best protein sources for muscle building

Best Protein Sources for Muscle Building – [Science-based]

Protein is important for muscle building. It provides sufficient amino acids to repair and create muscle. But not all proteins are the same. If you want to optimize your gains, you should aim for the best protein sources for muscle building.

In this post we'll talk about amino acids, types of proteins, plant-based and animal-based and their biological value.

Are you ready? Let's go!

By playing with both cards (resistance training and protein intake), you can aim for a positive net protein balance.

This is, your muscle protein degradation (MPD) is lower than muscle protein synthesis (MPS) (study).


Protein is important for muscle building. It improves muscle hypertrophy, performance, training session recovery, lean body mass, and strength (study).

How Much Protein Do You Need To Build Muscle?

Daily protein intake of 2-3g/kg seem to be optimal for muscle building.

This recommendations differ from the traditional dose of 0.8 g/kg established by the RDA (study) This is a mere preventive dose to avoid protein insufficiency, but you can definitely benefit of higher doses.


People that want to build muscle need higher protein doses (study).

This is because of the high energy demands, faster metabolism and high degree of muscle damage.

How much protein do i need to build muscle

How’s Protein Quality Assessed?

Not all protein sources are the same.

Protein sources differs on their amino acid profile, bioavailability, digestibility,... (study) The protein of an egg and legumes is not going to have the same effect on muscle building.

The main features to assess the quality of a protein source are:

  • Amino Acid Profile
  • Biological Value
  • Digestibility

Amino Acid Profile

Proteins are large macromolecules formed by amino acids joined together by peptide bonds and other molecular interactions (study).

There are 20 Amino Acids (Aa) forming all proteins known. Out of this 20Aa, only 9 are essential. As you cannot make them on your own, you need to take them through diet (study).

The remaining 11 Aa, you do make them endogenously, and although it's important to get them from the diet as well, is not strictly essential.

Amino Acids

The amino acid composition of a protein source determines its quality (study).

The Amino Acid Profile (study) can help you evaluate the quality and content of each protein source

If the protein source contains all essential amino acids, it's a complete protein. If it doesn't, it's an incomplete protein. Here we generally find plant sources (study)

Protein Sources

Plant proteins sources tend to have lower content in EAAs when compared to dairy products or other animal proteins.

Plant protein sources are generally defficient on methionine) and cysteine (study).

Leucine, the most important Aa for muscle protein synthesis (study) is considerably higher on animal protein sources.

Biological Value

Biological value measures protein quality by calculating the nitrogen used for tissue formation divided by the nitrogen absorbed from food (study).

This measurement gives an overview of how well is your body at using an specific protein source for metabolic work.

Biological Value

Taking the egg as reference with a result of 100, the highest grade is for whey protein (159), depending on the amino acid profile of the blend and the raw material.

Animal proteins sources are at the top of the table, followed by the vegetable sources.

The biological value takes into consideration the amino acid profile (study), and the lack of one or more essential amino acids makes vegetable sources rank lower on the table.

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Other Properties of Protein Sources

The presence of other macronutrients on the meal affects the way protein is absorbed, digested and used.

In this study (study), carbohydrates coingestion with protein delayed protein digestion.

The postprandial (after ingestion) protein accretion didn't differ from the other group, and the anabolic response was the same after all.


Fats seem to act the same way when co-ingested with protein sources (study).

Both cases affect delays digestibility, but the anabolic response doesn't differ.

The structure and composition of the protein doesn't change by the presence of other macronutrients.

Best Protein Sources for Muscle Building

Protein sources may differ on their amino acid profile, digestibility, biological value or the efficient ratio of amino acids being used for anabolism.

Based on these differences... what's the best protein source for muscle building?

Plant-based proteins for Muscle Building

The more complex nutritional matrix of these food sources show a slightly different protein's kinetics and digestion (study).

Plant-based protein foods do produce a lower anabolic response, but there are some strategies we can use to prevent that:

  1. Higher protein intake to provide sufficient amounts of all amino acids
  2. Mix protein sources to create a complete protein
  3. Intake of fortified foods with lacking Aa
Protein Sources for muscle building

In figure b), a  plant protein blend, composed of different plant-based proteins, showed a greater anabolic response than 20g plant protein alone. The same happened with 40g plant protein (study).


Animal Protein Foods for Muscle Building

Animal Protein, either we like or not (sorry vegetarian people), is the most effective protein source for anabolic response (study)(study).

Animal protein shows a high content in leucine. Leucine triggers and activates mTORC1, related to muscle protein synthesis (MPS) (study).


Whey Protein for Muscle Building

Whey protein and derived show the highest biological value, amino acid profile and leucine content.

Therefore, whey protein products are the best protein source for muscle building.

whey protein meme

Whey protein is high in cysteine. This amino acid has strong antioxidant functions (study), providing additional health benefits.

These include lower risk of cancer, fight of chronic oxidative stress and regulating the inmune system (study).

Casein is one of the best protein sources for muscle building. Its nutritional matrix is similar to that of whey protein, but with added calcium and phosphorus (study).

Casein, due to its nutritional matrix, prolongs and delays the anabolic response. This can come handful before going to bed or any other situation in where there won't be any protein intake for a long time (>6h)

Extra Benefits of Whey Protein as Protein Source for Muscle Building

Whey protein is one of the best protein source for muscle building. This is why:

  • Highest biological value
  • High content in leucine
  • Contains all essential Aa
  • Rapid digestion

Whey protein can also favour muscle building by other indirect mechanisms.


Antioxidant effect

Whey protein is a potent antioxidant food. It replenishes gluthatione (study), the most powerful antioxidant in your body (study).

This may help modulating excess oxidative stress after exercise.

Due to this, whey protein can potentially minimize muscle damage and recovery (study)

Increases Anabolic Response

Whey Protein increases the anabolic response when compared to other protein sources (study).

It also increases ribosome biogenesis (study). More ribosomes increase the rate of translation and protein synthesis, producing more proteins per unit of time.

What’s the Best Protein Source for Muscle Building?

What's the ultimate best protein source for muscle building?


There's no "ultimate best protein source". All protein sources have their 'pros' and 'cons'.

From TBS, we recommend you following a balanced nutrition, including different types of protein. 


Whey protein derived products show to be the best protein source for muscle building, but there are some aspects in where other protein sources win by.

Natural protein sources contain a better nutritional matrix. This complete nutritional matrix acts in synergy, helping digesting and activating anabolic pathways related to muscle building (study).

It's a mistake to think only protein affects MPS. A balanced diet rich in micronutrients increases the rate of MPS (study)

Types of Protein Sources


Whey Protein may be the best protein source for muscle building alone, but the nutritional matrix of other protein sources improves protein kinetics, absorption and potentially leads to higher long-term adaptations. Don't base your diet in a sole protein source. Vary different sources and create a nice balance between them.


Muscle building requires of high protein intakes to create a positive net protein balance. But not all protein sources are the same.

Aspects such as amino acid profile, biological value or protein kinetics affect the anabolic response. But what's the best protein source for muscle building?

In theory, whey protein shows to be the best protein source for muscle building. However, the nutritional matrix by which protein is contained in other protein sources may increase digestibility, kinetics and long-term anabolic response.

For this reason, we advice you not to depend solely of whey protein, and create a balance diet with different protein sources.

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