I’m at the point where my peers complain about getting older.[1] And I’ve started wondering how much of that is really about age and how much is the cumulative effects of “lifestyle”. I mean if you sit in a chair for ten years for 12 hours a day you’ve probably become “too old” for doing cartwheels. But it could be reversed, maybe.
[1] Am I 25 or 50? Impossible to say in this climate of complaining.
Yeah, late 30’s with a bad hip from childhood illness and I still managed to shed 50 pounds and get stronger than ever after being very sedentary for years. Diet and exercise and no drugs (I’d for sure take Ozempic if it was affordable too). Just me, but I spent way too much time thinking I was getting old and I was wrong.
That doesn't seem to be what the study they cited said though.
Basically the common model was that metabolism steadily declines with age (for adults). The study cited[1] says that doesn't match their data.
What they found was that metabolism was higher than expected for kids 1-20, stable for adults 21-60, and lower than expected for senior adults 60+. [2]
I don't want to say thresholds but you can look at the figures and see the rapid increase (0-1), decline (1-20), stability (21-60), and decline again (60+).
So age probably matters more to metabolism (than we thought) for some age groups but not for other age groups.
And I don't think there was really anything about lifestyle other than this bit:
> consistent with the hypothesis that energy intake is coupled to expenditure
But obviously that won't help anyone lose weight (which is usually what people are complaining about when they complain about an assumed slowing metabolism) cause it's saying people take in more calories when they burn more calories.
Except for really old age, they mostly atrophy because of sedentarism. Even then, I've seen excellent climbers and alpinists past 70. Keep moving and your body will keep working.
Your muscles atrophy if you don't use them. A 60 year old power lifter is stronger than a 30 year old who never lifts. On average people lose around 5% of their muscle mass per decade after 30; someone with twice as much muscle mass at 30 is still going to have more muscle mass at 60 than the person who started at 30 with half as much muscle mass.
