Protein is the basic building block of the body. It is required to build and maintain all of the bodies structures such as muscles, skin, bone, cartilage and blood. It also plays an important role in the immune system, production of enzymes and hormones.

People who strength train will need about 1.2g to 2.2g of protein per kg of body weight to build muscle. 1, 2, 3

A longstanding rule of thumb from the world of Body Building is 1g per pound of body weight or 2.2g per kg.

Individual requirements will vary so experiment and track your results so see what works for you.

Experienced athletes may need to be at the higher end of the range. 4, 5, 6, 7

If you are creating a caloric deficit to lose fat, keep your protein at the top end of the range or higher to prevent loss of lean tissue. 8, 9, 10

Protein gives strong signals of satiety and helps regulate appetite.

As you age you are likely to need higher amounts of protein as protein utilisation becomes less efficient. 11, 12, 13

Intense activity e.g. running burns about 5-10g of amino acids per hour. So endurance athletes may want to factor this into their protein intake.

High protein intake has not found to be unsafe in healthy adults. 14

How much protein per meal?

Protein consists of amino acids. The amino acid leucine is responsible for most of the anabolic effects of a meal. We need around 2.5g to 3.5g of leucine (30g to 50g of protein) in a meal for the meal to contribute to protein synthesis. 15

Leucine content varies between different types of protein but some good sources are:

  • 130g of uncooked lean chicken breast contains about about 40g of protein / 3g of leucine.
  • 110g of uncooked lean steak contains about 33g of protein / 3g of leucine.
  • 50g of whey protein contains about 30g of protein / 3g of leucine.

(Source: Cronometer NCCDB)

Most plant proteins are low in the amino acid leucine so won’t have the same muscle building effect. On plant proteins you may have to supplement leucine or eat more overall protein or learn how to combine plant proteins to achieve a more complete amino acid profile.

The maximum amount of protein per meal that can be used for protein synthesis is unclear, but protein consumed above a protein synthesis threshold is not wasted as it has more uses in the body than solely muscle building.

To maximise protein synthesis, spreading your protein intake over the day in amounts above the leucine threshold may be an effective strategy as protein synthesis will be triggered several times.

What does this actually look like?

For a 70kg person:

Lower end of recommended range to build muscle:

1.4g of protein per kg bodyweight
= 98g of protein per day

200g steak = 50g protein
140g salmon = 30g protein
3 eggs = 24g protein
total 104g protein

Upper end of recommended range to build muscle:

2.2g of protein per kg bodyweight
= 154g of protein per day

250g of steak = 63g of protein
200g of chicken breast = 62g of protein
4 eggs = 32g of protein
total 157g of protein

I recommend the Cronometer app if you want to plan out your requirements.

Sources

  1. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance
  2. ACSM Information on protein intake for optimum muscle maintenance
  3. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training induced gains in muscle mass and strength in healthy adults.
  4. Increased Protein Requirements in Female Athletes after Variable-Intensity Exercise.
  5. Protein to Maximize Whole-Body Anabolism in Resistance-trained Females after Exercise.
  6. Indicator amino acid oxidation protein requirement estimate in endurance-trained men 24 h postexercise exceeds both the EAR and current athlete guidelines.
  7. Indicator Amino Acid-Derived Estimate of Dietary Protein Requirement for Male Bodybuilders on a Nontraining Day Is Several-Fold Greater than the Current Recommended Dietary Allowance.
  8. Dietary protein for athletes: from requirements to optimum adaptation.
  9. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes.
  10. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes.
  11. Protein turnover and requirements in the healthy and frail elderly.
  12. Increasing Dietary Protein Requirements in Elderly People for Optimal Muscle and Bone Health
  13. How To Eat For Maximum Muscle Growth At Any Age!
  14. Can eating too much protein be bad for you?
  15. Protein Nutrition, Muscle Health, and Weight Management ROLE OF PROTEIN DURING WEIGHT LOSS