How much protein do you need to build and protect muscle mass ?

Protein and Muscle

Proteins are essential to life. They play a role in many of the body's functions, from building, repairing and maintaining muscle mass to synthesizing neurotransmitters and strengthening the immune system. 

 

For athletes, fitness enthusiasts and anyone looking to improve their body composition, gain strength or simply stay healthy, an adequate intake of quality protein is essential.

 

In the following lines, we focus on the role of protein in muscle building and on the best sources as well as the amounts to consume to support your physical activity and perform in your sport.

Proteins: the building blocks of muscle mass

The human body contains about 10-12 kg of protein, with approximately 43% found in skeletal muscle, 15% in blood and plasma1, and the remainder distributed across various organs and tissues. Proteins are long molecules made up of amino acids. These amino acids form chains of different lengths, so their sequence, shape and structure determine the role they play in our bodies. For example, one protein will become an antibody or an enzyme, while another will help repair a muscle after exercise. There are two types of amino acids1.

Essential amino acids (EAAs)

Our body cannot make them and they must be present in our diet. There are 9 essential amino acids:

  • Histidine

  • Isoleucine

  • Leucine 

  • Lysine

  • Methionine

  • Phenylalanine

  • Threonine 

  • Tryptophan

  • Valine

Branched-chain amino acids (BCAAs)

If you are at all interested in sports nutrition, you have probably already heard of it.

Of the 9 essential amino acids, Leucine, Isoleucine and Valine are of particular interest and are called the branched-chain amino acids (BCAAs).

They are distinguished by their molecular structure, which makes them particularly beneficial for athletes in muscle protein synthesis and glucose metabolism.

BCAAs play various important roles for sports lovers, particularly:

  • Muscle recovery: BCAAs can stimulate muscle protein synthesis and contribute to muscular growth. A minimum of 4 g per serving is considered influential for muscle synthesis.
  • Fatigue reduction: BCAAs may compete with tryptophan in the brain, potentially limiting serotonin production and delaying the onset of fatigue2.

We will come back to these amino acids and where to find them later on this page.

Non-essential amino acids 

Our body can make them by itself from essential amino acids or other nutrients. There are 11 of them:

  • Alanine

  • Asparagine

  • Aspartic Acid

  • Glutamic Acid

  • Glycine, Proline

  • Serine

  • Arginine

  • Cysteine

  • Glutamine

  • Tyrosine 

The last four, those in italics, are considered semi-essential: the body knows how to make them, but not always in sufficient quantities, depending on the circumstances (for example, when we're stressed or injured).

Muscle protein synthesis: finding a balance between building and breaking down muscle 

Unlike carbohydrates and fats, the body cannot store proteins for extended periods and protein turnover, the continuous process of protein degradation and re-synthesis, is essential for maintaining healthy muscle tissue. Moreover, all body organs are continuously renewed at their own rate, highlighting the importance of regular protein intake to support this ongoing process.

Muscle protein synthesis (MPS) is the biological process of repairing and building muscle tissue:

  • For muscle growth to occur, MPS must exceed muscle protein breakdown.
  • To maintain muscle mass, MPS must equal muscle protein breakdown.
  • Conversely, breaking down more muscle tissue than you build leads to muscle wasting. 

To optimize MPS, researchers recommend consuming 20-40g of protein per meal, distributing protein intake throughout the day, with a special care towards protein consumption post-exercise3.

If you want to learn more, have a look at our experts explaining the role of protein in your body.

Leucine: a key player in muscle growth

Leucine4-9, one of the three BCAAs, is particularly studied and interesting for athletes. Leucine can make insulin secretion more efficient, better regulating glucose levels and initiating muscle protein synthesis, thus aiding in muscle recovery and growth.

If you like numbers, the optimal dose of leucine is 0.05 g/kg/day, with most studies showing that a dose between 0.02 and 0.05 g/kg/day is ideal to maintain leucine status in the organism. Protein doses should contain 700-3000 mg of leucine and ideally be evenly distributed across the day, every 3-4 hours, for muscle mass building or maintenance.

These considerations lead us to our next point: how can you provide your body with sufficient protein (and leucine)?

0.05g
the optimal dose of
leucine 

300mg
of leucine and ideally

be evenly distributed 

across the day

Where can you find good sources of dietary protein?

With a few exceptions, all foods contain protein. Some contain more than others. And they can be found in both plant and animal products. 

Because protein is rarely found in foods alone, and to help control energy intake throughout the day, it's best to choose lean protein foods (low in fat) with little or no carbohydrate. 

Here are some of the most common examples.

Animal and plant-based protein

You can find great sources of protein in meat, fish, eggs, low fat dairy, legumes or tofu. Nuts also contain a good dose of protein but they're also high in fat and it's easy to overdo it. So use with caution and reasonable amounts! Finally, protein powders are also an interesting and versatile option.

Complete and incomplete proteins

As we saw above, proteins are made up of amino acids, some of which (essential amino acids) must be provided by the diet:

  • If a protein contains all the essential amino acids (plus a few non-essential ones), it is called complete. This is true of all animal proteins.

  • If a protein is deficient in one or more essential amino acids (i.e. contains none or too few), it is called incomplete. This is the case for the vast majority of plant proteins, with the exception of soya and quinoa. This is an important consideration for people who don't eat animal products.

In terms of muscle protein synthesis, complete proteins are superior to incomplete proteins, as they contain all 9 essential amino acids in sufficient quantities. That said, it is entirely possible to obtain these 9 EAAs from incomplete protein sources, by combining them carefully. 

As for leucine, it is admitted that 700 to 3000mg per meal were sufficient to trigger MPS. There's no need to get out your calculator: common portions of foods rich in complete proteins meet these criteria. In the case of incomplete proteins, you'll need to consume a slightly larger quantity, due to their low EAAs and BCAAs content.

How much protein do you need every day?

The classic advice, which can be found pretty much everywhere in textbooks, is 0.8 grams of protein per kilogram of body weight for healthy, sedentary adults.  
This equates to:

  • 55 grams of protein per day for a 68 kgs person.
  • 70 grams of protein per day for a 90 kgs person.

What these figures don't tell is that they are calculated to prevent all forms of malnutrition. And there's a big difference between simply avoiding protein deficiency and being healthy and in shape. 

Without necessarily talking about a high protein diet, and whether for children, athletes, the sick or the elderly, protein requirements are in fact higher than 0.8 grams per kilo.

What are the current recommendations?

The amount of protein you need6 depends on various factors, including your activity level and fitness goals. Actuel research indicates these daily requirements:

  • Sedentary adults: 0.8-1.2g per kg of body weight

  • Moderately active individuals: 1.2-1.6g per kg

  • Athletes and intense trainers: 1.6-2.2g per kg

  • Older adults: 1.2-1.6g per kg to prevent muscle loss

Is timing your protein intake necessary?

Nutrient timing refers to eating certain foods in certain quantities at certain times of the day, mainly in relation to physical activity. For athletes and general population alike, the International Society of Sports Nutrition (ISSN)9 recommends between 1.1 and 2g/kg/day of protein, divided into four to six intakes throughout the day. The optimal intake per meal or snack is approximately 0.3g of protein per kg of body weight, or about 20-40g. For very active people who train a lot, experts recommend consuming protein within 30 minutes post-workout to ensure optimal recovery.

Are proteins harmful to the kidneys? Debunking the biggest protein myth

Contrary to popular belief, healthy individuals can consume relatively high amounts of protein without negative health consequences. And, unless you have a very specific medical condition that requires you to eat a low-protein diet, or you only drink protein shakes with no fats or carbohydrates, it's actually very complicated to eat too much protein. 

On the one hand, protein is very satiating, and after a few days of eating a lot of protein, you probably won't be able to look at a chicken breast for a long time.

On the other hand, science has not yet clearly established what "too much protein" means for healthy people. Studies, some of them very long (up to two years), have shown that eating up to 4.4g of protein per kilo of body weight per day causes no health problems12: no worries about kidneys, liver, bones or metabolic functions. And for those who were physically active, there was an increase in muscle mass and a loss of body fat. Not bad.

If you're wondering what 4.4g of protein per kilo of body weight is, just imagine (if you weigh 70kg, for example) eating 5 steaks, each weighing 250g, every day. Or twenty egg whites, 5 times a day. For two years... In other words, such doses are unattainable for most people, even on purpose.

Focus on Dairy proteins

Milk proteins10-11 are particularly interesting for athletes due to their composition of two high-quality proteins: casein (80%) and whey (20%). These are complete proteins that contain great amounts of EAAS and BCAAs. The only source that exceed these amounts (gram for gram) is eggs.

Casein is considered a "slow" protein, slowly absorbed and releasing amino acids for 6-7 hours. Whey, on the other hand, is a "fast" protein, quickly absorbed and causing a high peak of amino acids in the blood for 3-4 hours.

The combination of whey and casein in milk proteins helps release amino acids in both short and medium-term, promoting muscle protein synthesis during a long period of time. While some studies suggest that different ratios of whey to casein may influence muscle metabolism, endurance, physical performance, and recovery, more research is needed to determine the optimal ratio for athletes.

In conclusion, protein is essential for muscle growth and repair, as well as for general health. By balancing your protein intake, choosing high-quality sources and optimizing distribution, you can support muscle function, body mass and performance at any age and activity level.

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  8. Komar, B., Schwingshackl, L., & Hoffmann, G. (2015). Effects of leucine-rich protein supplements on anthropometric parameter and muscle strength in the elderly: a systematic review and meta-analysis. The journal of nutrition, health & aging, 19(4), 437–446. https://doi.org/10.1007/s12603-014-0559-4

  9. Jäger R.,KerksickC.M.,CampbellB.I.,CribbP.I.,Wells S.D., SkwiatT.M., PurpuraM., ZiegenfussT.N., FerrandoA.A., ArentS.M., Smith-Ryan A.E., Stout J.R., Arciero P.J., Ormsbee M.J., Taylor L.W., Wilborn C.D., KalmanD.S., Kreider R.B.,WilloughbyD.S., HoffmanJ.R.,Krzykowski J.L.&AntonioJ.(2017).International Society of Sports Nutrition Position Stand: protein and exercise, Journal of the International Society of Sports Nutrition,14:1,DOI:10.1186/s12970-017-0177-8

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