CRD's are interesting but as far as I know the CRON diet bases it's idea of optimum nutrition on the USRDA. One problem with animal studies is we have no real quantitative comparison between the presumable needs of long lived mammals and humans. Humans can live on a pretty minimal amount or nutritive food, but is there such a thing as an optimal amount? for low level maintenance? for optimal healing? for optimal recovery from exercise? The RDA is hardly an adequate measure for everyone let alone me.