What exceptional longevity can tell us about resting metabolism

A relevant but limited comparison

Paolisso and colleagues compared 15 healthy centenarians with younger and older groups. Estimated RMR was not higher than in the older comparison group before adjustment; it was higher after accounting for activity and disability [1]. Crucially, RMR was calculated using a formula rather than measured by indirect calorimetry.

The result is a lead for studying preserved energetic function, not proof that centenarians have unusually high measured RMR per kilogram. A selected group of survivors cannot reveal whether a metabolic characteristic caused longevity.

A second study of long-lived women

Rizzo and colleagues compared 28 long-lived women with 26 adult women and 27 younger elderly women. Their abstract reports higher resting metabolic rate in the long-lived group than in the elderly comparison group, with no difference from the adults [3]. This supports investigating preserved metabolism in exceptional longevity; it does not show that raising expenditure or intake promotes longevity.

The exact per-kilogram comparison requires the full methods and tables, which have not been verified for this article. The abstract alone cannot establish a threshold or describe the participants’ metabolism earlier in life.

Per-kilogram comparisons can change the answer

In a study of older active and sedentary men, an apparent RMR-per-kilogram advantage disappeared after accounting for the non-zero intercept in the relationship between RMR and body mass [2]. Dividing by mass can introduce differences related to body size rather than tissue-level metabolic superiority.

A stronger future study

Measure RMR directly under standard conditions, distinguish total mass from fat-free mass, and account for fat mass, activity, illness and medication. Report absolute expenditure, per-kilogram values and appropriately adjusted estimates. Compare centenarians with suitable older controls and acknowledge survivor selection.

For Paper 1, this is a measurement question about ratios. Paper 4 can connect resting expenditure with functional testing; Paper 6 can investigate ageing-related resilience. The proposed association remains exploratory, and neither this evidence nor a value near 25 kcal/kg/day establishes a longevity target.

Related working papers

Read the relevant PDFs: EPK–001 to 007 are the revised version 1.2 papers; EPK–008 to 010 are version 1.0 supplements. Earlier PDFs and DOI records remain on the paper archive.