In a study to be published next month, the authors followed 652 healthy, non-diabetic Pima Indian volunteers for over a decade after measuring resting metabolic rate (RMR) or 24 hour energy expenditure (24EE). Their conclusion? Higher metabolic rates, whether measured by RMR or 24EE, was associated with greater mortality. The authors questioned how a faster energy turnover could accelerate aging as determined by mortality? Perhaps from increasing oxidative stress?
The take home point from this study is that we don't have all the answers, just more questions. But for now, I would consider this result a fluke rather than a trend.