Protein isthe most abundant macronutrient in our organism. It's responsible for a wide variety of functions, including muscle building.... b ut how much protein do I need to build muscle?
Proteins are large biomolecules composed of one or more chains of aminoacids (Aa). These aminoacids act as building blocks, joined together by a peptide bond, that gives robusticity and stability to the protein.
The peptide bonds, together with other molecular interactions, form the tertiary structure of proteins, totally essential for its function and activity.
Why are Proteins Important for Us?
Proteins are the most abundant biomolecules in our organism. The majority of the molecules in our organism are made of protein:
- Muscle fibres
- Membrane transporters
- Final product of gene expression
Protein to Build Muscle
Muscle is primarly made of proteins added in parallel to create the connective tissue. These proteins, mainly actin and myosin, will create the called 'actin-myosin bridges', which will contract your muscle.
If you want to build more muscle mass, two things are required:
- Resistance or strenght training
- Dietary protein intake
Resistance training will induce 'catabolism' during the session itself, increasing muscle protein degradation (MPD) and decreasing muscle protein synthesis (MPS) (study).
Dietary protein intakeis used as a source of Aa to refill and create new muscle tissue, so as to repair the damaged one (study). It promotes muscle growth by increasing production of anabolic hormones and regulating muscle building (study)
The balance between muscle protein synthesis and degradation will determine the extent of new muscle tissue created and/or repaired:
If muscle protein synthesis is lower than degradation, it affects muscle recovery, and you don't have enough amino acids to create new muscle.
When dietary protein intake is enough to overcome the catabolism and degradation taking place, you will build muscle over time.
MPS = MPD
In theory, if both terms are equal, we would be able to mantain our muscle mass without building any additional one.
How Much Protein Do You Need to Build Muscle?
However, that is not enough to build muscle. This data was based on nitrogen balance studies (study). However, new techniques suggest that for most people those recommendations are far low from the recommended intake.
You need more protein than that to build muscle And here is some evidence backing up this:
- A revision in the Journal of Sports and Science suggests 1.3-1.8g/kg for athletes, going to higher intakes of 1.8-2.0 g/kg if your energy demands and exercise are too intense or if you are in a caloric deficit
- This study reveals that low protein intakes leads to a higher muscle loss when compared to higher intakes to 1.4-2.4g/kg
- On this meta-analysis protein intakes above RDA provided more benefits on muscle mass and body composition.
- In this study higher intakes of protein of 2.5g/kg increased fat loss and increased muscle mass when compared to RDA
Recommendations on protein intake to build muscle
The RDA is a preventive dose to avoid health consequences related to protein deficiencies. However, when it comes to bone healt, cardiovascular events,... higher protein intakes provide more benefits than RDA (study).
Doses of 2-3g/kg are a good start for your protein intake. But here are some cases in where protein intake should be consulted with your doctor:
- IRenal dysfunction (study)
- Pregnant women (study)
- Cancer patients or an other severe disease (systematic review)
- Children and new-borns (study)
- Elderly and subjects with risk of sarcopenia (study)
Daily intakes 2-3g/kg of protein optimize metabolic health and muscle building.
Higher protein intakes could benefit slightly more, although the benefits are not worthy compared to lower doses.
- Protein is the most abundant macronutrient, with a wide variety of metabolic functions
- Protein balance between MPS and MPD will determine the creation/destruction of muscle mass over time
- Classical recommended doses of protein are based on a preventive measure to avoid health issues
- Intakes of 2-3g/kg show more benefits in relation to health and muscle building
The Best Protein Intake to Build Muscle
The general recommendation of 2-3 g/kg of protein varies depending on the person.
Different cases require different protein intakes, and the same person can also benefit from different protein intakes depending on the season and the context.
How much protein do you need on a calorie surplus
During a calorie surplus, you are in a excess of energy (study).
When doing a calorie surplus, muscle loss is not at risk (study). High protein intakes displace the other two macronutrients, carbohydrates and fats. This can have an impact on your diet:
- Carbohydrates are the main metabolic fuel (energy) and with a low satiety index. They are key for enhancing your training quality and performance
- Fats are the macronutrient with the highest density index. Providing 9kcal/g (the other two macronutrients provide 4kcal), fats are interesting to create more adherence to high calorie diets and avoid eating high food volumes.
We recommend protein intake sitting on the low range. This means that 2-2.3g/kg should be optimal for your muscle gains and preservation of muscle mass.
This is some evidence to back it up:
- In bodybuilders on their off-season, 1.6-2.2g/kg was enough and optimal to build muscle mass (study)
- In this review, 1.8-2.2g/kg showed better results for body composition and muscle mass when comapred to the subjects following the RDA recommendations (study)
- This study recommends 1.6-2.0g/kg for athletes to consume if the goal is muscle building (study)
If you are in a calorie surplus, take 2-2.3g/kg of daily protein.
How much protein should you take during a calorie deficit
Calorie deficit is the requirement #1 if you want to lose fat. But not everything is good...
The higher the caloric deficit, the higher the risk of muscle loss (study). Your body will respond to the low calories using your own molecules to produce energy
First, it will get it from fat mass and other tissues, but later muscle will come and muscle loss will increase.
During a calorie deficit, muscle protein degradation increases. To counteract this, you'll have to increase protein intake.
For those doing a calorie deficit and resistance training, I recommend protein intakes of 2.5-3g/kg.
- Higher protein intakes increased fat loss and decreased muscle loss (study)
- Recommendations for bodybuilder in 'prep' point out 2.3-3g/kg to be optimal for preserving muscle mass (study)
- Protein intake ranging from 1.8 to 3.7 g/kg succeeds at preserving muscle in amateur male bodybuilders (study)
Proteins are very satiating (study), and it can make the calorie deficit way easier
Higher protein intakes elevate the total energy expenditure (TEE) (study).
How to Optimize your Protein Intake
Reaching the recommended protein intake will make and provide 90% of the benefits of dietary protein intake. But if you are really into and want to make the best out of it, timing and distribution also plays a role in MPS and muscle hypertrophy (study).
Role of leucine on protein synthesis
Leucine is the most important amino acid for muscle protein synthesis (study).
It has the ability to trigger and activate anabolic pathways related to muscle protein synthesis such as the complex mTORC1 (study).
Doses of 0.045-0.05g/kg of leucine per meal are optimal for muscle protein synthesis. But this recommendation is only important when it comes to low protein intakes.
In the famous study of Chuward-Venne (study), 2.25g leucine added to 6.25g whey protein didn't show any added effect.
Although leucine is important for MPS, the ingestion of the other essential amino acids (EAAS) and sufficient protein is at the top of our priorities to optimize MPS.
How often should you eat protein?
Meal timing and how often you eat could make a difference on body composition, but it's just the 'cherry on the top'.
Meals every 2-3h is the best protocol for muscle building. But that highly depends on the composition of your meal.
Protein is absorbed at different rates depending on the nutritional matrix of your meal (study).
Follow the frame of protein intake every 3-4h. But in terms of muscle building, the overall intake is what matters the most.
- Overall protein intake quantity is the most important fact for MPS
- Leucine plays an important role initiating and triggering MPS, but it needs of the other amino acids to build muscle tissue and synthesize proteins
- Protein doses of 20-40g are optimal for MPS.
- Meal timing and protein distribution is not significant when it comes to the 'basis'. To get the most out of it, seek for a linear protein distribution and 3-4 high-protein meals
Depending on your calorie intake, sex, age,... protein intake may differ, but general recommendations of 2-3g/kg seem to be a feasible guide to optimize MPS.
Other factors such as leucine content, minimum dose or quality of the protein have an impact on muscle building
Go for 3-4 meals of 20-40g protein and 0.045-0.05g/kg leucine. Animal source protein are usually high in leucine, thus this last recommendation loses importance