The daily protein amount recommended for everyone (0.8 grams per kilogram of body weight) comes from studies done only on older men who weren't very active. So this amount might not be right for people who are active and lift weights or exercise regularly.
See the scientific wording
The protein intake recommendation of 0.8 grams per kilogram of body weight per day is derived from research conducted on older, physically limited men, and this recommendation may not be applicable to active individuals who engage in weightlifting or regular exercise.
There's disagreement
Randomized trialsThe 3 studies we reviewed point in different directions — there's no clear consensus.
What the research says
3 studies reviewedSupporting (1)
Randomized Controlled TrialHuman2023
The study gave older men either the usual recommended protein amount (0.8g/kg) or double that (1.6g/kg) while they lifted weights. Those who got double gained more muscle and strength, so the usual amount might be too low for people who exercise.
Contradicting (2)
Randomized Controlled TrialHuman2024
The study gave older women who lifted weights either the recommended amount of protein or a higher amount, and found that the extra protein didn't make them stronger or build more muscle, so the recommended amount seems fine even for active people.
Randomized Controlled TrialHuman2022
The study found that active older adults who ate extra protein didn't get stronger or perform better than those eating the recommended amount, so the usual protein recommendation seems fine for active people.
Quality-weighted scoring: we follow the GRADE framework — each study is rated High, Moderate, Low, or Very Low based on study design, methodology rigor, and risk of bias. A single high-quality RCT can outweigh several weaker observational studies.
Scores reflect study quality, not just count.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting, 2 contradicting studies
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