The recommended dietary allowance for protein is 0.8 grams per kilogram of body weight per day. That figure appears on nutrition labels and in dietary guidance, and it’s widely read as a target.
It was established as the amount sufficient to prevent deficiency in most healthy adults. That’s a different question from the amount that best supports maintaining muscle mass as you age, and a growing body of research suggests the second number is higher.
Anabolic resistance
Muscle protein is in constant turnover — continuously broken down and rebuilt. Net muscle mass reflects the balance between the two.
Eating protein stimulates muscle protein synthesis. In younger adults, a modest amount produces a robust response.
In older adults, the same amount produces a blunted response. More protein is required to achieve comparable stimulation of muscle protein synthesis. This phenomenon is described as anabolic resistance, and it’s one mechanism by which muscle mass declines with age even when intake appears adequate on paper.
The practical consequence: the amount that maintained your muscle at thirty may not maintain it at sixty.
What the research suggests
Reviews and expert groups examining protein requirements in older adults have generally converged on recommendations above the RDA. Commonly cited ranges fall around 1.0 to 1.2 grams per kilogram daily for healthy older adults, with higher figures — often 1.2 to 1.5 — suggested for those who are physically active, recovering from illness, or working to preserve muscle mass.
For a 75-kilogram person, that’s a difference between roughly 60 grams and 90 to 110 grams daily. Substantial, and not achievable by accident.
These are recommendations from the literature rather than universal requirements, and individual needs vary. Kidney disease in particular changes the calculation, which is why higher intake should be discussed with a clinician if you have any renal impairment.
Distribution matters too
Total daily intake isn’t the only variable. How it’s spread across the day appears to matter for muscle protein synthesis.
Muscle protein synthesis appears to respond to a threshold amount of protein per meal rather than scaling smoothly with any quantity. Commonly cited figures for older adults suggest roughly 25 to 40 grams per meal to reliably trigger the response.
Most people’s intake is heavily skewed. A minimal breakfast, a moderate lunch, and a large dinner containing most of the day’s protein. This pattern can hit a reasonable daily total while only crossing the per-meal threshold once.
Redistributing toward three meals each containing an adequate amount appears to produce better outcomes than the same total concentrated in one.
What this looks like in food
Approximate protein content:
- 100g chicken breast: around 30g
- 100g salmon: around 25g
- 3 large eggs: around 18g
- 1 cup Greek yogurt: around 20g
- 200g cottage cheese: around 25g
- 100g firm tofu: around 15g
- 1 cup cooked lentils: around 18g
- 30g whey protein powder: around 25g
Reaching 30 grams at breakfast is where most people struggle. Eggs alone rarely get there. Greek yogurt, cottage cheese, or a protein supplement added to an existing breakfast is usually the simplest fix.
Plant versus animal sources
Plant proteins are generally lower in leucine, an amino acid that appears particularly important for triggering muscle protein synthesis, and several plant sources are limited in one or more essential amino acids.
This doesn’t make plant-based diets inadequate. It means paying more attention to total quantity and to variety across sources. A plant-based eater aiming for the same effect may need somewhat higher total intake and should combine sources across the day. Soy, in particular, has a more complete profile than most plant proteins.
Protein alone doesn’t build muscle
Worth stating plainly: adequate protein enables muscle maintenance and growth. It doesn’t cause it.
The stimulus is mechanical loading. Without resistance training, additional protein doesn’t produce additional muscle — it’s the permissive condition, not the driver.
The combination is what works. Loading provides the signal; protein provides the material. Either one alone substantially underperforms.
The reasonable summary
If you’re over forty and interested in maintaining muscle mass, the RDA is probably a floor rather than a target. Something in the range of 1.2 grams per kilogram daily, distributed across three meals of roughly 30 grams each, is consistent with what the research on older adults suggests.
Pair it with resistance training two or three times weekly. Discuss it with a clinician if you have kidney disease.
And notice that this is one of the few areas where the effort involved is mostly a matter of restructuring what you already eat rather than adding something new.
Understanding where you stand today is the first step. A comprehensive assessment looks at these markers together, in the context of your history and your goals.
This article is general education from the Nextgenlongevityhealth clinical team. It is not medical advice, does not establish a provider–patient relationship, and is not a substitute for evaluation by a licensed clinician who knows your history. If you are experiencing a medical emergency, call your local emergency number.