How Much Protein Do You Need to Build Muscle?

The foundation of Muscle Protein Synthesis

To understand the significance role protein plays in building muscle, it’s important to breakdown the concept of muscle protein synthesis (MPS). MPS is the process in which the body creates new proteins within the muscle cell specifically contractile proteins, actin and myosin. This process repairs and builds new muscle fibres in response to various stimuli with resistance training methods like weightlifting and bodyweight exercises being the primary factor.

Here is a simplified breakdown of how this process works:

• Micro tears occur during resistance training within muscle fibres
• Muscle cells send out mTOR signalling pathways
• Contractile Amino Acids myosin and actin are synthesised within the muscle cells
• Muscles repair and grow

Protein Intake and Muscle Mass

Research has concluded that a protein intake of approximately 1.6 grams per kilogram of body weight per day is the optimal amount for people engaged in resistance training to achieve maximal muscle protein synthesis. [01]

Achieving maximal muscle protein synthesis (MPS) is a vital objective for those pursuing resistance training, as mentioned previously it directly influences the capacity for muscle repair, growth, and overall adaptation to the demands of physical exercise.

The recommendation of 1.6 grams per kilogram of body weight strikes a balance between providing an sufficient supply of amino acids for MPS and avoiding excessive protein intake, which can lead to calorie surplus resulting in protein stored as fat, and potentially causing stress on the kidneys, although the debate remains unclear on the impact of protein on kidney function those with pre existing conditions should deter from a excessively high daily protein intake.

The body’s ability to utilise protein for muscle protein synthesis has its limits, and exceeding a certain threshold may not result in additional benefits for muscle growth.

It’s also important to note that various indicators, such as age, sex, training intensity, and overall health, will influence optimal protein requirements. Athletes or those engaged in more intense and frequent resistance training may find benefit from a higher protein intake, within the range of 1.6 to 2.2 grams per kilogram of body weight, to support their elevated protein turnover and muscle protein synthesis rates.

Timing and Distribution of Protein Intake

Why It may seem beneficial to consume large meals packed with high protein foods and a protein shake on the side to enhance your intake, it has been scientifically proven that consuming smaller amounts of protein spread evenly across meals has more impact on muscle protein synthesis. [02] For example consuming a meal consisting of 80g of protein would be less effective at maximising MPS vs consuming 20g of protein every 2 hours.

This ensures that the body has a sustained amount of amino acids available in the bloodstream, providing essential building blocks for maximising MPS.

The human body also has a limit on how much protein it can utilise in one sitting research states that consuming more than 20g-25g of protein per meal has no adverse effect on MPS in young men. [03]

Why Protein Quality Matters

Whey protein, promotes greater muscle protein synthesis compared to lower-quality proteins.

Protein quality refers to the extent of which a protein source provides the essential amino acids in the right proportions and is easily digested and absorbed by the body.

Whey protein is high in BCAA’s most notably leucine which is known for its stimulation of the mTOR pathway that initiates MPS, it is digested and absorbed quickly by the body providing the bloodstream a sufficient amount of amino acids making.

Casein protein is also high in BCAA’s however digestion is slowed down compared to whey protein, resulting in a more gradual release of amino acids making this source of protein more suitable for consumption before bed.

While soy protein contains a complete profile of BCAA’s it’s digestion falls compared with the previous two and therefore supplies the blood stream with a sustained release of amino acids over a period of time instead of the rapid release found in whey protein. Soy protein also contains less leucine limiting its role of stimulating MPS.

Therefore, Whey protein’s superiority is attributed to its rapid absorption and higher leucine content. The rapid digestion of whey protein leads to a quicker increase in amino acid availability in the bloodstream, and the elevated leucine levels contribute to a more potent stimulation of the mTOR pathway.[04]