Calorie restriction and organ-specific biological age in a 2-year randomized trial
In a randomized trial, 2 years of calorie restriction slowed rises in some organ-specific biological age measures versus an ad libitum diet; effects differed by organ. [1]
Automatic summary · not editorially reviewed
The key findings
The analyzed subset comprised 185 participants: 120 assigned to calorie restriction and 65 to an ad libitum diet for 2 years. [1]
Relative to the ad libitum diet, calorie restriction attenuated increases in metabolic and cardiovascular biological age, while kidney age remained unaffected. [1]
The abstract describes organ-specific biological ages as surrogate endpoints and reports heterogeneous effects across organ systems. [1]
The source at a glance
- Study type / format
- Abstract of a randomized controlled trial (secondary analysis of a participant subset)
- Population / context
- 185 adults in a subset of a randomized controlled trial, with organ-specific biomarkers at baseline and at least one follow-up at 12 or 24 months.
- Summary based on
- Study abstract
- Original publication
- March 14, 2026
185 adults: calorie restriction versus ad libitum diet
The abstract reports a subset of 185 participants from the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy Phase 2 randomized controlled trial: 120 assigned to calorie restriction and 65 to an ad libitum diet. Participants were assigned to 2 years of sustained calorie restriction or the ad libitum diet. Organ-specific biomarkers were available at baseline and at least one follow-up at 12 or 24 months. Five organ-specific biological ages (cardiovascular, immune, kidney, liver, metabolic) and whole body age were assessed at both time points.
Supporting source [1]
Metabolic and cardiovascular age rose less with restriction
Relative to the ad libitum diet, calorie restriction attenuated organ-specific increases in biological age. The abstract reports the most robust effects for the metabolic system (-0.54 years at 12 months and -0.63 years at 24 months) and the cardiovascular system (-0.82 and -1.00 years), followed by whole body (-1.00 and -1.27 years) and the immune system (-0.65 and -0.62 years). Liver age increase was modestly slowed only at 24 months (-0.54 years), while kidney age remained unaffected. Participants with a higher dose of restriction (at least 12.4%) showed a more pronounced attenuation of increases in metabolic and whole body age.
Supporting source [1]
Abstract-only scope and surrogate endpoints
The abstract states that calorie restriction has heterogeneous effects on biological aging across organ systems. It describes organ-specific biological ages as sensitive surrogate endpoints for detecting early responses to anti-aging interventions and as practical tools for monitoring or targeting organ-specific aging. These are associations within a randomized comparison, not proof that calorie restriction extends human lifespan. The abstract does not report adverse events, the full diet protocol or how the biological age measures were calculated. Only the abstract was reviewed; the full text was not reviewed.
Supporting source [1]
How to interpret this
Abstract only; the full text was not reviewed. The abstract does not report adverse events, the full diet protocol or how biological age was calculated. Findings are associations within a randomized comparison, not proof of longer human lifespan.
Based on the study abstract; the full paper, tables and supplementary data were not reviewed.
Source & supporting passages
Li Y, Xu X, Sehgal R, He X, Zheng Y, Chen X, Xu K. · europepmc.org · March 14, 2026