91 year-old former U.S. Supreme Court Justice John Paul Stevens thinks he may have “jumped the gun” on retirement—he says his mind and body are holding up just fine. A spry Stevens recently told an AARP reporter in a taped interview that he also thinks “because generally people remain healthier for a longer period of time, it would perhaps be appropriate to increase the retirement age under the Social Security law.” Picking up where Stevens left off, are Americans actually living healthier and longer lives than they used to?

As it turns out, there’s good news and there’s bad news. First the good news: we’re living longer than ever. So says the Center for Disease Control, which found in March that American life expectancy in 2009 reached an all-time high of 78.2 years, a 0.2 increase from 2008. Now the bad news: compared to other developed countries, we’re way behind—a June study in Population Health Metrics ranked the US 37th in the world in life expectancy, with the typical American dying 3.2 years before a citizen of an average top-ten developed country. Much of this gap is related to obesity. Yesterday, the Trust for America’s Health released its annual “F as in Fat” report, the results of which grow more troubling each year. Twelve U.S. states are at least 30 percent obese, compared to one state above that mark four years ago. And no great surprise here—obesity reduces the life expectancy of a 50 year-old by 1-2 years, according to a 2010 paper by the Population Studies Center of the University of Pennsylvania. So what to do about the retirement age? Rather than venture there, The Study proposes to take a step back: it seems Americans need to change the nature of the work they're doing. In May, a PloS ONE study found that increasingly “sedentary” U.S. jobs have been a leading contributor to obesity.