One-third of the way

An argument on Kevin Drum gives me a change to try some of the argument I had with Jo over lunch the other day.
"There are two points that emerge from a decade-long involvement in health promotion that are relevant to this debate.
1) Absolutely the only figure that counts in public health is the all-causes death rate. It's the only figure that takes all factors, plus or minus, into account (and it's the only figure that can't be gamed).
2) In Australia, at least - yanks are a much less good example - average life expectancy has for the last several decades been going up by four months a year. That's not bad; for one thing, it's one-third of the way to living for ever.
There are several further points that would seem to follow from this.
a) The "epidemic of obesity" can't be that bad for us, or it would be significantly cutting in to that rise.
b) A much smaller proportion of what matters for our health is under our own control than we think. Most of what counts is secular trends in our society."