Nutrition guide
Protein Intake By Age
Use the Australian and New Zealand adult protein reference table, then separate the effect of age from body weight, training and individual health needs.
Updated 16 October 2026 • Prepared by Tools by Layna Editorial Team
Adult protein reference values by age
The table shows the published recommended dietary intakes (RDIs) for healthy adults from the Australia and New Zealand Nutrient Reference Values. The g/day figures use reference body weights, while the g/kg figures express the associated body-weight basis. They are population reference values, not an individual prescription or a sports target.
| Adult age | Men: RDI | Women: RDI |
|---|---|---|
| 19–30 years | 64 g/day (0.84 g/kg/day) | 46 g/day (0.75 g/kg/day) |
| 31–50 years | 64 g/day (0.84 g/kg/day) | 46 g/day (0.75 g/kg/day) |
| 51–70 years | 64 g/day (0.84 g/kg/day) | 46 g/day (0.75 g/kg/day) |
| Older than 70 years | 81 g/day (1.07 g/kg/day) | 57 g/day (0.94 g/kg/day) |
What changes at older ages?
In this reference, the adult RDI is the same across 19–30, 31–50 and 51–70 years. The higher category applies to people older than 70. Turning 40 or 50 does not trigger a different row in this table.
The NRV authors note that evidence behind the higher older-adult requirement is limited. Illness, appetite, frailty and maintaining muscle can require individual dietetic assessment rather than simply multiplying a number.
Worked example: using the weight-based figure
For an illustrative 60 kg woman aged 45, 60 × 0.75 = 45 g/day. For a 60 kg woman older than 70, 60 × 0.94 = 56.4 g/day. These calculations demonstrate the two reference factors. The published 46 g/day and 57 g/day values are rounded reference-weight figures, so they need not exactly match every individual multiplication.
A clinician may choose a different weight basis or target in circumstances where current body weight is not a useful basis. More decimal places do not resolve that choice.
Age is only one part of the decision
Training goals, pregnancy, breastfeeding and medical nutrition can change the relevant advice. The table above covers non-pregnant, non-breastfeeding adults. It is not the infant, child or adolescent table, and an adult sports calculator should not be used to set a child’s diet.
For regular training, compare the separate activity-level guide. Then use actual food portions to see how your selected target fits your normal meals.
Frequently asked questions
Do I need a higher RDI as soon as I turn 70?
The published higher row is for adults older than 70. The 51–70 row includes age 70. Individual needs do not change abruptly on a birthday, so use health and dietetic context as well.
Is the adult RDI a muscle-building target?
It is a general nutrient reference. Sports nutrition guidance has a different purpose and population, so it should be shown separately.
Why do g/day and g/kg calculations differ slightly?
The listed daily amounts use reference weights and rounding. Multiplying a factor by a different person’s weight can give a different total.
Related calculators and guides
Sources and method
- Australian and New Zealand Nutrient Reference Values: protein — Adult RDIs, reference factors, life-stage exclusions and the older-adult evidence note.