Comment by dp-hackernews

No mention of how a persons lifestyle changes over that period though.

Surely there is a correlation to the causation?

The head-bone is connected to the neck-bone etc...

You cannot study figures in isolation and expect them to yield some meaningful results while ignoring the influence of other figures upon those results.

- Kids move around a lot, and they're still growing/developing

- Teenagers move more constructively i.e. sports, and they're still growing/developing

- Adults move a bit less, and have almost stopped growing/developing

- Older adults try do keep moving, but with other life responsibilities it gets hard to put the same time in

- Older adults become less and less bothered about moving

- Even older adults have acquired illness and injuries and can't move as much

Seems quite simple and obvious no? - Maybe...

Those that don't fit the mould have some other reason that makes then more of an outlier to the norm.

If life today didn't offer as much assistance as the past, we would all be a lot more healthy - not to mention more active, you know walking and manual work etc...

Not to forget that the abundance of food (good and bad) will have a bearing on the results. Maybe the older people that can't afford as much food are the outliers - and better benchmark.

Unless you are suffering from malnutrition, or you are overeating the wrong sort of food (good and bad) then your metabolism, unless affected by biological factors should be pretty stable.

Isn't this what being in homeostasis means?

Doesn't the body adapt to effects of S.A.I.D. - Specific Adaptations to Imposed Demands.