Rhesus monkeys that ate 30% fewer calories than normal, starting between ages 7 and 14 and continuing for more than 20 years, died from age-related causes at 2.9 times lower rates and from any cause at 1.8 times lower rates than monkeys that ate without restriction.
See the scientific wording
Caloric restriction of approximately 30% in adult rhesus monkeys, initiated between 7 and 14 years of age and maintained for over two decades, is associated with a 2.9-fold reduction in the rate of death from age-related causes and a 1.8-fold reduction in all-cause mortality compared to control animals fed ad libitum.
Correlational — new studies may shift this
Randomized trialsOne low-scoring study links this claim to the outcome, but causation is not established.
What the research says
1 study reviewedSupporting (1)
Caloric restriction reduces age-related and all-cause mortality in rhesus monkeys
Cohort StudyAnimal2014
Monkeys that ate 30% less food than usual for over 20 years lived much longer and got sick less often from old age than monkeys that ate as much as they wanted. This suggests eating less might help primates, including possibly humans, live healthier, longer lives.
Contradicting (0)
No contradicting studies found yet
That doesn't mean it's settled — it just means no study has tested the opposite.
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.
Eating less food lowers the amount of energy the body processes, which reduces wear and tear on cells and allows the body to focus on repairing damage instead of growing and storing energy. This keeps cells healthier for longer and prevents the buildup of problems that cause aging and death.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting study
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Rhesus monkeys that ate 30% fewer calories than normal, starting between ages 7 and 14 and continuing for more than 20 years, died from age-related causes at 2.9 times lower rates and from any cause at 1.8 times lower rates than monkeys that ate without restriction.
Mechanism
1 studyEating less food slows down the body’s energy use, which reduces damage to cells and turns on repair systems. This keeps organs and tissues working properly for longer, preventing the diseases that usually kill older animals.
Eating less food lowers the amount of energy the body processes, which reduces wear and tear on cells and allows the body to focus on repairing damage instead of growing and storing energy. This keeps cells healthier for longer and prevents the buildup of problems that cause aging and death.
Caloric restriction reduces mitochondrial electron transport chain activity and lowers reactive oxygen species production in tissues
Reduced metabolic flux activates nutrient-sensing pathways that increase autophagy and proteostasis
Enhanced cellular cleanup removes damaged proteins, organelles, and macromolecules that accumulate with age
Suppressed accumulation of molecular damage preserves tissue function and delays onset of age-related pathologies
Delayed tissue dysfunction reduces incidence of fatal age-related diseases such as cancer, cardiovascular degeneration, and neurodegeneration
Evidence from Studies
Supporting (1)
Community contributions welcome
Caloric restriction reduces age-related and all-cause mortality in rhesus monkeys
Monkeys that ate 30% less food than usual for over 20 years lived much longer and got sick less often from old age than monkeys that ate as much as they wanted. This suggests eating less might help primates, including possibly humans, live healthier, longer lives.
Contradicting (0)
Community contributions welcome
Score Breakdown
No multi-axis breakdown available yet. The overall Pro / Against score above is the best signal.
- No clinical evidence is available; the score reflects mechanistic plausibility only.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Systematic Review of Long-Term Caloric Restriction Studies in Non-Human Primates for Mortality Outcomes
Systematic review and meta-analysis of all prospective cohort and controlled studies in rhesus monkeys comparing caloric restriction (30% reduction, initiated between 7–14 years, duration >20 years) to ad libitum feeding, with mortality from age-related causes and all-cause mortality as primary outcomes
Randomized Controlled Trial of 30% Caloric Restriction vs Ad Libitum Feeding in Adult Rhesus Monkeys for Long-Term Mortality
Randomized assignment of adult rhesus monkeys (7–14 years old) to either 30% caloric restriction or ad libitum feeding, followed for over 20 years, with death from age-related causes and all-cause mortality as primary endpoints
Prospective Cohort Study of Caloric Restriction and Mortality in Adult Rhesus Monkeys Over Two Decades
Prospective observation of two cohorts of adult rhesus monkeys (7–14 years at baseline): one group receiving 30% caloric restriction, the other ad libitum feeding, with mortality tracked for over 20 years
Long-Term Animal Model Study of 30% Caloric Restriction on Mortality in Rhesus Monkeys
Observational or non-randomized comparison of mortality in rhesus monkeys subjected to 30% caloric restriction initiated at 7–14 years and maintained for >20 years versus controls fed ad libitum
Case Report of Individual Rhesus Monkey with Long-Term Caloric Restriction and Extended Lifespan
Detailed documentation of a single rhesus monkey subjected to 30% caloric restriction initiated between 7–14 years and maintained for over two decades, with recorded cause and timing of death