respiratory quotient

"Old people are able to metabolize fat at the same rate as younger people, but their overall metabolic rate is lower, because they are unable to oxidize sugar at the same high rate as young people. Fat people have a similar selectively reduced ability to oxidize sugar." -Ray Peat Resting...

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2657169/ Abstract Growth hormone (GH) signaling influences longevity in mice, with decreased GH signaling associated with longer life span and increased GH signaling with shortened life span. A proposed mechanism through which GH signaling influences...

maybe if not taken with lot of carbs/sugar http://www.ncbi.nlm.nih.gov/pubmed/16076989 http://www.ncbi.nlm.nih.gov/pubmed/10584049 http://www.ncbi.nlm.nih.gov/pubmed/19176733 http://www.ncbi.nlm.nih.gov/pubmed/16366740 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2621121