As proteins play a huge role in keeping us healthy and protein cannot be stored in the body, it is important that we maintain an adequate daily intake of protein.
The daily protein requirement can vary depending on the size of a person, their activity level, lifestyle, state of health, whether they are growing teenagers or actively trying to add more protein to their body in the form of muscle, as in the case of body builders.
People who are recovering from injuries or illnesses (such as cancer) can also have increased protein requirements, as the body will be working hard to replace cells that have been damaged during the injury or illness. Protein also keeps our immune system healthy, as the blood cells that fight infection need enzymes (which are proteins) to do their job, and antibodies are actually proteins themselves.
Pregnant and breastfeeding women have increased protein requirements in order to support the changes in the mother and provide the protein required for foetal growth and development.
For this reason, the recommended daily intake varies between individuals.
Daily protein requirements for non-training individuals
One approach to determining what your required daily intake is to consider whether you are aiming to increase muscle mass, or whether you are just aiming to maintain your current physique.
If you are aiming to maintain your physique, are not engaged in an intense training program and are not recovering from illness or injury, the table below from the NZ Nutrition Foundation provides a useful guide for your Recommended Daily Intake (RDI) of protein:
| Age (years) | RDI (grams/day) | |
| Infants/toddlers | 1-3 | 14 |
| Children | 4-8 | 20 |
| Boys | 9-13 | 40 |
| 14-18 | 65 | |
| Girls | 9-13 | 35 |
| 14-18 | 45 | |
| Men | 19-70 | 64 |
| >70 | 81 | |
| Women | 19-70 | 46 |
| >70 | 57 | |
| Pregnancy | 60 | |
| Breastfeeding | 67 |
Daily Protein Requirements for athletes
If you are aiming to add muscle to your physique or are an active athlete engaging in intense exercise, your daily protein requirements will be higher than those outlined in the table above. The bodybuilding community has used a rule of thumb for many years, where the Recommended Daily Intake is 1 gram of protein per pound of body weight, or 2.2 grams per kilogram of bodyweight. This has recently been supported by research - in a 2017 article published in The Journal of Nutrition, it was found that the daily protein requirements of young male bodybuilders was between 1.2 to 2.2 grams per kilogram of body weight.
Sources:
- https://nutritionfoundation.org.nz/nutrition-facts/nutrients/protein
- 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, https://academic.oup.com/jn/article/147/5/850/4584703