The general Aubrey de Grey response to this observation is that yes, lifestyle improvements are great and diet/exercise are great for improving one's life. Howe

The general Aubrey de Grey response to this observation is that yes, lifestyle improvements are great and diet/exercise are great for improving one's life. However, it ends up conferring only a few more years of life. Some evidence he provides is that even very healthy (by obesity metrics for example) countries only have a life expectancy a few years longer than "unhealthy" countries. I think he cites like Japan (with lower obesity rates) having a life expectancy of 6 years longer than US (high obesity rates). Not my observation so feel free to caveat me away, but I'm just regurgitating what some doctors who studying aging observe and perhaps I'm not remembering all the evidence they provide.