Deathbed Conversion
It has long been know that reducing calorie intake can extend lifespan in yeast, fruit flies, and mice and probably for humans as well. I figured as did most people that less calories mean less damage to cells due to stress from the oxidation of sugar. Cells burn sugar somewhat like a car burns gasoline and so the theory goes if you eat less food you were putting fewer miles on your internal engine.
But now it seems like
that isn't true. The rate of death in fruit flies put on a restricted diet slows down within just a few days no matter how old the flies were. That seems to mean that animals of any age can benefit from a restricted diet. It seems more likely now that what happens is that the body goes into "starvation mode" very quickly when food is scarce and that animals live longer in this regime.