But it's already known and is being actively researched? E.g. low-calorie, high-nutrient diet has been demonstrated to improve life span in several species incl

But it's already known and is being actively researched? E.g. low-calorie, high-nutrient diet has been demonstrated to improve life span in several species including (non-human) primates, and that was all done already before 2000. Today's almost 2022.