It's pretty well established that in animal studies, animals that undergo caloric restriction live longer. https://en.wikipedia.org/wiki/Calorie_restriction

I haven't kept myself up to date on it, but I think I remember that it was more about changing an organism's biology early in life. If you're an organism that is going to burn less energy per day, then you are an organism that just has less entropy per day, and less side-effect damage to your cells because of it. I think that the gist of it?