“…Many phenotypic characteristics shared by these mutants are believed to represent mechanisms of extended longevity. These characteristics include improved insulin sensitivity and glucose clearance (Bartke, ), altered energy metabolism manifested by increased mass and activity of BAT (Darcy et al, ; Li, Knapp, & Kopchick, ), decreased respiratory quotient (RQ) and increased oxygen consumption (VO 2 ) per unit of body mass and heat production (Westbrook, Bonkowski, Strader, & Bartke, ), which, surprisingly, are associated with reduced body temperature (Hauck, Hunter, Danilovich, Kopchick, & Bartke, ; Hunter, Croson, Bartke, Gentry, & Meliska, ).…”