Dry wit from Ouroboros on the very long-lived PEPCK-Cmus mice: "It's become reflexive to ask whether a long-lived mutant is living longer because it's calorie-restricted for some reason, incidental to the main phenotype conferred by the mutation, but this is not the case here: In order to preserve their enviable bods, PEPCK-Cmus mice eat 60% more than controls - so they're not extending their lifespan by dieting. If anything, they're anti-dieting: their increased metabolic efficiency means they’re harvesting more calories per gram of carb or fat than normal animals. No word yet on what happens if you do try to calorie-restrict them; I can imagine it going either way but am holding out hope for tiny explosions. ... The PEPCK-Cmus seem to have it all: great bodies, long lives, extended reproductive and sexual lifespans, and no need to limit their appetites. The down side? Apparently, they are complete assholes: the mutants are aggressive and hyperactive, traits heretofore unheard-of among muscular, fit humans (and, indeed, in the field of biogerontology)."