was lifting more or less the same weights.

Nothing had changed, really.

Well…fool me once, shame on… shame on you. Fool me…you can’t get fooled again!

To my credit, I got wise, dramatically changed course with my diet and training, and finally escaped the crater of mediocrity. And along the way, I learned “little things” like how much protein to eat every day.

And here’s the long story short:

You don’t have to stuff yourself silly with protein to build muscle or lose fat, but you might have to eat more–or less–than you think.

And in this article, I’m going to break it all down for you. By the end, you’re going to know exactly how much protein you need to eat every day based on your goals and why.

Let’s get started then, with the fundamentals.

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What Is Protein and Why Is It Important?

Protein is a compound comprised of chains of smaller molecules known as amino acids, and it’s the basic building block of your body.

Your tissues such as muscles, ligaments, tendons, hair, organs, and skin as are all made from proteins, and so are hormones, enzymes, and various chemicals essential to life.

Your body requires twenty amino acids to form proteins.

It can produce eleven but must get the remaining nine from the food you eat. These are known as the “essential” amino acids and they are:

phenylalanine
valine
threonine
tryptophan
methionine
leucine
isoleucine
lysine
histidine

The primary reason you eat protein is to provide your body with adequate essential amino acids to continue building and repairing your body.

As you can imagine, regular weightlifting and exercise increases the body’s demand for protein, but adequate protein intake is important among the sedentary as well.

If sedentary folk don’t eat enough protein as they age, they will lose muscle faster. And the faster they lose muscle, the more likely they are to meet an untimely demise.

Quantity of protein, which we’ll talk more about soon, isn’t the only factor to consider, though.

Quality matters too.

What Are the Best Forms of Protein?

“I get plenty of protein–I eat broccoli.”

One of the more baffling things I hear regularly. (Even more puzzling is the claim that broccoli, gram for gram, has more protein than steak. DA GUBMENT IS LYING TO US!?1!?)

First, broccoli contains about 13 grams of protein per pound. which means people–and particularly physically active people–are certainly not getting enough protein through intake broccoli alone.

Second, not all forms of protein are of equal quality. Some are absorbed by the body better than others and amino acid profiles vary.

While it’s not true that plant proteins are “incomplete” (missing essential amino acids), it is true that some are lower in certain amino acids than other forms.

For example, animal proteins like meat, eggs, and dairy contain large amounts of essential amino acids. This is one of the reasons they’re popular among people eating a high-protein diet.

Let’s come back to broccoli and beef for a minute.

Here’s what 275 calories of each (4 ounces of steak vs. just over 9 cups of broccoli) will get you in terms of essential amino acids:

Essential Amino Acids	Steak	Broccoli
histidine	0.975	0.48
isoleucine	1.391	.0643
leucine	2.431	1.05
lysine	2.583	1.099
methionine	0.796	0.309
cysteine	0.394	0.228
threonine	1.221	0.716
tryptophan	0.201	0.269
valine	1.516	1.018

As you can see, it’s not even close.

You’d have to eat a 18 freaking cups of broccoli to get the essential amino acids found in just 4 ounces of steak.

This is the main reason why fruit and vegetables aren’t great primary sources of protein. You have to eat so much that it’s just impractical and, in some cases, they’re too low in certain essential amino acids.

The bottom line is your protein needs are going to be easiest met by animal sources but, with some creative meal planning (likely including protein powder), vegetarians and vegans can get plenty of high-quality protein in their diets.

How Much Protein Can Your Body Absorb?

Back when I was working on my PhD in broscience, I didn’t just eat 300 to 400 grams of protein per day–I also ate 8 to 10 times per day.

That meant I had to eat protein every two-ish hours and if I missed one of those meals, I would actually get hangry (hungry + angry).

Good times.

The main reason I used to do this is I had read…in a book…that your body can only absorb about 40 grams of protein in one sitting.

Any additional protein eaten beyond that threshold would be disposed of and thus unavailable for building muscle.

Thus, I had to plan my protein intake carefully lest I lose precious gainz.

You’ve probably heard this one too. Depending on whom you listen to, the limit might be higher or lower, but there is a ceiling.

Or is there?

Does it really make sense to think that an NFL linebacker’s body processes protein in the exact same way as a 105-pound jockey’s?

And if protein absorption were capped at a relatively low number, how exactly did we survive our hunter-gatherer days when we alternated between feasts and famines?

Well, let’s look for some answers, starting with what actually happens when you eat protein.

What Happens When You Eat Protein

Acid and enzymes in your stomach break the protein down into its constituents, amino acids. Some forms of protein, like whey, break down quickly, whereas others, like egg, take quite a bit longer.

The amino acids make their way into the small intestine, which contains special cells that transport them into the blood.

There are only so many of these “transporter” cells lining the intestine, limiting the amount of amino acids (and other nutrients) that can be ferried through each hour.

Thus, protein absorption rates are limited by:

How quickly protein is broken down into amino acids.
How quickly the amino acids are shuttled out of the small intestine and into the blood.

Let’s look at some concrete numbers.

According to one review, the human body can absorb approximately…

8 to 10 grams of whey protein,

6.1 grams of casein protein,

3.9 grams of soy protein,

and 2.8 grams of cooked egg protein…

…per hour.

These numbers aren’t going to hold exactly for all people and circumstances, but they clearly show that some forms of protein are absorbed quickly and others slowly.

Now, how do we get from here to the fallacy that the body can only absorb so much protein in one meal?

We grab research on how eating protein affects protein synthesis rates by the throat, put it in the gimp suit, and drag it on over.

Here’s how it goes…

The Truth About Protein Absorption

Studies like this found that 20 to 40 grams of protein stimulates maximal protein synthesis.

That is, 20 to 40 grams of protein in a meal is as anabolic as you can get and increasing intake beyond this amount accomplishes little-to-nothing in terms of muscle/tissue growth and repair.

This limit to protein synthesis is then construed as a limit to absorption.

If eating more protein doesn’t further elevate protein synthesis rates, the story goes, that must mean your body can’t “handle” any more, right?

Wrong.

How high protein synthesis rates go is only one dimension of what happens with them when you eat. How long they remains elevated is equally if not more important.

For example, research shows that 30 grams of whey protein spikes protein synthesis rates higher than 30 grams of casein does. But, due to whey’s rapid absorption, protein synthesis rates also fall back to baseline sooner.

(Whey causes a shorter, larger increase in protein synthesis whereas casein causes a smaller, longer increase. Casein also inhibits protein breakdown longer.)

The same thing happens when you increase the amount of protein eaten in a meal. Eat 60 grams of protein and the effects are magnified but not fundamentally modified.

Now, one other fallacy sometimes offered as limiting factor for protein absorption is the belief that all food moves through the small intestine in 2 to 3 hours.

If this were true, it would naturally follow that your body could only absorb so much protein before it exited the small intestine to be turned into poop.

It’s not true, though.

Protein, carbohydrate, and fat don’t move uniformly through the digestive tract, and they don’t leave sections in the same order that they arrived in.

When your stomach detects the presence of protein, a hormone is produced that delays gastric emptying. This hormone slows down intestinal contractions, buying your body the time it needs to absorb as much of the protein (amino acids) as needed.

The net effect is carbohydrate and fat can be processed and absorbed relatively quickly and your body can take its sweet time on its protein.

Definitive Proof That Your Body Can Absorb a Lot of Protein in One Meal

Not convinced this myth is dead yet?

I agree–protein absorption’s coffin could use a few more nails.

Here’s the first.

In this study, scientists separated 16 young, healthy women into two groups. One ate 79% of their daily protein (about 54 grams) in one meal and the other spread out across four meals.

These women weighed, on average, about 120 pounds, so 54 grams of protein in one meal was quite a lot relative to body weight.

After 14 days, researchers found no significant difference between in protein turnover, synthesis, or breakdown among the two groups.

Research on intermittent fasting lends insight as well.

This style of dieting calls for fasting for long periods of time and cramming your daily food into relatively short “feeding windows” ranging from 2 to 8 hours.

For example, the popular Leangains method involves alternating between a 16-hour fast followed by an 8-hour feeding window.

Well, in this IF study, subjects either ate on a normal diet or fasted for 20 hours and then had 4 hours to eat their meals for the day. After 2 weeks, researchers found no difference in protein metabolism between the two groups.

These findings have been replicated in several other studies as well.

The bottom line is if there is a limit to how much protein you can absorb in one meal, it’s really freaking high and thus a non-issue.

The takeaway, then, is you should simply eat tailor the size of your meals to your lifestyle and preferences and not worry if you’re eating too much protein in an individual meal.

How Much Protein You Should Eat to Build Muscle

You already know that exercise increases the body’s demands for protein, but by how much?

Well, according to a study conducted by scientists from McMaster University, protein intake of 0.6 to 0.8 grams per pound of body weight is adequate for maximizing protein synthesis.

Researchers noted, however, that more protein might be needed in the case of calorie restriction or frequent and/or high-intensity exercise.

A study conducted by scientists from The University of Western Ontario concluded the same.

For athletes, 0.6 to 0.8 grams of protein per pound of body weight is a good baseline and higher intakes are warranted depending on a wide variety of factors including energy balance, carbohydrate availability, exercise intensity, training history, and more.

Another good study on the matter comes from researchers at AUT University.

Here’s what the scientists concluded:

“Protein needs for energy-restricted resistance-trained athletes are likely 2.3-3.1g/kg of FFM [1 to 1.4 grams per pound of fat free mass] scaled upwards with severity of caloric restriction and leanness.”

All these findings agree with “gymlore” as well, which for decades now has prescribed 1 gram of protein per pound of body weight with slightly higher amounts while cutting.

I’ve personally found this advice workable too, both with my own body and with the thousands of people I’ve worked with.

So, my standard advice for protein intake when bulking is 0.8 to 1 gram of protein per pound of body weight.

How Much Protein You Should Eat to Lose Weight

Although you might say you want to lose weight, what you really want to do is lose fat (and not muscle).

And when that’s the goal, the research is crystal clear: a high-protein diet is far better for both losing fat faster and preserving muscle.

Research also shows that high-protein diets are easier to stick to because they result in less mood disturbance, stress, fatigue, and diet dissatisfaction than lower-protein diets.

Based on the same research cited in the section above, I recommend you eat 1 to 1.2 grams of protein per pound of bodyweight when cutting.

If you’re obese (a man with 25%+ body fat or woman with 30%+), then 1 to 1.2 grams per pound of fat-free mass is adequate.

Is There a “Best” Protein for Weight Loss?

If you want to dramatically increase sales of anything related to health and fitness, just tell people it’s going to help them lose weight.

Hence “weight loss” pills, pre-workout supplements, protein bars, and protein powders.

Well, while certain supplements can help you lose weight faster, there is no such thing as a “weight loss food.”

Some foods are more conducive to weight loss than others, though.

What this really boils down to is the amount of calories foods contain and how they break down into protein, carbohydrate, and fat.

Generally speaking, the best foods for weight loss are those that are filling and provide an abundance of micronutrients while also being relatively light in calories.

When you stick mainly to these types of foods during calorie restriction, you’re much less likely to struggle with hunger and cravings, which makes you much less likely to scuttle your weight loss efforts with overeating.

For example, my favorite “weight loss foods” are…

Lean meat (chicken, lean beef, fish, and so forth)
Low-fat dairy
Eggs and egg whites
Whole grains like wheat, brown rice, oats, and barley
Vegetables like green beans, carrots, broccoli, and cauliflower
Legumes like green peas and beans
Tubers like white potato, which is incredibly satiating, and sweet potato

As you can see, I focus on eating high-fiber, relatively unprocessed foods that taste great, provide my body with plenty of micronutrients, and keep me full.

The foods you want to avoid when dieting to lose weight are those that are very calorie dense, high in dietary fat and added sugar, but which aren’t all that filling.

Highly processed junk food like chips, candy, cookies, and other “goodies” and caloric beverages fit this bill, of course, but there are quite a few healthy foods that do as well.

For instance, I love cheese, oils, and butter, but have to limit my intake of them while dieting because they pack a ton of calories without doing much of anything to fill me up.

The same goes for foods like dried fruit, chocolate, avocado, fattier cuts of meat, and whole-fat dairy. All foods I love but avoid while dieting to lose fat because I have to eat too many calories of them to be satisfied.

What About Protein Powders?

The powders most suitable for weight loss would be those that are as close to pure protein as you can get.

As far as I’m concerned, any carbohydrate and fat in a protein powder is just “wasted” calories that I’d rather be eating.

In fact, drinking calories is generally a terrible idea when you’re dieting to lose fat.

The major problem with caloric beverages, ranging from fruit juices to soda to sports and energy drinks, is they don’t fill you up like food does.

You can drink 1,000 calories and be hungry an hour later. Eat a 1,000-calorie meal with a good amount of protein and fiber, though, and you will stay full for hours.

That’s one of the reasons why research shows that people that drink calories are much more likely to overeat than those that don’t. It’s also one of the reasons why there’s a clear association between greater intakes of sugar-sweetened beverages and weight gain.

The Bottom Line on How Much Protein You Should Eat

If you never read another article on protein intake again, you’ll do just fine. There just isn’t much else to it.

Sure, eating protein after a workout is advisable (and easy to do, so why not), but not vital. Whey protein and other powders are convenient but not necessary. Eating protein every few hours is no better for building muscle or losing fat than eating it 2 or 3 times per day.

So long as you hit your daily protein target and stick to high-quality sources, you can’t really screw up.