Caloric restriction in rats led to a 40-50% increase in lifespan in early experiments.

“the first experiments were published in the early to mid 1930s right which means they were probably started in the 1920s right so almost a hundred years ago people were going down this this line of thinking of asking you know what is the effect of um significant restriction of calories on the aging process in mammals so the early studies were all done in rats and actually if if I remember correctly these studies were originally designed from a developmental perspective so they were really thinking about malnutrition um and its effects on development and as a product made the observation that yes when you restrict calories in a in a rat early on in life they have a smaller body size um uh but then if you let them live out their entire lives this is in the laboratory and I think that's really important to keep in mind you know they live 40 50% longer”