Eating less protein can make animals live longer.
See the scientific wording
Dietary protein restriction increases lifespan in animal models.
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 (2)
Randomized Controlled TrialAnimal2022
Yes, eating less protein made normal mice live longer, but it only works if they have a special hormone called FGF21. Without it, the same diet actually made them die sooner.
Randomized Controlled TrialAnimal2023
Scientists gave fruit flies less protein to eat, and those flies lived longer than flies that ate normal food.
Contradicting (1)
Neither caloric nor protein restriction increases the male lifespan of outbred short-lived fish
Cohort StudyAnimal2026
Scientists fed fish less protein, but those fish lived just as long as fish that ate normal protein, so eating less protein didn't make them live longer.
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 & 2 supporting, 1 contradicting studies
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