Nobody starts a protein search neutral. You type the question, and the pages that come back are written by people who sell protein. That is worth naming out loud before quoting any of them.
So here is what the brands actually publish on their own websites, followed by what the expert bodies recommend, so you can see the size of the gap yourself.
What the brands say
- Optimum Nutrition — their support article states protein intake should vary between 1.4 and 2.0 grams per kilogram of body weight to support performance, and recommends most of it come from food, with powder as a top-up. For a 180-pound adult that is 114 to 163 grams a day.
- Legion Athletics — argues against the popular "1 gram per pound" rule and cites research supporting roughly 0.7 to 1.0 grams per pound (about 1.6 to 2.2 g/kg) as sufficient for most goals. For a 180-pound adult, 126 to 180 grams.
We also checked GNC, Orgain and Transparent Labs and could not find a specific published grams-per-kilogram figure on their own sites, so we are not attributing a number to them. If we cannot source it, it does not go on the page.
What the researchers say
- The RDA — 0.8 g/kg. A minimum to prevent deficiency in healthy adults, not a performance target, and it was not written with 60-year-olds in mind.
- PROT-AGE (2013) — healthy older adults 1.0 to 1.2 g/kg; active or ill older adults 1.2 to 1.5 g/kg. Paired with resistance training.
- ESPEN (2014) — essentially the same numbers, for the same population.
- Morton et al. (2018) — in a meta-analysis of 49 resistance-training studies, the muscle-gain benefit flattened at about 1.6 g/kg. Above that, the extra grams did very little.
Free download
The number is one thing. The food that gets you there is another.
The 45-Food Protein Cheat Sheet, four-day meal plans for meat, no-meat, and plant-based eaters, plus two high-protein smoothies.
Send it to me →Where they agree, and where they do not
The agreement is bigger than the disagreement. Everyone — brands and researchers — puts the useful range well above the 0.8 g/kg RDA. If you take nothing else from this page, take that.
The disagreement is at the top end. The brands' ranges start where the research ceiling sits. Optimum Nutrition's 1.4 to 2.0 g/kg and Legion's 1.6 to 2.2 g/kg both extend past the 1.6 g/kg point where Morton and colleagues found the muscle-building returns level off.
Which does not make them wrong, exactly. Extra protein above 1.6 g/kg is not harmful for healthy people — multiple systematic reviews have found no adverse effect on kidney function in adults with normal kidneys. It simply is not buying you more muscle. And it happens to be the range where you start needing a second tub of powder.
The number to use if you are over 50
- Staying active, holding what you have — 1.2 g/kg. The middle of the PROT-AGE range.
- Lifting weights, adding muscle — 1.6 g/kg. Where the research ceiling sits.
- Cutting calories — go higher, nearer 1.8 g/kg, because a deficit puts muscle at risk.
- Every case — 25 to 40 grams per sitting, because aging muscle needs a bigger dose to respond.
One thing no brand page leads with: every expert recommendation quoted above pairs protein with resistance training. The powder is the cheap half of the plan.
Get your number without a sales pitch attached — run the protein calculator →
Free, one page, no fluff
Get the 45-Food Protein Cheat Sheet
45 everyday foods with protein per serving, four-day meal plans for meat, no-meat, and plant-based eaters, and two high-protein smoothies.
No spam. Your email is never sold or shared. Unsubscribe anytime.
Where these numbers come from
- Optimum Nutrition support article — protein intake 1.4–2 g/kg
- Legion Athletics — How much protein do I need?
- Bauer J, et al. PROT-AGE Study Group position paper (JAMDA, 2013)
- Deutz NEP, et al. ESPEN Expert Group recommendations (Clinical Nutrition, 2014)
- Morton RW, et al. Protein supplementation and resistance training (BJSM, 2018)
- Ko GJ, et al. Renal health and protein intake above the RDA (Adv Nutr, 2018)