If you want science then start with Wikipedias articles:

• https://en.wikipedia.org/wiki/Human_digestive_system
• https://en.wikipedia.org/wiki/Dietary_fiber
• https://en.m.wikipedia.org/wiki/Liquid_diet

And then read all the references when you want to dig deeper.

It’s the optimal for our digestive system, of course in some cases like in the hospital or nursing home people have trouble with getting the correct diet they then get laxatives to help.

The task for dietary fibers is to give volume in the colon and give the peristaltic muscles something to do.

They have limited nutritional value.

When l don’t worry about family, work, mortgage or the long list of chores I’m pushing in front of me.

I mostly listen to books during the commute, and play a few games when time allows it.

Are we sure there’s not a balmer’s peak scenario for the teens with 12-16 hour screen time?