I’ve had the same supper for 10 years

Fiber does have a health impact as you say, and having good health is one of the main ways known to delay death. And what is survival but the delay of death?

My point is that by eating a larger variety of nutritious food, you are less likely to suffer from poor health due to a lack of something you need.

Who knows when his first stroke was? His sister's history of stroke as well could indicate that there is something more going on. He could have had multiple microinfarcts over the years leading to a mild form of vascular dementia with cognitive impairment or something.

He probably isn't holding the secrets of the universe in his noggin, but cut him some slack. I'd have tea with him. Sounds like a chill guy.

It's not the variety of the diet but the quality of the food itself. Bread is good for energy, but if all you're eating is bread, you're not getting complete proteins, omega 3s, and other nutrients. It's fine, however, to eat nothing but meat and many societies did this for hundreds of thousands of years.

Farming is anything but sedentary, especially in the 19th century and prior. People's height was stunted because food was not abundant enough. Agricultural societies tended to grow faster than farming productivity could keep up with. A lot of people were simply malnourished and therefore never reached their natural height capacity.

But as you say, the hunter / gatherers such as the native Americans were taller on average than the first European settlers to arrive in America. This is not due to a particularly diverse diet. Most cultures subsisted on meat from hunting (largest source of nutrition) and a select few vegetables. The difference is that hunter / gatherer societies tended to self regulate their population according to available resources.

Experience is, broadly speaking, able to be considered as a spectrum with both vast breadth, and depth. I believe this holds true not only for external experiences, in this instance cuisine, but also for internal qualia and more compounded experiences.

It is, to my understanding, widely accepted that people are capable of living lives that can be vastly alien to what we might consider ‘consensus reality,’ or everyday life, more loosely. Look towards monks, yogis, and more briefly, psychonauts as examples of living beings with, presumably, internal lives vastly different to our own. Yet in those people we hear accounts of deep personal satisfaction, even euphoria, from no external source. Contentness, at a minimum, doesn’t demand a minimum breadth of experience, or any experience at all, as a prerequisite.

I’d go so far as to argue that the small-mindedness you’ve presumed of this man, may be an acute reflection of your own base assumptions about others.

It pays to be mindful that others lead lives as rich, meaningful, and subjective as your own, even if the set of experiences in question may vary vastly.

I see no good reason to not take this man on his word when he says he truly is satisfied with his life, particularly when he’s at a point where he can reflect back on it – something not afforded to those of us still living what we can only hope to be the bulk of our lives.

Everything I’ve written prior notwithstanding, let me ask: do you actively go out of your way to try every new experience possible to you, costs be damned? If you answer no, then you accept that there’s a radius you choose to set, within which you’re satisfied knowing that the experiences you’ve had thus far, and their costs, are in equilibrium, and that you’re content with not exceeding that boundary. Who are you to say that his ‘smaller’ radius of experience, ignoring the incredible amount of contemplative time afforded to this man, and what that may imply for his internal life experiences, is any less of a valid choice than yours is? Surely you’d then accept you very likely fall within a subset of a larger radius of possible experiences, of which there are people willing to explore past the boundaries you’ve set for yourself.

Ignorance may in fact be bliss, but I wouldn’t be so quick to assume this man is the ignorant party here.

"Disclaimer": migrant myself. Not necessarily my dream to go back "once retired". But my wife yearns for her motherland. And so do many.