Restricting the diet of animals led to them staying healthy longer and living longer.

“he finally did this ex this this experiment in rats and that in that one he'd let them live their entire lives and documented very convincingly how dietary restriction made in this case only females not males live longer and the interesting thing about mckay is that about a decade ago i was i was a visiting scholar in ithaca new york for a week and i went to the cornell libraries and i looked through all of his old papers and i don't think he ever really appreciated the significance of of what he'd done because he didn't really this was in the 1930s if i recall yeah this was in the 1930s and he was active until the 1960s but he got into producing you know high-protein bread and i'm making nutritional food for the military during world war ii and he really kind of dropped this whole thing so even though he made what in retrospect was really i think a landmark discovery i don't think he really appreciated that because he was never focused really on longevity”

“he noticed that his animals seem to be staying healthy longer and living longer when he fed them less”

“documented very convincingly how dietary restriction made in this case only females not males live longer”

“and documented very convincingly how dietary restriction made in this case only females not males um live longer”