A week ago, in a Facebook group for CrossFit physicians, I read a post blaming poor parenting (i.e., poor mothering) for childhood obesity.
There and elsewhere I read confident statements on nutrition. I read confident statements about market movements (usually retrospective) and white men.
I always imagine these confident people are young, but I believe that is not always true.
There are likely things. There is entropy and death (but also the inexplicably low entropy of the early universe, and it is possible for an Old person to be stronger than they were in middle age).
Most things though, they are … complicated. They are some of this and some of that. If you cannot imagine a worse outcome than an obese child you have not opened your eyes enough, or lived long enough for the world to pin your eyelids back and burn reality into your retina.
Look for the Old of any age. Some have something that might be wisdom. Ask them about certainty.