There is a region in rural (ex-Soviet) Georgia where it is very common for persons to live to 100+ years. They farm organically, not because it is "healthier", but because they cannot afford chemicals (and, anyways, "That's how Grampa taught me.").
Most people smoke cigarettes and drink vodka regularly. They grow their own tobacco, cure it and smoke it. Their vodka is made on the farmstead with their own potatoes.
They eat meat, but probably not a lot...most of their livestock is utilized for pulling their plows, or providing them with eggs and dairy...yogurt is consumed daily.
It is common to have six generations of family living on the farm. when you ask the 106 year old matron how she does something,
the answer is "Like my Grandma taught me."
What little they eat that was not produced on the farm, most of it came from a neighbor's farm, or somebody else in the village.
Simple, but
natural life. When they need a new plow, they hitch the wagon to a horse, and head to the blacksmith's shop.
If their diet was changed, their history would probably end shortly thereafter.