Valter Longo's research is essentially aiming to answer some of these questions. He was looking for the 80/20 point at which reduction in calories produces much

Valter Longo's research is essentially aiming to answer some of these questions. He was looking for the 80/20 point at which reduction in calories produces much the same outcome as fasting. His current position is expressed by the fasting mimicking diet; you might go read the papers in which he outlines trial results and the data that forms the basis for the diet. From a gene expression in mice point of view, none of it is exactly the same. Different but overlapping patterns of change for calorie restriction, isocaloric intermittent fasting, intermittent fasting with calorie restriction, methionine or other protein restriction, etc, etc. All different. Also, all the data on exercise shows it does little to life span in comparison to calorie restriction, while both are vaguely comparable when considering healthspan. There are plenty of papers on this topic to read. Again, completely different set of changes and benefits.